use crate::{
    display_map::{InlayOffset, ToDisplayPoint},
    hover_links::{InlayHighlight, RangeInEditor},
    Anchor, AnchorRangeExt, DisplayPoint, Editor, EditorSettings, EditorSnapshot, EditorStyle,
    ExcerptId, Hover, RangeToAnchorExt,
};
use futures::{stream::FuturesUnordered, FutureExt};
use gpui::{
    div, px, AnyElement, CursorStyle, Hsla, InteractiveElement, IntoElement, MouseButton,
    ParentElement, Pixels, SharedString, Size, StatefulInteractiveElement, Styled, Task,
    ViewContext, WeakView,
};
use language::{markdown, Bias, DiagnosticEntry, Language, LanguageRegistry, ParsedMarkdown};

use lsp::DiagnosticSeverity;
use project::{HoverBlock, HoverBlockKind, InlayHintLabelPart};
use settings::Settings;
use smol::stream::StreamExt;
use std::{ops::Range, sync::Arc, time::Duration};
use ui::{prelude::*, Tooltip};
use util::TryFutureExt;
use workspace::Workspace;

pub const HOVER_DELAY_MILLIS: u64 = 350;
pub const HOVER_REQUEST_DELAY_MILLIS: u64 = 200;

pub const MIN_POPOVER_CHARACTER_WIDTH: f32 = 20.;
pub const MIN_POPOVER_LINE_HEIGHT: Pixels = px(4.);
pub const HOVER_POPOVER_GAP: Pixels = px(10.);

/// Bindable action which uses the most recent selection head to trigger a hover
pub fn hover(editor: &mut Editor, _: &Hover, cx: &mut ViewContext<Editor>) {
    let head = editor.selections.newest_display(cx).head();
    show_hover(editor, head, true, cx);
}

/// The internal hover action dispatches between `show_hover` or `hide_hover`
/// depending on whether a point to hover over is provided.
pub fn hover_at(editor: &mut Editor, point: Option<DisplayPoint>, cx: &mut ViewContext<Editor>) {
    if EditorSettings::get_global(cx).hover_popover_enabled {
        if let Some(point) = point {
            show_hover(editor, point, false, cx);
        } else {
            hide_hover(editor, cx);
        }
    }
}

pub struct InlayHover {
    pub excerpt: ExcerptId,
    pub range: InlayHighlight,
    pub tooltip: HoverBlock,
}

pub fn find_hovered_hint_part(
    label_parts: Vec<InlayHintLabelPart>,
    hint_start: InlayOffset,
    hovered_offset: InlayOffset,
) -> Option<(InlayHintLabelPart, Range<InlayOffset>)> {
    if hovered_offset >= hint_start {
        let mut hovered_character = (hovered_offset - hint_start).0;
        let mut part_start = hint_start;
        for part in label_parts {
            let part_len = part.value.chars().count();
            if hovered_character > part_len {
                hovered_character -= part_len;
                part_start.0 += part_len;
            } else {
                let part_end = InlayOffset(part_start.0 + part_len);
                return Some((part, part_start..part_end));
            }
        }
    }
    None
}

pub fn hover_at_inlay(editor: &mut Editor, inlay_hover: InlayHover, cx: &mut ViewContext<Editor>) {
    if EditorSettings::get_global(cx).hover_popover_enabled {
        if editor.pending_rename.is_some() {
            return;
        }

        let Some(project) = editor.project.clone() else {
            return;
        };

        if editor
            .hover_state
            .info_popovers
            .iter()
            .any(|InfoPopover { symbol_range, .. }| {
                if let RangeInEditor::Inlay(range) = symbol_range {
                    if range == &inlay_hover.range {
                        // Hover triggered from same location as last time. Don't show again.
                        return true;
                    }
                }
                false
            })
        {
            hide_hover(editor, cx);
        }

        let task = cx.spawn(|this, mut cx| {
            async move {
                cx.background_executor()
                    .timer(Duration::from_millis(HOVER_DELAY_MILLIS))
                    .await;
                this.update(&mut cx, |this, _| {
                    this.hover_state.diagnostic_popover = None;
                })?;

                let language_registry = project.update(&mut cx, |p, _| p.languages().clone())?;
                let blocks = vec![inlay_hover.tooltip];
                let parsed_content = parse_blocks(&blocks, &language_registry, None).await;

                let hover_popover = InfoPopover {
                    symbol_range: RangeInEditor::Inlay(inlay_hover.range.clone()),
                    parsed_content,
                };

                this.update(&mut cx, |this, cx| {
                    // TODO: no background highlights happen for inlays currently
                    this.hover_state.info_popovers = vec![hover_popover];
                    cx.notify();
                })?;

                anyhow::Ok(())
            }
            .log_err()
        });

        editor.hover_state.info_task = Some(task);
    }
}

/// Hides the type information popup.
/// Triggered by the `Hover` action when the cursor is not over a symbol or when the
/// selections changed.
pub fn hide_hover(editor: &mut Editor, cx: &mut ViewContext<Editor>) -> bool {
    let info_popovers = editor.hover_state.info_popovers.drain(..);
    let diagnostics_popover = editor.hover_state.diagnostic_popover.take();
    let did_hide = info_popovers.count() > 0 || diagnostics_popover.is_some();

    editor.hover_state.info_task = None;
    editor.hover_state.triggered_from = None;

    editor.clear_background_highlights::<HoverState>(cx);

