package main

import (
	"strings"
	"testing"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/charmbracelet/x/ansi"
	"github.com/muesli/termenv"
)

func TestDiffletExpressionsAndFramesHaveStableCellDimensions(t *testing.T) {
	expressions := []DiffletExpression{
		DiffletIdle, DiffletFocused, DiffletHappy, DiffletApproved,
		DiffletSurprised, DiffletConcerned, DiffletConfused, DiffletSad,
		DiffletAnnoyed, DiffletError, DiffletSleeping, DiffletCurious,
	}
	for _, expression := range expressions {
		face := diffletFaces[expression]
		if width := lipgloss.Width(face); width != 3 {
			t.Errorf("%s face width = %d, want 3: %q", expression, width, face)
		}
		lines := (DiffletFrame{Expression: expression}).lines()
		if len(lines) != diffletHeight {
			t.Fatalf("%s has %d lines, want %d", expression, len(lines), diffletHeight)
		}
		for row, line := range lines {
			if width := lipgloss.Width(line); width != diffletWidth {
				t.Errorf("%s row %d width = %d, want %d: %q",
					expression, row, width, diffletWidth, line)
			}
		}
	}
}

func TestDiffletCanonicalFramePreservesGlyphsAndSpacing(t *testing.T) {
	got := (DiffletFrame{Expression: DiffletIdle}).lines()
	want := []string{
		"▄███████▄",
		"█+ •_• -█",
		"▀███████▀",
		" ▝     ▘ ",
	}
	if strings.Join(got, "\n") != strings.Join(want, "\n") {
		t.Fatalf("canonical frame:\n%q\nwant:\n%q", got, want)
	}
}

func TestDiffletStylesOnlyDiffSigns(t *testing.T) {
	previousProfile := lipgloss.ColorProfile()
	lipgloss.SetColorProfile(termenv.TrueColor)
	t.Cleanup(func() { lipgloss.SetColorProfile(previousProfile) })
	previousOK, previousBad := okStyle, badStyle
	okStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("#00ff00"))
	badStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("#ff0000"))
	t.Cleanup(func() { okStyle, badStyle = previousOK, previousBad })

	rendered := (DiffletFrame{Expression: DiffletIdle}).render()
	wantMiddle := "█" + okStyle.Render("+") + " •_• " + badStyle.Render("-") + "█"
	if rendered[1] != wantMiddle {
		t.Fatalf("middle row = %q, want %q", rendered[1], wantMiddle)
	}
	if ansi.Strip(strings.Join(rendered, "\n")) !=
		strings.Join((DiffletFrame{Expression: DiffletIdle}).lines(), "\n") {
		t.Fatal("styling changed Difflet glyphs or spacing")
	}
	for _, row := range []int{0, 2, 3} {
		if strings.Contains(rendered[row], "\x1b[") {
			t.Fatalf("row %d unexpectedly styled: %q", row, rendered[row])
		}
	}
}

func TestDiffletEnabledSitsRightOfWrappingHeader(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "owner", "repository", false, 10, 10,
		AppSettings{Mascot: true},
	)
	updated, _ := app.Update(tea.WindowSizeMsg{Width: 24, Height: 12})
	app = updated.(App)
	rendered := strings.Split(app.View(), "\n")
	if len(rendered) < diffletHeight+2 {
		t.Fatalf("rendered rows = %d, want at least %d", len(rendered), diffletHeight+2)
	}

