import Foundation
import Testing
@testable import Kanban

/// **The card window's ⌘F over the comments pane** — 05-card-window.md ▸ Preview:
///
/// > Edit ▸ Find (⌘F) is find-in-text here — the standard find bar over the focused surface (Preview's
/// > selectable text, the Edit editor, raw source — and the comments pane, where it searches the whole
/// > rendered thread, `.draft` excluded; the composer and an inline comment edit are their own focused
/// > text surfaces with the editor's ordinary find).
///
/// Two claims and therefore two halves: **where the key goes** (a pure routing rule over the pane's
/// focus, `CardWindowFind`), and **what the find does once it is there** (a pure search over the
/// rendered thread plus a session that steps through it, `CommentThreadSearch` / `CommentThreadFind`).
///
/// The thread itself is never `.draft` or `comments/.trash/` here for free — those are excluded from
/// the listing by the loader (`CommentThreadTests`), so a find that searches "the thread" cannot see
/// them by construction.

// MARK: - Fixtures

private func row(_ id: String, _ text: String) -> CommentThreadRow {
    CommentThreadRow(id: ItemID(rawValue: id), text: text)
}

private func comment(_ id: String, body: String) -> Kanban.Comment {
    Kanban.Comment(
        id: ItemID(rawValue: id),
        schema: .valid(1),
        author: .missing,
        created: .missing,
        modified: .missing,
        modifiedBy: .missing,
        attachments: [],
        document: FrontmatterDocument(body: body)
    )
}

// MARK: - Routing

@Suite("Comment find ▸ where ⌘F goes")
struct CardWindowFindRouteTests {

    @Test("A focused comment routes to the thread; a focused authoring surface to its own editor")
    func focusDecides() {
        #expect(CardWindowFind.route(paneFocus: .thread, isThreadFindShowing: false, hasBody: true) == .thread)
        #expect(CardWindowFind.route(paneFocus: .authoring, isThreadFindShowing: false, hasBody: true) == .authoring)
    }

    @Test("With the pane unfocused it is the body's find, exactly as before the pane existed")
    func bodyIsTheDefault() {
        #expect(CardWindowFind.route(paneFocus: nil, isThreadFindShowing: false, hasBody: true) == .body)
        #expect(CardWindowFind.route(paneFocus: nil, isThreadFindShowing: false, hasBody: false) == nil)
    }

    @Test("An open find bar outranks an absent focus — a second ⌘F returns to the search field")
    func theOpenBarKeepsTheKey() {
        // Raising the bar takes the keyboard out of the thread and into the bar's own field, so the
        // pane reports no focus; without this clause the next ⌘F would fall through to the body.
        #expect(CardWindowFind.route(paneFocus: nil, isThreadFindShowing: true, hasBody: true) == .thread)
    }

    @Test("An authoring surface outranks even an open bar — the user is typing in an editor")
    func authoringWins() {
        #expect(CardWindowFind.route(paneFocus: .authoring, isThreadFindShowing: true, hasBody: true) == .authoring)
    }
}

// MARK: - The search

@Suite("Comment find ▸ the search")
struct CommentThreadSearchTests {

    @Test("Matches are in reading order: rows in order, hits within a row left to right")
    func readingOrder() {
        let matches = CommentThreadSearch.matches(
            in: [row(CommentIdent.one, "kestrel and kestrel"), row(CommentIdent.two, "a kestrel")],
            query: "kestrel"
        )
        #expect(matches.count == 3)
        #expect(matches[0] == CommentThreadMatch(comment: ItemID(rawValue: CommentIdent.one), range: NSRange(location: 0, length: 7)))
        #expect(matches[1].comment == ItemID(rawValue: CommentIdent.one))
        #expect(matches[1].range.location == 12)
        #expect(matches[2].comment == ItemID(rawValue: CommentIdent.two))
    }

    @Test("The comparison folds case and diacritics — the board query's own rule")
    func folding() {
        let matches = CommentThreadSearch.matches(in: [row(CommentIdent.one, "A Résumé")], query: "resume")
        #expect(matches.count == 1)
        // The range is in the *unfolded* text, which is what makes the highlight land on what is drawn.
        #expect(matches[0].range == NSRange(location: 2, length: 6))
    }

    @Test("Overlapping occurrences are one hit — NSTextFinder's answer, and the body's ⌘F's")
    func overlapping() {
        // Two finds in one window must not disagree about how many times "aa" occurs in "aaa".
        #expect(CommentThreadSearch.matches(in: [row(CommentIdent.one, "aaa")], query: "aa").count == 1)
        #expect(CommentThreadSearch.matches(in: [row(CommentIdent.one, "aaaa")], query: "aa").count == 2)
    }