    if did_hide {
        cx.notify();
    }

    did_hide
}

/// Queries the LSP and shows type info and documentation
/// about the symbol the mouse is currently hovering over.
/// Triggered by the `Hover` action when the cursor may be over a symbol.
fn show_hover(
    editor: &mut Editor,
    point: DisplayPoint,
    ignore_timeout: bool,
    cx: &mut ViewContext<Editor>,
) {
    if editor.pending_rename.is_some() {
        return;
    }

    let snapshot = editor.snapshot(cx);
    let multibuffer_offset = point.to_offset(&snapshot.display_snapshot, Bias::Left);

    let (buffer, buffer_position) = if let Some(output) = editor
        .buffer
        .read(cx)
        .text_anchor_for_position(multibuffer_offset, cx)
    {
        output
    } else {
        return;
    };

    let excerpt_id = if let Some((excerpt_id, _, _)) = editor
        .buffer()
        .read(cx)
        .excerpt_containing(multibuffer_offset, cx)
    {
        excerpt_id
    } else {
        return;
    };

    let project = if let Some(project) = editor.project.clone() {
        project
    } else {
        return;
    };

    if !ignore_timeout {
        if editor
            .hover_state
            .info_popovers
            .iter()
            .any(|InfoPopover { symbol_range, .. }| {
                symbol_range
                    .as_text_range()
                    .map(|range| {
                        let hover_range = range.to_offset(&snapshot.buffer_snapshot);
                        // LSP returns a hover result for the end index of ranges that should be hovered, so we need to
                        // use an inclusive range here to check if we should dismiss the popover
                        (hover_range.start..=hover_range.end).contains(&multibuffer_offset)
                    })
                    .unwrap_or(false)
            })
        {
            // Hover triggered from same location as last time. Don't show again.
            return;
        } else {
            hide_hover(editor, cx);
        }
    }

    // Get input anchor
    let anchor = snapshot
        .buffer_snapshot
        .anchor_at(multibuffer_offset, Bias::Left);

    // Don't request again if the location is the same as the previous request
    if let Some(triggered_from) = &editor.hover_state.triggered_from {
        if triggered_from
            .cmp(&anchor, &snapshot.buffer_snapshot)
            .is_eq()
        {
            return;
        }
    }

    let task = cx.spawn(|this, mut cx| {
        async move {
            // If we need to delay, delay a set amount initially before making the lsp request
            let delay = if ignore_timeout {
                None
            } else {
                // Construct delay task to wait for later
                let total_delay = Some(
                    cx.background_executor()
                        .timer(Duration::from_millis(HOVER_DELAY_MILLIS)),
                );

                cx.background_executor()
                    .timer(Duration::from_millis(HOVER_REQUEST_DELAY_MILLIS))
                    .await;
                total_delay
            };

            // query the LSP for hover info
            let hover_request = cx.update(|cx| {
                project.update(cx, |project, cx| {
                    project.hover(&buffer, buffer_position, cx)
                })
            })?;

            if let Some(delay) = delay {
                delay.await;
            }

            // If there's a diagnostic, assign it on the hover state and notify
            let local_diagnostic = snapshot
                .buffer_snapshot
                .diagnostics_in_range::<_, usize>(multibuffer_offset..multibuffer_offset, false)
                // Find the entry with the most specific range
                .min_by_key(|entry| entry.range.end - entry.range.start)
                .map(|entry| DiagnosticEntry {
                    diagnostic: entry.diagnostic,
                    range: entry.range.to_anchors(&snapshot.buffer_snapshot),
                });

            // Pull the primary diagnostic out so we can jump to it if the popover is clicked
            let primary_diagnostic = local_diagnostic.as_ref().and_then(|local_diagnostic| {
                snapshot
                    .buffer_snapshot
                    .diagnostic_group::<usize>(local_diagnostic.diagnostic.group_id)
                    .find(|diagnostic| diagnostic.diagnostic.is_primary)
                    .map(|entry| DiagnosticEntry {
                        diagnostic: entry.diagnostic,
                        range: entry.range.to_anchors(&snapshot.buffer_snapshot),
                    })
            });

            this.update(&mut cx, |this, _| {
                this.hover_state.diagnostic_popover =
                    local_diagnostic.map(|local_diagnostic| DiagnosticPopover {
                        local_diagnostic,
                        primary_diagnostic,
                    });
            })?;

            let hovers_response = hover_request.await;
            let language_registry = project.update(&mut cx, |p, _| p.languages().clone())?;
            let snapshot = this.update(&mut cx, |this, cx| this.snapshot(cx))?;
            let mut hover_highlights = Vec::with_capacity(hovers_response.len());
            let mut info_popovers = Vec::with_capacity(hovers_response.len());
            let mut info_popover_tasks = hovers_response
                .into_iter()
                .map(|hover_result| async {
                    // Create symbol range of anchors for highlighting and filtering of future requests.
                    let range = hover_result
                        .range
                        .and_then(|range| {
                            let start = snapshot
                                .buffer_snapshot
                                .anchor_in_excerpt(excerpt_id, range.start)?;
                            let end = snapshot
                                .buffer_snapshot
                                .anchor_in_excerpt(excerpt_id, range.end)?;

                            Some(start..end)
                        })
                        .unwrap_or_else(|| anchor..anchor);

                    let blocks = hover_result.contents;
                    let language = hover_result.language;
                    let parsed_content = parse_blocks(&blocks, &language_registry, language).await;