	headerWidth := diffletHeaderWidth(app.width)
	content := app
	content.headerWidth = headerWidth
	_, _, ok := splitHeader(content.viewContent())
	if !ok {
		t.Fatal("test view did not expose a header")
	}
	wantMascotLeft := headerWidth + diffletGap
	for row, mascotLine := range (DiffletFrame{Expression: DiffletIdle}).lines() {
		plain := ansi.Strip(rendered[row])
		if !strings.Contains(plain, strings.TrimRight(mascotLine, " ")) {
			t.Fatalf("mascot row %d is not visible: %q", row, plain)
		}
		left := strings.Index(plain, strings.TrimRight(mascotLine, " "))
		if left != wantMascotLeft {
			t.Fatalf("mascot row %d starts at %d, want adjacent position %d",
				row, left, wantMascotLeft)
		}
	}
	blankRow := -1
	var headerText strings.Builder
	for row := 0; row < len(rendered); row++ {
		line := rendered[row]
		plain := ansi.Strip(line)
		if strings.TrimSpace(plain) == "" {
			blankRow = row
			break
		}
		headerText.WriteString(strings.TrimSpace(
			ansi.Cut(plain, 0, wantMascotLeft-diffletGap),
		))
	}
	normalizedHeader := strings.ReplaceAll(headerText.String(), " ", "")
	for _, information := range []string{"diple", "owner/repository", "assignedtoyou"} {
		if !strings.Contains(normalizedHeader, information) {
			t.Fatalf("wrapped header does not contain %q: %s", information, normalizedHeader)
		}
	}
	if blankRow < diffletHeight {
		t.Fatalf("blank row = %d, want at or below mascot row %d",
			blankRow, diffletHeight)
	}
}

func TestDiffletIsCenteredAtNormalWidths(t *testing.T) {
	mascot := (DiffletFrame{Expression: DiffletIdle}).lines()
	const width = 40
	headerWidth := diffletHeaderWidth(width)
	rendered := strings.Split(
		renderHeaderWithDifflet([]string{"diple"}, mascot, width, headerWidth, diffletGap),
		"\n",
	)
	for row, line := range rendered[:diffletHeight] {
		mascotText := strings.TrimRight(mascot[row], " ")
		wantLeft := (width - diffletWidth) / 2
		if left := strings.Index(ansi.Strip(line), mascotText); left != wantLeft {
			t.Fatalf("row %d mascot starts at %d, want %d: %q",
				row, left, wantLeft, line)
		}
	}
}

func TestDiffletLongHeaderKeepsMascotCentered(t *testing.T) {
	const width = 80
	headerWidth := diffletHeaderWidth(width)
	if headerWidth != 33 {
		t.Fatalf("header width = %d, want 33", headerWidth)
	}
	mascot := (DiffletFrame{Expression: DiffletIdle}).lines()
	rendered := strings.Split(
		renderHeaderWithDifflet(
			[]string{strings.Repeat("x", headerWidth)},
			mascot,
			width,
			headerWidth,
			diffletGap,
		),
		"\n",
	)
	mascotLeft := strings.Index(ansi.Strip(rendered[0]), strings.TrimRight(mascot[0], " "))
	if mascotLeft != headerWidth+diffletGap {
		t.Fatalf("mascot starts at %d, want %d", mascotLeft, headerWidth+diffletGap)
	}
	if mascotLeft != (width-diffletWidth)/2 {
		t.Fatalf("mascot starts at %d, want centered position %d",
			mascotLeft, (width-diffletWidth)/2)
	}
}

func TestDiffletFallsBackToSmallRightPadding(t *testing.T) {
	const width = 24
	headerWidth := diffletHeaderWidth(width)
	mascotLeft := headerWidth + diffletGap
	if rightPadding := width - mascotLeft - diffletWidth; rightPadding != 1 {
		t.Fatalf("fallback right padding = %d, want 1", rightPadding)
	}
}

func TestDiffletDisabledPreservesViewExactly(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "", "", false, 10, 10,
		AppSettings{MascotExpressive: true, MascotAnimated: true},
	)
	updated, _ := app.Update(tea.WindowSizeMsg{Width: 20, Height: 12})
	app = updated.(App)
	got := app.View()
	want := app.viewContent()
	if got != want {
		t.Fatalf("disabled mascot changed rendered view:\ngot:\n%q\nwant:\n%q", got, want)
	}
}

func TestDiffletDashboardIsCenteredBesideMetadata(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "owner", "repository", false, 10, 10,
		AppSettings{Mascot: true},
	)
	app.screen = dashboardScreen
	app.loading = false
	app.details = PRDetails{
		PullRequest: PullRequest{
			RepoWithOwner: "owner/repository", Number: 42,
			Title: "A useful title", Author: "alice",
		},
		HeadRef: "feature", BaseRef: "main",
	}
	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
	app = updated.(App)