    @Test("An empty query finds nothing — the bar opens empty and says nothing")
    func emptyQuery() {
        #expect(CommentThreadSearch.matches(in: [row(CommentIdent.one, "anything")], query: "").isEmpty)
    }

    @Test("Stepping wraps in both directions — which is what makes it one find across rows")
    func stepping() {
        #expect(CommentThreadSearch.step(from: 0, count: 3, forward: true) == 1)
        #expect(CommentThreadSearch.step(from: 2, count: 3, forward: true) == 0)
        #expect(CommentThreadSearch.step(from: 0, count: 3, forward: false) == 2)
        #expect(CommentThreadSearch.step(from: 0, count: 1, forward: true) == 0)
        #expect(CommentThreadSearch.step(from: 0, count: 0, forward: true) == 0)
    }

    @Test("The counter reads as a find bar's does, and says so when there is nothing")
    func status() {
        #expect(CommentThreadSearch.status(index: 0, count: 3, query: "k") == "1 of 3")
        #expect(CommentThreadSearch.status(index: 2, count: 3, query: "k") == "3 of 3")
        #expect(CommentThreadSearch.status(index: 0, count: 0, query: "k") == "No matches")
        #expect(CommentThreadSearch.status(index: 0, count: 0, query: "") == "")
    }
}

// MARK: - The session

@MainActor
@Suite("Comment find ▸ the session")
struct CommentThreadFindTests {

    private let pointSize: CGFloat = 13

    @Test("⌘F raises the bar and asks for the keyboard, every time")
    func invoking() {
        let find = CommentThreadFind()
        #expect(!find.isShowing)

        find.invoke()
        #expect(find.isShowing)
        #expect(find.focusRequests == 1)

        // A second press is a re-focus, not a dismissal — `FindCommand`'s "focus, not toggle" rule.
        find.invoke()
        #expect(find.isShowing)
        #expect(find.focusRequests == 2)
    }

    @Test("Done keeps the query — re-opening lands on the search the user was running")
    func dismissKeepsTheQuery() {
        let find = CommentThreadFind()
        find.invoke()
        find.setThread([comment(CommentIdent.one, body: "kestrel")], pointSize: 13)
        find.query = "kestrel"
        #expect(find.matches(in: ItemID(rawValue: CommentIdent.one)).count == 1)

        find.dismiss()
        #expect(!find.isShowing)
        #expect(find.query == "kestrel")
        // The marks come off the thread with the bar — a dismissed find must not leave a highlighted
        // thread behind, even though the search itself is remembered.
        #expect(find.matches(in: ItemID(rawValue: CommentIdent.one)).isEmpty)
        #expect(find.currentMatch == nil)
    }

    @Test("It searches the *rendered* thread — markup is not what the reader sees, so it is not searched")
    func searchesRenderedText() {
        let find = CommentThreadFind()
        find.setThread([comment(CommentIdent.one, body: "A **bold** remark")], pointSize: pointSize)

        find.query = "bold"
        #expect(find.matches.count == 1)
        // The asterisks are markup the renderer consumed; a user looking at the row cannot see them.
        find.query = "**bold**"
        #expect(find.matches.isEmpty)
    }

    @Test("Every comment is searched, mounted or not — the rows come from the thread, not the views")
    func spansTheWholeThread() {
        let find = CommentThreadFind()
        find.invoke()
        find.setThread(
            [
                comment(CommentIdent.one, body: "first kestrel"),
                comment(CommentIdent.two, body: "nothing here"),
                comment(CommentIdent.three, body: "second kestrel")
            ],
            pointSize: pointSize
        )
        find.query = "kestrel"

        #expect(find.matches.count == 2)
        #expect(find.matches.map(\.comment) == [ItemID(rawValue: CommentIdent.one), ItemID(rawValue: CommentIdent.three)])
        #expect(find.matches(in: ItemID(rawValue: CommentIdent.two)).isEmpty)
        #expect(find.matches(in: ItemID(rawValue: CommentIdent.three)).count == 1)
    }

    @Test("Next crosses rows, and wraps — one find, not one per comment")
    func steppingCrossesRows() {
        let find = CommentThreadFind()
        find.invoke()
        find.setThread(
            [comment(CommentIdent.one, body: "kestrel"), comment(CommentIdent.two, body: "kestrel")],
            pointSize: pointSize
        )
        find.query = "kestrel"

        #expect(find.currentMatch?.comment == ItemID(rawValue: CommentIdent.one))
        find.step(forward: true)
        #expect(find.currentMatch?.comment == ItemID(rawValue: CommentIdent.two))
        find.step(forward: true)
        #expect(find.currentMatch?.comment == ItemID(rawValue: CommentIdent.one))
        find.step(forward: false)
        #expect(find.currentMatch?.comment == ItemID(rawValue: CommentIdent.two))
    }