                    (
                        range.clone(),
                        InfoPopover {
                            symbol_range: RangeInEditor::Text(range),
                            parsed_content,
                        },
                    )
                })
                .collect::<FuturesUnordered<_>>();
            while let Some((highlight_range, info_popover)) = info_popover_tasks.next().await {
                hover_highlights.push(highlight_range);
                info_popovers.push(info_popover);
            }

            this.update(&mut cx, |editor, cx| {
                if hover_highlights.is_empty() {
                    editor.clear_background_highlights::<HoverState>(cx);
                } else {
                    // Highlight the selected symbol using a background highlight
                    editor.highlight_background::<HoverState>(
                        &hover_highlights,
                        |theme| theme.element_hover, // todo update theme
                        cx,
                    );
                }

                editor.hover_state.info_popovers = info_popovers;
                cx.notify();
                cx.refresh();
            })?;

            anyhow::Ok(())
        }
        .log_err()
    });

    editor.hover_state.info_task = Some(task);
}

async fn parse_blocks(
    blocks: &[HoverBlock],
    language_registry: &Arc<LanguageRegistry>,
    language: Option<Arc<Language>>,
) -> markdown::ParsedMarkdown {
    let mut text = String::new();
    let mut highlights = Vec::new();
    let mut region_ranges = Vec::new();
    let mut regions = Vec::new();

    for block in blocks {
        match &block.kind {
            HoverBlockKind::PlainText => {
                markdown::new_paragraph(&mut text, &mut Vec::new());
                text.push_str(&block.text.replace("\\n", "\n"));
            }

            HoverBlockKind::Markdown => {
                markdown::parse_markdown_block(
                    &block.text.replace("\\n", "\n"),
                    language_registry,
                    language.clone(),
                    &mut text,
                    &mut highlights,
                    &mut region_ranges,
                    &mut regions,
                )
                .await
            }

            HoverBlockKind::Code { language } => {
                if let Some(language) = language_registry
                    .language_for_name(language)
                    .now_or_never()
                    .and_then(Result::ok)
                {
                    markdown::highlight_code(&mut text, &mut highlights, &block.text, &language);
                } else {
                    text.push_str(&block.text);
                }
            }
        }
    }

    let leading_space = text.chars().take_while(|c| c.is_whitespace()).count();
    if leading_space > 0 {
        highlights = highlights
            .into_iter()
            .map(|(range, style)| {
                (
                    range.start.saturating_sub(leading_space)
                        ..range.end.saturating_sub(leading_space),
                    style,
                )
            })
            .collect();
        region_ranges = region_ranges
            .into_iter()
            .map(|range| {
                range.start.saturating_sub(leading_space)..range.end.saturating_sub(leading_space)
            })
            .collect();
    }

    ParsedMarkdown {
        text: text.trim().to_string(),
        highlights,
        region_ranges,
        regions,
    }
}

#[derive(Default)]
pub struct HoverState {
    pub info_popovers: Vec<InfoPopover>,
    pub diagnostic_popover: Option<DiagnosticPopover>,
    pub triggered_from: Option<Anchor>,
    pub info_task: Option<Task<Option<()>>>,
}

impl HoverState {
    pub fn visible(&self) -> bool {
        !self.info_popovers.is_empty() || self.diagnostic_popover.is_some()
    }

    pub fn render(
        &mut self,
        snapshot: &EditorSnapshot,
        style: &EditorStyle,
        visible_rows: Range<u32>,
        max_size: Size<Pixels>,
        workspace: Option<WeakView<Workspace>>,
        cx: &mut ViewContext<Editor>,
    ) -> Option<(DisplayPoint, Vec<AnyElement>)> {
        // If there is a diagnostic, position the popovers based on that.
        // Otherwise use the start of the hover range
        let anchor = self
            .diagnostic_popover
            .as_ref()
            .map(|diagnostic_popover| &diagnostic_popover.local_diagnostic.range.start)
            .or_else(|| {
                self.info_popovers.iter().find_map(|info_popover| {
                    match &info_popover.symbol_range {
                        RangeInEditor::Text(range) => Some(&range.start),
                        RangeInEditor::Inlay(_) => None,
                    }
                })
            })
            .or_else(|| {
                self.info_popovers.iter().find_map(|info_popover| {
                    match &info_popover.symbol_range {
                        RangeInEditor::Text(_) => None,
                        RangeInEditor::Inlay(range) => Some(&range.inlay_position),
                    }
                })
            })?;
        let point = anchor.to_display_point(&snapshot.display_snapshot);

        // Don't render if the relevant point isn't on screen
        if !self.visible() || !visible_rows.contains(&point.row()) {
            return None;
        }

        let mut elements = Vec::new();

        if let Some(diagnostic_popover) = self.diagnostic_popover.as_ref() {
            elements.push(diagnostic_popover.render(style, max_size, cx));
        }
        for info_popover in &mut self.info_popovers {
            elements.push(info_popover.render(style, max_size, workspace.clone(), cx));
        }