	rendered := strings.Split(app.View(), "\n")
	headerHeight := len(app.dashboardHeaderLines())
	if strings.TrimSpace(ansi.Strip(rendered[headerHeight])) == "" {
		t.Fatal("dashboard left a blank row between its title and metadata")
	}
	for row, mascotLine := range (DiffletFrame{Expression: DiffletIdle}).lines() {
		plain := ansi.Strip(rendered[headerHeight+row])
		mascotText := strings.TrimRight(mascotLine, " ")
		mascotIndex := strings.Index(plain, mascotText)
		left := -1
		if mascotIndex >= 0 {
			left = lipgloss.Width(plain[:mascotIndex])
		}
		if left != (app.width-diffletWidth)/2 {
			t.Fatalf("row %d mascot starts at %d, want centered position %d: %q",
				row, left, (app.width-diffletWidth)/2, plain)
		}
	}
	for row, label := range []string{"author", "branches", "review"} {
		if !strings.Contains(ansi.Strip(rendered[headerHeight+row]), label) {
			t.Fatalf("dashboard row %d does not place %q beside mascot: %q",
				row, label, ansi.Strip(rendered[headerHeight+row]))
		}
	}
}

func TestDiffletIsHiddenInEditorAndPopups(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "owner", "repository", false, 10, 10,
		AppSettings{Mascot: true},
	)
	app.screen = dashboardScreen
	app.loading = false
	app.details = PRDetails{PullRequest: PullRequest{
		RepoWithOwner: "owner/repository", Number: 42, Title: "Title",
	}}
	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
	app = updated.(App)

	for _, mode := range []writeMode{writePREdit, writeReplyConfirm} {
		app.writeMode = mode
		if got, want := app.View(), app.viewContent(); got != want {
			t.Fatalf("write mode %d changed by enabled mascot:\ngot:\n%q\nwant:\n%q",
				mode, got, want)
		}
		if strings.Contains(ansi.Strip(app.View()), "▄███████▄") {
			t.Fatalf("write mode %d displayed the mascot", mode)
		}
	}
	app.writeMode = writeNone
	app.helpVisible = true
	if got, want := app.View(), app.viewContent(); got != want {
		t.Fatalf("help popup changed by enabled mascot:\ngot:\n%q\nwant:\n%q", got, want)
	}
}

func TestDiffletEnabledEditorCanRevealLastDescriptionRow(t *testing.T) {
	app := NewAppWithSettings(
		&recordingPRService{}, "owner", "repository", false, 10, 10,
		AppSettings{Mascot: true},
	)
	app.screen = dashboardScreen
	app.loading = false
	app.width, app.height = 50, 12
	app.details = PRDetails{
		PullRequest: PullRequest{
			ID: "pr", RepoWithOwner: "owner/repository", Number: 42,
			Title: "Title",
		},
		BaseRef: "main",
		Body:    strings.Repeat("description row\n", 20) + "LAST DESCRIPTION ROW",
		Permissions: ViewerPermissions{
			CanUpdatePR: true,
		},
	}
	app.startPREdit()
	app.prEditEditors[prEditBodyField].Cursor =
		len([]rune(app.prEditEditors[prEditBodyField].Text))
	app.ensurePREditCursorVisible()

	rendered := ansi.Strip(app.View())
	if !strings.Contains(rendered, "LAST DESCRIPTION ROW") {
		t.Fatalf("last description row is outside the editor viewport:\n%s", rendered)
	}
	if strings.Contains(rendered, "▄███████▄") {
		t.Fatal("editor displayed the mascot instead of using its full height")
	}
}

func TestDashboardDiffletRemainsCenteredAtNarrowWidths(t *testing.T) {
	mascot := (DiffletFrame{Expression: DiffletIdle}).lines()
	metadata := []string{"author", "branches", "review", "checks"}
	for width := diffletWidth; width < 20; width++ {
		rendered := renderDashboardMetadataWithDifflet(metadata, mascot, width)
		for row, mascotLine := range mascot {
			mascotText := strings.TrimRight(mascotLine, " ")
			var mascotRow string
			for _, line := range rendered {
				if strings.Contains(line, mascotText) {
					mascotRow = line
					break
				}
			}
			index := strings.Index(mascotRow, mascotText)
			left := -1
			if index >= 0 {
				left = lipgloss.Width(mascotRow[:index])
			}
			if want := max(0, (width-diffletWidth)/2); left != want {
				t.Fatalf("width %d row %d mascot starts at %d, want %d: %q",
					width, row, left, want, mascotRow)
			}
		}
	}
}