    @Test("A new query is a new search, so it starts at the first hit")
    func queryChangeResets() {
        let find = CommentThreadFind()
        find.setThread(
            [comment(CommentIdent.one, body: "kestrel kestrel kestrel")],
            pointSize: pointSize
        )
        find.query = "kestrel"
        find.step(forward: true)
        find.step(forward: true)
        #expect(find.status == "3 of 3")

        find.query = "kestre"
        #expect(find.status == "1 of 3")
    }

    @Test("A thread re-read under an open bar keeps the user's place")
    func reloadPreservesPosition() {
        let find = CommentThreadFind()
        find.setThread(
            [comment(CommentIdent.one, body: "kestrel"), comment(CommentIdent.two, body: "kestrel")],
            pointSize: pointSize
        )
        find.query = "kestrel"
        find.step(forward: true)
        #expect(find.status == "2 of 2")

        // An agent files a third comment while the user is stepping through the search.
        find.setThread(
            [
                comment(CommentIdent.one, body: "kestrel"),
                comment(CommentIdent.two, body: "kestrel"),
                comment(CommentIdent.three, body: "kestrel")
            ],
            pointSize: pointSize
        )
        #expect(find.status == "2 of 3")
    }

    @Test("A re-read that removes the matches clamps rather than pointing past the end")
    func reloadClamps() {
        let find = CommentThreadFind()
        find.invoke()
        find.setThread([comment(CommentIdent.one, body: "kestrel kestrel")], pointSize: pointSize)
        find.query = "kestrel"
        find.step(forward: true)

        find.setThread([comment(CommentIdent.one, body: "a falcon instead")], pointSize: pointSize)
        #expect(find.matches.isEmpty)
        #expect(find.currentMatch == nil)
        #expect(find.status == "No matches")
    }
}

// MARK: - The pane's routing, end to end

@MainActor
@Suite("Comment find ▸ the pane's focus")
struct CommentPaneFindRoutingTests {

    @Test("A focused comment sends ⌘F to the thread's bar")
    func threadFocusRaisesTheBar() {
        let comments = CardComments()
        comments.focusEntered(.thread)

        #expect(comments.invokeFind(hasBody: true))
        #expect(comments.find.isShowing)
    }

    @Test("A focused authoring surface sends ⌘F to that editor's own find bar")
    func authoringFocusRunsTheEditorsFind() {
        let comments = CardComments()
        var editorFinds = 0
        comments.focusEntered(.authoring) { editorFinds += 1 }

        #expect(comments.invokeFind(hasBody: true))
        #expect(editorFinds == 1)
        #expect(!comments.find.isShowing)
    }

    @Test("With nothing in the pane focused, ⌘F is declined and the body keeps it")
    func unfocusedDeclines() {
        let comments = CardComments()
        #expect(!comments.invokeFind(hasBody: true))
        #expect(!comments.find.isShowing)
    }

    @Test("A late resignation from a surface that no longer holds focus is ignored")
    func lateResignationIsIgnored() {
        // AppKit resigns the outgoing responder before the incoming one becomes first, but the
        // guard covers the case where it does not: clicking from a comment into the composer must
        // not leave the pane reporting no focus at all.
        let comments = CardComments()
        comments.focusEntered(.thread)
        comments.focusEntered(.authoring) {}
        comments.focusLeft(.thread)

        #expect(comments.paneFocus == .authoring)
    }

    @Test("Losing focus for real clears it, and the editor's find goes with it")
    func focusLeftClears() {
        let comments = CardComments()
        comments.focusEntered(.authoring) {}
        comments.focusLeft(.authoring)

        #expect(comments.paneFocus == nil)
        #expect(!comments.invokeFind(hasBody: true))
    }

    @Test("Find Next and Find Previous validate on the thread's bar alone")
    func steppingRowsValidate() {
        // The two other finds in this window are `NSTextFinder`'s, and `NSTextView` answers ⌘G through
        // the responder chain — an enabled menu item would fire first and break the stepping it exists
        // to provide (`FindSteppingCommands`).
        #expect(!FindSteppingCommands.isEnabled(nil))

        let comments = CardComments()
        #expect(!FindSteppingCommands.isEnabled(comments))

        comments.focusEntered(.thread)
        _ = comments.invokeFind(hasBody: true)
        #expect(FindSteppingCommands.isEnabled(comments))

        comments.find.dismiss()
        #expect(!FindSteppingCommands.isEnabled(comments))
    }
}