        Some((point, elements))
    }
}

#[derive(Debug, Clone)]
pub struct InfoPopover {
    symbol_range: RangeInEditor,
    parsed_content: ParsedMarkdown,
}

impl InfoPopover {
    pub fn render(
        &mut self,
        style: &EditorStyle,
        max_size: Size<Pixels>,
        workspace: Option<WeakView<Workspace>>,
        cx: &mut ViewContext<Editor>,
    ) -> AnyElement {
        div()
            .id("info_popover")
            .elevation_2(cx)
            .p_2()
            .overflow_y_scroll()
            .max_w(max_size.width)
            .max_h(max_size.height)
            // Prevent a mouse down/move on the popover from being propagated to the editor,
            // because that would dismiss the popover.
            .on_mouse_move(|_, cx| cx.stop_propagation())
            .on_mouse_down(MouseButton::Left, |_, cx| cx.stop_propagation())
            .child(crate::render_parsed_markdown(
                "content",
                &self.parsed_content,
                style,
                workspace,
                cx,
            ))
            .into_any_element()
    }
}

#[derive(Debug, Clone)]
pub struct DiagnosticPopover {
    local_diagnostic: DiagnosticEntry<Anchor>,
    primary_diagnostic: Option<DiagnosticEntry<Anchor>>,
}

impl DiagnosticPopover {
    pub fn render(
        &self,
        style: &EditorStyle,
        max_size: Size<Pixels>,
        cx: &mut ViewContext<Editor>,
    ) -> AnyElement {
        let text = match &self.local_diagnostic.diagnostic.source {
            Some(source) => format!("{source}: {}", self.local_diagnostic.diagnostic.message),
            None => self.local_diagnostic.diagnostic.message.clone(),
        };

        let status_colors = cx.theme().status();

        struct DiagnosticColors {
            pub background: Hsla,
            pub border: Hsla,
        }

        let diagnostic_colors = match self.local_diagnostic.diagnostic.severity {
            DiagnosticSeverity::ERROR => DiagnosticColors {
                background: status_colors.error_background,
                border: status_colors.error_border,
            },
            DiagnosticSeverity::WARNING => DiagnosticColors {
                background: status_colors.warning_background,
                border: status_colors.warning_border,
            },
            DiagnosticSeverity::INFORMATION => DiagnosticColors {
                background: status_colors.info_background,
                border: status_colors.info_border,
            },
            DiagnosticSeverity::HINT => DiagnosticColors {
                background: status_colors.hint_background,
                border: status_colors.hint_border,
            },
            _ => DiagnosticColors {
                background: status_colors.ignored_background,
                border: status_colors.ignored_border,
            },
        };

        div()
            .id("diagnostic")
            .block()
            .elevation_2(cx)
            .overflow_y_scroll()
            .px_2()
            .py_1()
            .bg(diagnostic_colors.background)
            .text_color(style.text.color)
            .border_1()
            .border_color(diagnostic_colors.border)
            .rounded_md()
            .max_w(max_size.width)
            .max_h(max_size.height)
            .cursor(CursorStyle::PointingHand)
            .tooltip(move |cx| Tooltip::for_action("Go To Diagnostic", &crate::GoToDiagnostic, cx))
            // Prevent a mouse move on the popover from being propagated to the editor,
            // because that would dismiss the popover.
            .on_mouse_move(|_, cx| cx.stop_propagation())
            // Prevent a mouse down on the popover from being propagated to the editor,
            // because that would move the cursor.
            .on_mouse_down(MouseButton::Left, |_, cx| cx.stop_propagation())
            .on_click(cx.listener(|editor, _, cx| editor.go_to_diagnostic(&Default::default(), cx)))
            .child(SharedString::from(text))
            .into_any_element()
    }

    pub fn activation_info(&self) -> (usize, Anchor) {
        let entry = self
            .primary_diagnostic
            .as_ref()
            .unwrap_or(&self.local_diagnostic);

        (entry.diagnostic.group_id, entry.range.start)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{
        editor_tests::init_test,
        hover_links::update_inlay_link_and_hover_points,
        inlay_hint_cache::tests::{cached_hint_labels, visible_hint_labels},
        test::editor_lsp_test_context::EditorLspTestContext,
        InlayId, PointForPosition,
    };
    use collections::BTreeSet;
    use gpui::{FontWeight, HighlightStyle, UnderlineStyle};
    use indoc::indoc;
    use language::{language_settings::InlayHintSettings, Diagnostic, DiagnosticSet};
    use lsp::LanguageServerId;
    use project::{HoverBlock, HoverBlockKind};
    use smol::stream::StreamExt;
    use unindent::Unindent;
    use util::test::marked_text_ranges;

    #[gpui::test]
    async fn test_mouse_hover_info_popover(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                hover_provider: Some(lsp::HoverProviderCapability::Simple(true)),
                ..Default::default()
            },
            cx,
        )
        .await;

        // Basic hover delays and then pops without moving the mouse
        cx.set_state(indoc! {"
            fn ˇtest() { println!(); }
        "});
        let hover_point = cx.display_point(indoc! {"
            fn test() { printˇln!(); }
        "});

        cx.update_editor(|editor, cx| hover_at(editor, Some(hover_point), cx));
        assert!(!cx.editor(|editor, _| editor.hover_state.visible()));

        // After delay, hover should be visible.
        let symbol_range = cx.lsp_range(indoc! {"
            fn test() { «println!»(); }
        "});
        let mut requests =
            cx.handle_request::<lsp::request::HoverRequest, _, _>(move |_, _, _| async move {
                Ok(Some(lsp::Hover {
                    contents: lsp::HoverContents::Markup(lsp::MarkupContent {
                        kind: lsp::MarkupKind::Markdown,
                        value: "some basic docs".to_string(),
                    }),
                    range: Some(symbol_range),
                }))
            });
        cx.background_executor
            .advance_clock(Duration::from_millis(HOVER_DELAY_MILLIS + 100));
        requests.next().await;

        cx.editor(|editor, _| {
            assert!(editor.hover_state.visible());
            assert_eq!(
                editor.hover_state.info_popovers.len(),
                1,
                "Expected exactly one hover but got: {:?}",
                editor.hover_state.info_popovers
            );
            let rendered = editor
                .hover_state
                .info_popovers
                .first()
                .cloned()
                .unwrap()
                .parsed_content;
            assert_eq!(rendered.text, "some basic docs".to_string())
        });