func TestDashboardLoadingDiffletIsCentered(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "owner", "repository", false, 10, 10,
		AppSettings{Mascot: true},
	)
	app.screen = dashboardScreen
	app.loading = true
	app.details = PRDetails{PullRequest: PullRequest{
		RepoWithOwner: "owner/repository", Number: 42, Title: "Title",
	}}
	updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
	app = updated.(App)

	rendered := strings.Split(app.View(), "\n")
	mascotLine := strings.TrimRight((DiffletFrame{Expression: DiffletIdle}).lines()[0], " ")
	for row, line := range rendered {
		plain := ansi.Strip(line)
		index := strings.Index(plain, mascotLine)
		if index < 0 {
			continue
		}
		if left := lipgloss.Width(plain[:index]); left != (app.width-diffletWidth)/2 {
			t.Fatalf("loading mascot starts at %d, want %d: %q",
				left, (app.width-diffletWidth)/2, plain)
		}
		if row != len(app.dashboardHeaderLines()) {
			t.Fatalf("loading mascot begins on row %d, want %d",
				row, len(app.dashboardHeaderLines()))
		}
		return
	}
	t.Fatal("loading dashboard did not display the mascot")
}

func TestDiffletHeaderMeasurementMatchesRenderedHeader(t *testing.T) {
	tests := []struct {
		name   string
		screen screen
	}{
		{name: "picker", screen: prScreen},
		{name: "dashboard", screen: dashboardScreen},
		{name: "threads", screen: threadScreen},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			app := NewAppWithSettings(
				&recordingService{}, "owner", "repository", false, 10, 10,
				AppSettings{Mascot: true},
			)
			app.screen = test.screen
			app.details = PRDetails{PullRequest: PullRequest{
				Owner: "owner", Repository: "repository",
				RepoWithOwner: "owner/repository", Number: 42,
				Title: "A pull request with a useful title",
			}}
			updated, _ := app.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
			app = updated.(App)
			app.headerWidth = diffletHeaderWidth(app.width)

			measured, ok := app.diffletHeaderLineCount()
			if !ok {
				t.Fatal("normal screen did not expose measurable header lines")
			}
			renderedHeader, _, ok := splitHeader(app.viewContent())
			if !ok {
				t.Fatal("rendered normal screen did not expose a header")
			}
			if measured != len(renderedHeader) {
				t.Fatalf("measured header lines = %d, rendered = %d",
					measured, len(renderedHeader))
			}
		})
	}
}

func TestDiffletKeepsCompleteFrameAtNarrowPhysicalMinimum(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "", "", false, 10, 10,
		AppSettings{Mascot: true},
	)
	updated, _ := app.Update(tea.WindowSizeMsg{Width: diffletWidth, Height: 12})
	app = updated.(App)
	rendered := strings.Split(app.View(), "\n")
	for row, mascotLine := range (DiffletFrame{Expression: DiffletIdle}).lines() {
		if got := ansi.Strip(rendered[row]); got != mascotLine {
			t.Fatalf("mascot row %d = %q, want %q", row, got, mascotLine)
		}
	}
	headerBelowMascot := ansi.Strip(strings.Join(rendered[diffletHeight:], "\n"))
	normalizedHeader := strings.NewReplacer("\n", "", " ", "").Replace(headerBelowMascot)
	if !strings.Contains(normalizedHeader, "diple") {
		t.Fatalf("header did not wrap below complete mascot: %q", headerBelowMascot)
	}
}

