import Testing
@testable import Kanban

/// `caretChordsYield(boardInfo:boardSettings:search:)` — 04-interactions.md ▸ Grammar's caret-chords
/// rule as one expression, and `BoardCommands.swift`'s single seam for it: Board ▸ Move Left/Move
/// Right ⌘←/⌘→ and the lane-width pair ⌥⌘←/⌥⌘→ disable via menu validation whenever *any* text
/// control has keyboard focus, because ⌘←/⌘→ are the standard line-start/end caret chords and an
/// enabled key equivalent fires before a field ever sees the key.
///
/// The function reads exactly three flags and nothing else, so every test here constructs
/// `BoardInfoPresentation`, `BoardSettingsPresentation` and `BoardSearchPresentation` directly rather
/// than through a `BoardStore` — a fixture that stood up a board would be exercising machinery this
/// seam never touches.
@MainActor
@Suite("caretChordsYield ▸ the caret-chords rule")
struct CaretChordTests {

    // MARK: Scopeless windows

    @Test("A card window publishes neither presentation, and the chords stay enabled")
    func scopelessWindowDoesNotYield() {
        // "Card-window fields need nothing: those windows never publish a boardStore, so both items
        // are already scopeless there" (caretChordsYield's doc comment) — nil/nil is that window's
        // steady state, not a corner case.
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: nil) == false)
    }

    // MARK: The board popover, alone

    @Test("The board popover open yields; closed, it does not")
    func popoverPresence() {
        let boardInfo = BoardInfoPresentation()
        #expect(caretChordsYield(boardInfo: boardInfo, boardSettings: nil, search: nil) == false, "closed by default")

        boardInfo.isPresented = true
        #expect(caretChordsYield(boardInfo: boardInfo, boardSettings: nil, search: nil) == true)

        boardInfo.isPresented = false
        #expect(caretChordsYield(boardInfo: boardInfo, boardSettings: nil, search: nil) == false, "closing re-enables the chords")
    }

    // MARK: The settings sheet, alone

    @Test("The settings sheet open yields; closed, it does not")
    func settingsSheetPresence() {
        // The sheet joined this seam with the 2026-07-31 popover/sheet split: it is where the branch
        // name field and the commit-identity fields live now, so the surface that used to be covered
        // by "the popover is open" has to be covered by "the sheet is up" as well.
        let settings = BoardSettingsPresentation()
        #expect(caretChordsYield(boardInfo: nil, boardSettings: settings, search: nil) == false, "closed by default")

        settings.isPresented = true
        #expect(caretChordsYield(boardInfo: nil, boardSettings: settings, search: nil) == true)

        settings.isPresented = false
        #expect(
            caretChordsYield(boardInfo: nil, boardSettings: settings, search: nil) == false,
            "dismissing re-enables the chords"
        )
    }

    @Test("The sheet's own reachability is not this seam's question — a presented sheet yields either way")
    func presentationRatherThanReachability() {
        // `isReachable` gates the two *doors* (`BoardSettingsAvailability`); this function reads the
        // flag that says a sheet is on screen. A presentation left unadopted reads free-tier and
        // therefore unreachable, and if something ever put its flag up anyway the chords must still
        // yield — what a caret chord competes with is a field that exists, not a tier.
        let settings = BoardSettingsPresentation()
        #expect(settings.isReachable == false, "unadopted reads as the free tier")

        settings.isPresented = true
        #expect(caretChordsYield(boardInfo: nil, boardSettings: settings, search: nil) == true)
    }

    // MARK: The search field, alone

    @Test("The search field focused yields; unfocused, it does not")
    func searchFocus() {
        let search = BoardSearchPresentation()
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: search) == false, "unfocused by default")

        search.isFocused = true
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: search) == true)

        search.isFocused = false
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: search) == false, "losing focus re-enables the chords")
    }

    // MARK: Both surfaces together

    @Test("Either surface active is enough to yield; both absent-or-inert is the only false")
    func eitherSurfaceIsSufficient() {
        let closedInfo = BoardInfoPresentation()
        let openInfo = BoardInfoPresentation()
        openInfo.isPresented = true
        let unfocusedSearch = BoardSearchPresentation()
        let focusedSearch = BoardSearchPresentation()
        focusedSearch.isFocused = true

        // One side published and inert, the other absent (the still-loading-window shape): false.
        #expect(caretChordsYield(boardInfo: closedInfo, boardSettings: nil, search: nil) == false)
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: unfocusedSearch) == false)

        // One side published and active, the other absent: true.
        #expect(caretChordsYield(boardInfo: openInfo, boardSettings: nil, search: nil) == true)
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: focusedSearch) == true)

        // Both published, both inert: false — the popover being open at all and the field holding
        // focus are each read independently, so neither's mere presence counts on its own.
        #expect(caretChordsYield(boardInfo: closedInfo, boardSettings: nil, search: unfocusedSearch) == false)

        // Both published, one or both active: true. This is an `||`, not an `&&` — one live text
        // surface is enough to send the chords to it, whatever the other surface is doing.
        #expect(caretChordsYield(boardInfo: openInfo, boardSettings: nil, search: unfocusedSearch) == true)
        #expect(caretChordsYield(boardInfo: closedInfo, boardSettings: nil, search: focusedSearch) == true)
        #expect(caretChordsYield(boardInfo: openInfo, boardSettings: nil, search: focusedSearch) == true)

        // And the third surface composes the same way — inert beside two inert siblings, sufficient
        // beside them when it is up.
        let closedSheet = BoardSettingsPresentation()
        let openSheet = BoardSettingsPresentation()
        openSheet.isPresented = true

        #expect(caretChordsYield(boardInfo: closedInfo, boardSettings: closedSheet, search: unfocusedSearch) == false)
        #expect(caretChordsYield(boardInfo: closedInfo, boardSettings: openSheet, search: unfocusedSearch) == true)
        #expect(caretChordsYield(boardInfo: openInfo, boardSettings: openSheet, search: focusedSearch) == true)
    }

    // MARK: Inline editors are a different seam

    @Test("An inline title editor is not this seam's job — acceptsBoardMutations covers it")
    func inlineEditingIsAForeignConcern() {
        // Inline title editors are the caret-chords rule's *first* named surface (the doc comment's
        // list), but they are answered through `acceptsBoardMutations`, not here: `MoveLaneCommands`
        // and `LaneWidthCommands` each disable on `yieldsCaretChords || <the acceptsBoardMutations
        // check>`, so a rename or a new-card placeholder already closes the items through that other
        // half of the `||` before this function is ever asked. Pinning `caretChordsYield`'s own
        // independence from `isEditingInline` is what keeps that split honest.
        let transient = TransientBoardState()
        transient.beginRename(of: ItemID(rawValue: "11111111-1111-4111-8111-111111111111"), currentTitle: "Card")
        #expect(transient.isEditingInline == true, "the rename editor is open")

        // No board popover, no search focus — caretChordsYield answers false regardless of the open
        // editor above, because it never reads isEditingInline at all.
        #expect(caretChordsYield(boardInfo: nil, boardSettings: nil, search: nil) == false)
    }
}