        // Mouse moved with no hover response dismisses
        let hover_point = cx.display_point(indoc! {"
            fn teˇst() { println!(); }
        "});
        let mut request = cx
            .lsp
            .handle_request::<lsp::request::HoverRequest, _, _>(|_, _| async move { Ok(None) });
        cx.update_editor(|editor, cx| hover_at(editor, Some(hover_point), cx));
        cx.background_executor
            .advance_clock(Duration::from_millis(HOVER_DELAY_MILLIS + 100));
        request.next().await;
        cx.editor(|editor, _| {
            assert!(!editor.hover_state.visible());
        });
    }

    #[gpui::test]
    async fn test_keyboard_hover_info_popover(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                hover_provider: Some(lsp::HoverProviderCapability::Simple(true)),
                ..Default::default()
            },
            cx,
        )
        .await;

        // Hover with keyboard has no delay
        cx.set_state(indoc! {"
            fˇn test() { println!(); }
        "});
        cx.update_editor(|editor, cx| hover(editor, &Hover, cx));
        let symbol_range = cx.lsp_range(indoc! {"
            «fn» test() { println!(); }
        "});
        cx.handle_request::<lsp::request::HoverRequest, _, _>(move |_, _, _| async move {
            Ok(Some(lsp::Hover {
                contents: lsp::HoverContents::Markup(lsp::MarkupContent {
                    kind: lsp::MarkupKind::Markdown,
                    value: "some other basic docs".to_string(),
                }),
                range: Some(symbol_range),
            }))
        })
        .next()
        .await;

        cx.condition(|editor, _| editor.hover_state.visible()).await;
        cx.editor(|editor, _| {
            assert_eq!(
                editor.hover_state.info_popovers.len(),
                1,
                "Expected exactly one hover but got: {:?}",
                editor.hover_state.info_popovers
            );
            let rendered = editor
                .hover_state
                .info_popovers
                .first()
                .cloned()
                .unwrap()
                .parsed_content;
            assert_eq!(rendered.text, "some other basic docs".to_string())
        });
    }

    #[gpui::test]
    async fn test_empty_hovers_filtered(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                hover_provider: Some(lsp::HoverProviderCapability::Simple(true)),
                ..Default::default()
            },
            cx,
        )
        .await;

        // Hover with keyboard has no delay
        cx.set_state(indoc! {"
            fˇn test() { println!(); }
        "});
        cx.update_editor(|editor, cx| hover(editor, &Hover, cx));
        let symbol_range = cx.lsp_range(indoc! {"
            «fn» test() { println!(); }
        "});
        cx.handle_request::<lsp::request::HoverRequest, _, _>(move |_, _, _| async move {
            Ok(Some(lsp::Hover {
                contents: lsp::HoverContents::Array(vec![
                    lsp::MarkedString::String("regular text for hover to show".to_string()),
                    lsp::MarkedString::String("".to_string()),
                    lsp::MarkedString::LanguageString(lsp::LanguageString {
                        language: "Rust".to_string(),
                        value: "".to_string(),
                    }),
                ]),
                range: Some(symbol_range),
            }))
        })
        .next()
        .await;

        cx.condition(|editor, _| editor.hover_state.visible()).await;
        cx.editor(|editor, _| {
            assert_eq!(
                editor.hover_state.info_popovers.len(),
                1,
                "Expected exactly one hover but got: {:?}",
                editor.hover_state.info_popovers
            );
            let rendered = editor
                .hover_state
                .info_popovers
                .first()
                .cloned()
                .unwrap()
                .parsed_content;
            assert_eq!(
                rendered.text,
                "regular text for hover to show".to_string(),
                "No empty string hovers should be shown"
            );
        });
    }

    #[gpui::test]
    async fn test_line_ends_trimmed(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                hover_provider: Some(lsp::HoverProviderCapability::Simple(true)),
                ..Default::default()
            },
            cx,
        )
        .await;

        // Hover with keyboard has no delay
        cx.set_state(indoc! {"
            fˇn test() { println!(); }
        "});
        cx.update_editor(|editor, cx| hover(editor, &Hover, cx));
        let symbol_range = cx.lsp_range(indoc! {"
            «fn» test() { println!(); }
        "});

        let code_str = "\nlet hovered_point: Vector2F // size = 8, align = 0x4\n";
        let markdown_string = format!("\n```rust\n{code_str}```");

        let closure_markdown_string = markdown_string.clone();
        cx.handle_request::<lsp::request::HoverRequest, _, _>(move |_, _, _| {
            let future_markdown_string = closure_markdown_string.clone();
            async move {
                Ok(Some(lsp::Hover {
                    contents: lsp::HoverContents::Markup(lsp::MarkupContent {
                        kind: lsp::MarkupKind::Markdown,
                        value: future_markdown_string,
                    }),
                    range: Some(symbol_range),
                }))
            }
        })
        .next()
        .await;

        cx.condition(|editor, _| editor.hover_state.visible()).await;
        cx.editor(|editor, _| {
            assert_eq!(
                editor.hover_state.info_popovers.len(),
                1,
                "Expected exactly one hover but got: {:?}",
                editor.hover_state.info_popovers
            );
            let rendered = editor
                .hover_state
                .info_popovers
                .first()
                .cloned()
                .unwrap()
                .parsed_content;
            assert_eq!(
                rendered.text,
                code_str.trim(),
                "Should not have extra line breaks at end of rendered hover"
            );
        });
    }