func TestDiffletStopsTicksBelowPhysicalMinimum(t *testing.T) {
	app := NewAppWithSettings(
		&recordingService{}, "", "", false, 10, 10,
		AppSettings{Mascot: true, MascotAnimated: true},
	)
	if command := app.difflet.start(); command != nil {
		t.Fatal("hidden startup mascot scheduled a tick")
	}
	updated, command := app.Update(tea.WindowSizeMsg{Width: 12, Height: 12})
	app = updated.(App)
	if command == nil {
		t.Fatal("visible animated mascot did not schedule a tick")
	}
	generation := app.difflet.generation
	updated, command = app.Update(tea.WindowSizeMsg{Width: 8, Height: 12})
	app = updated.(App)
	if command != nil {
		t.Fatal("mascot below its nine-cell minimum scheduled a tick")
	}
	if app.difflet.visible {
		t.Fatal("mascot below its nine-cell minimum remained visible")
	}
	updated, command = app.Update(diffletTickMsg{generation: generation})
	app = updated.(App)
	if command != nil || app.difflet.visible {
		t.Fatal("stale tick restarted hidden mascot")
	}
}

func TestDiffletStaticOptionsSelectFinalSafeExpression(t *testing.T) {
	model := newDifflet(true, false, false)
	if command := model.setState(diffletSuccess); command != nil {
		t.Fatal("animation-disabled Difflet scheduled a tick")
	}
	if model.expression != DiffletHappy {
		t.Fatalf("static success = %s, want %s", model.expression, DiffletHappy)
	}
	if command := model.setState(diffletRecoverableError); command != nil {
		t.Fatal("non-expressive Difflet scheduled an error animation")
	}
	if model.expression != DiffletConcerned {
		t.Fatalf("non-expressive error = %s, want %s", model.expression, DiffletConcerned)
	}
	model.setState(diffletFatalError)
	if model.expression != DiffletError {
		t.Fatalf("non-expressive fatal error = %s, want %s", model.expression, DiffletError)
	}
}

func TestDiffletFocusedStateDoesNotLoop(t *testing.T) {
	model := newDifflet(true, true, true)
	if command := model.setState(diffletFocused); command != nil {
		t.Fatal("focused state scheduled continuous animation")
	}
	if model.expression != DiffletFocused || len(model.animation.frames) != 0 {
		t.Fatalf("focused state = expression %s, animation %#v",
			model.expression, model.animation)
	}
}

func TestDiffletLoadingFootShuffleSequence(t *testing.T) {
	model := newDifflet(true, false, true)
	if command := model.setState(diffletLoading); command == nil {
		t.Fatal("loading animation did not schedule a tick")
	}
	want := []string{" ▝     ▘ ", "  ▝   ▘  ", "   ▝ ▘   ", "  ▝   ▘  "}
	for index, feet := range want {
		if got := model.frameLines()[3]; got != feet {
			t.Fatalf("loading frame %d feet = %q, want %q", index, got, feet)
		}
		if index < len(want)-1 {
			if command := model.update(diffletTickMsg{generation: model.generation}); command == nil {
				t.Fatalf("loading frame %d stopped looping", index)
			}
		}
	}
}

func TestDiffletOneShotStopsAndSettles(t *testing.T) {
	model := newDifflet(true, true, true)
	model.setState(diffletSuccess)
	for index := 0; index < 3; index++ {
		if command := model.update(diffletTickMsg{generation: model.generation}); command == nil {
			t.Fatalf("success animation stopped at frame %d", index)
		}
	}
	if command := model.update(diffletTickMsg{generation: model.generation}); command != nil {
		t.Fatal("completed success animation scheduled another tick")
	}
	if len(model.animation.frames) != 0 || model.expression != DiffletHappy {
		t.Fatalf("success settled with animation=%#v expression=%s",
			model.animation, model.expression)
	}
}

func TestDiffletLoopStopsOnStateChangeAndRejectsStaleTick(t *testing.T) {
	model := newDifflet(true, true, true)
	model.setState(diffletLoading)
	oldGeneration := model.generation
	if command := model.update(diffletTickMsg{generation: oldGeneration}); command == nil {
		t.Fatal("loading animation did not continue")
	}
	model.setState(diffletConcerned)
	if command := model.update(diffletTickMsg{generation: oldGeneration}); command != nil {
		t.Fatal("stale tick scheduled another tick")
	}
	if model.expression != DiffletConcerned || model.frame != 0 {
		t.Fatalf("stale tick changed newer state: expression=%s frame=%d",
			model.expression, model.frame)
	}
}