    #[gpui::test]
    async fn test_hover_diagnostic_and_info_popovers(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                hover_provider: Some(lsp::HoverProviderCapability::Simple(true)),
                ..Default::default()
            },
            cx,
        )
        .await;

        // Hover with just diagnostic, pops DiagnosticPopover immediately and then
        // info popover once request completes
        cx.set_state(indoc! {"
            fn teˇst() { println!(); }
        "});

        // Send diagnostic to client
        let range = cx.text_anchor_range(indoc! {"
            fn «test»() { println!(); }
        "});
        cx.update_buffer(|buffer, cx| {
            let snapshot = buffer.text_snapshot();
            let set = DiagnosticSet::from_sorted_entries(
                vec![DiagnosticEntry {
                    range,
                    diagnostic: Diagnostic {
                        message: "A test diagnostic message.".to_string(),
                        ..Default::default()
                    },
                }],
                &snapshot,
            );
            buffer.update_diagnostics(LanguageServerId(0), set, cx);
        });

        // Hover pops diagnostic immediately
        cx.update_editor(|editor, cx| hover(editor, &Hover, cx));
        cx.background_executor.run_until_parked();

        cx.editor(|Editor { hover_state, .. }, _| {
            assert!(
                hover_state.diagnostic_popover.is_some() && hover_state.info_popovers.is_empty()
            )
        });

        // Info Popover shows after request responded to
        let range = cx.lsp_range(indoc! {"
            fn «test»() { println!(); }
        "});
        cx.handle_request::<lsp::request::HoverRequest, _, _>(move |_, _, _| async move {
            Ok(Some(lsp::Hover {
                contents: lsp::HoverContents::Markup(lsp::MarkupContent {
                    kind: lsp::MarkupKind::Markdown,
                    value: "some new docs".to_string(),
                }),
                range: Some(range),
            }))
        });
        cx.background_executor
            .advance_clock(Duration::from_millis(HOVER_DELAY_MILLIS + 100));

        cx.background_executor.run_until_parked();
        cx.editor(|Editor { hover_state, .. }, _| {
            hover_state.diagnostic_popover.is_some() && hover_state.info_task.is_some()
        });
    }

    #[gpui::test]
    fn test_render_blocks(cx: &mut gpui::TestAppContext) {
        init_test(cx, |_| {});

        let languages = Arc::new(LanguageRegistry::test(cx.executor()));
        let editor = cx.add_window(|cx| Editor::single_line(cx));
        editor
            .update(cx, |editor, _cx| {
                let style = editor.style.clone().unwrap();

                struct Row {
                    blocks: Vec<HoverBlock>,
                    expected_marked_text: String,
                    expected_styles: Vec<HighlightStyle>,
                }

                let rows = &[
                    // Strong emphasis
                    Row {
                        blocks: vec![HoverBlock {
                            text: "one **two** three".to_string(),
                            kind: HoverBlockKind::Markdown,
                        }],
                        expected_marked_text: "one «two» three".to_string(),
                        expected_styles: vec![HighlightStyle {
                            font_weight: Some(FontWeight::BOLD),
                            ..Default::default()
                        }],
                    },
                    // Links
                    Row {
                        blocks: vec![HoverBlock {
                            text: "one [two](https://the-url) three".to_string(),
                            kind: HoverBlockKind::Markdown,
                        }],
                        expected_marked_text: "one «two» three".to_string(),
                        expected_styles: vec![HighlightStyle {
                            underline: Some(UnderlineStyle {
                                thickness: 1.0.into(),
                                ..Default::default()
                            }),
                            ..Default::default()
                        }],
                    },
                    // Lists
                    Row {
                        blocks: vec![HoverBlock {
                            text: "
                            lists:
                            * one
                                - a
                                - b
                            * two
                                - [c](https://the-url)
                                - d"
                            .unindent(),
                            kind: HoverBlockKind::Markdown,
                        }],
                        expected_marked_text: "
                        lists:
                        - one
                          - a
                          - b
                        - two
                          - «c»
                          - d"
                        .unindent(),
                        expected_styles: vec![HighlightStyle {
                            underline: Some(UnderlineStyle {
                                thickness: 1.0.into(),
                                ..Default::default()
                            }),
                            ..Default::default()
                        }],
                    },
                    // Multi-paragraph list items
                    Row {
                        blocks: vec![HoverBlock {
                            text: "
                            * one two
                              three

                            * four five
                                * six seven
                                  eight

                                  nine
                                * ten
                            * six"
                                .unindent(),
                            kind: HoverBlockKind::Markdown,
                        }],
                        expected_marked_text: "
                        - one two three
                        - four five
                          - six seven eight

                            nine
                          - ten
                        - six"
                            .unindent(),
                        expected_styles: vec![HighlightStyle {
                            underline: Some(UnderlineStyle {
                                thickness: 1.0.into(),
                                ..Default::default()
                            }),
                            ..Default::default()
                        }],
                    },
                ];

                for Row {
                    blocks,
                    expected_marked_text,
                    expected_styles,
                } in &rows[0..]
                {
                    let rendered = smol::block_on(parse_blocks(&blocks, &languages, None));

                    let (expected_text, ranges) = marked_text_ranges(expected_marked_text, false);
                    let expected_highlights = ranges
                        .into_iter()
                        .zip(expected_styles.iter().cloned())
                        .collect::<Vec<_>>();
                    assert_eq!(
                        rendered.text, expected_text,
                        "wrong text for input {blocks:?}"
                    );

                    let rendered_highlights: Vec<_> = rendered
                        .highlights
                        .iter()
                        .filter_map(|(range, highlight)| {
                            let highlight = highlight.to_highlight_style(&style.syntax)?;
                            Some((range.clone(), highlight))
                        })
                        .collect();

                    assert_eq!(
                        rendered_highlights, expected_highlights,
                        "wrong highlights for input {blocks:?}"
                    );
                }
            })
            .unwrap();
    }

    #[gpui::test]
    async fn test_hover_inlay_label_parts(cx: &mut gpui::TestAppContext) {
        init_test(cx, |settings| {
            settings.defaults.inlay_hints = Some(InlayHintSettings {
                enabled: true,
                edit_debounce_ms: 0,
                scroll_debounce_ms: 0,
                show_type_hints: true,
                show_parameter_hints: true,
                show_other_hints: true,
            })
        });

        let mut cx = EditorLspTestContext::new_rust(
            lsp::ServerCapabilities {
                inlay_hint_provider: Some(lsp::OneOf::Right(
                    lsp::InlayHintServerCapabilities::Options(lsp::InlayHintOptions {
                        resolve_provider: Some(true),
                        ..Default::default()
                    }),
                )),
                ..Default::default()
            },
            cx,
        )
        .await;

        cx.set_state(indoc! {"
            struct TestStruct;

            // ==================

            struct TestNewType<T>(T);

            fn main() {
                let variableˇ = TestNewType(TestStruct);
            }
        "});

        let hint_start_offset = cx.ranges(indoc! {"
            struct TestStruct;

            // ==================

            struct TestNewType<T>(T);

            fn main() {
                let variableˇ = TestNewType(TestStruct);
            }
        "})[0]
            .start;
        let hint_position = cx.to_lsp(hint_start_offset);
        let new_type_target_range = cx.lsp_range(indoc! {"
            struct TestStruct;

            // ==================

            struct «TestNewType»<T>(T);

            fn main() {
                let variable = TestNewType(TestStruct);
            }
        "});
        let struct_target_range = cx.lsp_range(indoc! {"
            struct «TestStruct»;

            // ==================

            struct TestNewType<T>(T);

            fn main() {
                let variable = TestNewType(TestStruct);
            }
        "});

        let uri = cx.buffer_lsp_url.clone();
        let new_type_label = "TestNewType";
        let struct_label = "TestStruct";
        let entire_hint_label = ": TestNewType<TestStruct>";
        let closure_uri = uri.clone();
        cx.lsp
            .handle_request::<lsp::request::InlayHintRequest, _, _>(move |params, _| {
                let task_uri = closure_uri.clone();
                async move {
                    assert_eq!(params.text_document.uri, task_uri);
                    Ok(Some(vec![lsp::InlayHint {
                        position: hint_position,
                        label: lsp::InlayHintLabel::LabelParts(vec![lsp::InlayHintLabelPart {
                            value: entire_hint_label.to_string(),
                            ..Default::default()
                        }]),
                        kind: Some(lsp::InlayHintKind::TYPE),
                        text_edits: None,
                        tooltip: None,
                        padding_left: Some(false),
                        padding_right: Some(false),
                        data: None,
                    }]))
                }
            })
            .next()
            .await;
        cx.background_executor.run_until_parked();
        cx.update_editor(|editor, cx| {
            let expected_layers = vec![entire_hint_label.to_string()];
            assert_eq!(expected_layers, cached_hint_labels(editor));
            assert_eq!(expected_layers, visible_hint_labels(editor, cx));
        });

        let inlay_range = cx
            .ranges(indoc! {"
                struct TestStruct;

                // ==================

                struct TestNewType<T>(T);

                fn main() {
                    let variable« »= TestNewType(TestStruct);
                }
        "})
            .get(0)
            .cloned()
            .unwrap();
        let new_type_hint_part_hover_position = cx.update_editor(|editor, cx| {
            let snapshot = editor.snapshot(cx);
            let previous_valid = inlay_range.start.to_display_point(&snapshot);
            let next_valid = inlay_range.end.to_display_point(&snapshot);
            assert_eq!(previous_valid.row(), next_valid.row());
            assert!(previous_valid.column() < next_valid.column());
            let exact_unclipped = DisplayPoint::new(
                previous_valid.row(),
                previous_valid.column()
                    + (entire_hint_label.find(new_type_label).unwrap() + new_type_label.len() / 2)
                        as u32,
            );
            PointForPosition {
                previous_valid,
                next_valid,
                exact_unclipped,
                column_overshoot_after_line_end: 0,
            }
        });
        cx.update_editor(|editor, cx| {
            update_inlay_link_and_hover_points(
                &editor.snapshot(cx),
                new_type_hint_part_hover_position,
                editor,
                true,
                false,
                cx,
            );
        });

        let resolve_closure_uri = uri.clone();
        cx.lsp
            .handle_request::<lsp::request::InlayHintResolveRequest, _, _>(
                move |mut hint_to_resolve, _| {
                    let mut resolved_hint_positions = BTreeSet::new();
                    let task_uri = resolve_closure_uri.clone();
                    async move {
                        let inserted = resolved_hint_positions.insert(hint_to_resolve.position);
                        assert!(inserted, "Hint {hint_to_resolve:?} was resolved twice");

                        // `: TestNewType<TestStruct>`
                        hint_to_resolve.label = lsp::InlayHintLabel::LabelParts(vec![
                            lsp::InlayHintLabelPart {
                                value: ": ".to_string(),
                                ..Default::default()
                            },
                            lsp::InlayHintLabelPart {
                                value: new_type_label.to_string(),
                                location: Some(lsp::Location {
                                    uri: task_uri.clone(),
                                    range: new_type_target_range,
                                }),
                                tooltip: Some(lsp::InlayHintLabelPartTooltip::String(format!(
                                    "A tooltip for `{new_type_label}`"
                                ))),
                                ..Default::default()
                            },
                            lsp::InlayHintLabelPart {
                                value: "<".to_string(),
                                ..Default::default()
                            },
                            lsp::InlayHintLabelPart {
                                value: struct_label.to_string(),
                                location: Some(lsp::Location {
                                    uri: task_uri,
                                    range: struct_target_range,
                                }),
                                tooltip: Some(lsp::InlayHintLabelPartTooltip::MarkupContent(
                                    lsp::MarkupContent {
                                        kind: lsp::MarkupKind::Markdown,
                                        value: format!("A tooltip for `{struct_label}`"),
                                    },
                                )),
                                ..Default::default()
                            },
                            lsp::InlayHintLabelPart {
                                value: ">".to_string(),
                                ..Default::default()
                            },
                        ]);

                        Ok(hint_to_resolve)
                    }
                },
            )
            .next()
            .await;
        cx.background_executor.run_until_parked();

        cx.update_editor(|editor, cx| {
            update_inlay_link_and_hover_points(
                &editor.snapshot(cx),
                new_type_hint_part_hover_position,
                editor,
                true,
                false,
                cx,
            );
        });
        cx.background_executor
            .advance_clock(Duration::from_millis(HOVER_DELAY_MILLIS + 100));
        cx.background_executor.run_until_parked();
        cx.update_editor(|editor, cx| {
            let hover_state = &editor.hover_state;
            assert!(
                hover_state.diagnostic_popover.is_none() && hover_state.info_popovers.len() == 1
            );
            let popover = hover_state.info_popovers.first().cloned().unwrap();
            let buffer_snapshot = editor.buffer().update(cx, |buffer, cx| buffer.snapshot(cx));
            assert_eq!(
                popover.symbol_range,
                RangeInEditor::Inlay(InlayHighlight {
                    inlay: InlayId::Hint(0),
                    inlay_position: buffer_snapshot.anchor_at(inlay_range.start, Bias::Right),
                    range: ": ".len()..": ".len() + new_type_label.len(),
                }),
                "Popover range should match the new type label part"
            );
            assert_eq!(
                popover.parsed_content.text,
                format!("A tooltip for `{new_type_label}`"),
                "Rendered text should not anyhow alter backticks"
            );
        });

        let struct_hint_part_hover_position = cx.update_editor(|editor, cx| {
            let snapshot = editor.snapshot(cx);
            let previous_valid = inlay_range.start.to_display_point(&snapshot);
            let next_valid = inlay_range.end.to_display_point(&snapshot);
            assert_eq!(previous_valid.row(), next_valid.row());
            assert!(previous_valid.column() < next_valid.column());
            let exact_unclipped = DisplayPoint::new(
                previous_valid.row(),
                previous_valid.column()
                    + (entire_hint_label.find(struct_label).unwrap() + struct_label.len() / 2)
                        as u32,
            );
            PointForPosition {
                previous_valid,
                next_valid,
                exact_unclipped,
                column_overshoot_after_line_end: 0,
            }
        });
        cx.update_editor(|editor, cx| {
            update_inlay_link_and_hover_points(
                &editor.snapshot(cx),
                struct_hint_part_hover_position,
                editor,
                true,
                false,
                cx,
            );
        });
        cx.background_executor
            .advance_clock(Duration::from_millis(HOVER_DELAY_MILLIS + 100));
        cx.background_executor.run_until_parked();
        cx.update_editor(|editor, cx| {
            let hover_state = &editor.hover_state;
            assert!(
                hover_state.diagnostic_popover.is_none() && hover_state.info_popovers.len() == 1
            );
            let popover = hover_state.info_popovers.first().cloned().unwrap();
            let buffer_snapshot = editor.buffer().update(cx, |buffer, cx| buffer.snapshot(cx));
            assert_eq!(
                popover.symbol_range,
                RangeInEditor::Inlay(InlayHighlight {
                    inlay: InlayId::Hint(0),
                    inlay_position: buffer_snapshot.anchor_at(inlay_range.start, Bias::Right),
                    range: ": ".len() + new_type_label.len() + "<".len()
                        ..": ".len() + new_type_label.len() + "<".len() + struct_label.len(),
                }),
                "Popover range should match the struct label part"
            );
            assert_eq!(
                popover.parsed_content.text,
                format!("A tooltip for {struct_label}"),
                "Rendered markdown element should remove backticks from text"
            );
        });
    }
}
