package ui

import (
	"strings"
	"testing"

	"github.com/charmbracelet/lipgloss"
)

// Every registered theme must carry valid #RRGGBB tokens — guards against a
// typo in the ported palettes.
func TestThemesHaveValidHex(t *testing.T) {
	if len(themes) != 6 {
		t.Fatalf("expected 6 themes, got %d", len(themes))
	}
	valid := func(c string) bool {
		if len(c) != 7 || c[0] != '#' {
			return false
		}
		_, ok := strings.CutPrefix(c, "#")
		r, g, b := hexRGB(c)
		return ok && r >= 0 && g >= 0 && b >= 0
	}
	for _, th := range themes {
		for name, c := range map[string]string{
			"Bg": string(th.Bg), "Border": string(th.Border), "Faint": string(th.Faint),
			"Text": string(th.Text), "Muted": string(th.Muted), "Live": string(th.Live),
			"Accent": string(th.Accent), "Accent2": string(th.Accent2), "Win": string(th.Win),
			"Warn": string(th.Warn), "Goal": string(th.Goal),
		} {
			if !valid(c) {
				t.Errorf("%s.%s = %q is not #RRGGBB", th.ID, name, c)
			}
		}
	}
}

// applyTheme must repoint both the color globals and the derived styles.
func TestApplyThemeUpdatesGlobalsAndStyles(t *testing.T) {
	applyTheme(themes[themeIndex("uchu")])
	if colText != themes[themeIndex("uchu")].Text {
		t.Errorf("colText not updated: %v", colText)
	}
	if got := styleScore.GetForeground(); got != colText {
		t.Errorf("styleScore foreground %v != colText %v", got, colText)
	}
	if colWarnHex != strings.TrimPrefix(string(colWarn), "#") {
		t.Errorf("colWarnHex %q out of sync with colWarn %v", colWarnHex, colWarn)
	}
	// Restore default so other tests see the original palette.
	applyTheme(themes[0])
}

// themeIndex is forgiving: unknown / empty IDs fall back to the default (0).
func TestThemeIndexFallback(t *testing.T) {
	if themeIndex("") != 0 || themeIndex("nope") != 0 {
		t.Error("unknown theme id should map to index 0")
	}
	if themeIndex("humdrum-dark") != themeIndex("humdrum-dark") {
		t.Error("themeIndex not stable")
	}
}

func TestPaintBackgroundFillsAndReasserts(t *testing.T) {
	applyTheme(themes[0])
	const reset = "\x1b[0m"
	// A line with an inner reset (as lipgloss would emit after a styled span).
	in := "hi" + reset + "yo"
	out := paintBackground(in, 10)

	// Base (fg+bg truecolor) must lead the line.
	if !strings.HasPrefix(out, "\x1b[38;2;") {
		t.Fatalf("no leading base SGR: %q", out)
	}
	// The inner reset must be followed by a re-asserted background, so text
	// after it isn't left on the terminal's own background.
	if !strings.Contains(out, reset+"\x1b[38;2;") {
		t.Errorf("reset not followed by base re-assert: %q", out)
	}
	// Line padded to the full width (printable width == 10) and ends reset.
	if w := lipgloss.Width(out); w != 10 {
		t.Errorf("painted width = %d, want 10", w)
	}
	if !strings.HasSuffix(out, reset) {
		t.Errorf("line should end with reset: %q", out)
	}
}

func TestThemesForSplitsByAppearance(t *testing.T) {
	dark := themesFor(true)
	light := themesFor(false)
	if len(dark) != 3 || len(light) != 3 {
		t.Fatalf("expected 3 dark + 3 light, got %d/%d", len(dark), len(light))
	}
	for _, i := range dark {
		if !themes[i].Dark {
			t.Errorf("themesFor(true) returned light theme %s", themes[i].ID)
		}
	}
	for _, i := range light {
		if themes[i].Dark {
			t.Errorf("themesFor(false) returned dark theme %s", themes[i].ID)
		}
	}
}

func TestResolveThemeHonorsAppearance(t *testing.T) {
	// Persisted dark theme, but terminal is light → fall back to a light theme.
	got := resolveTheme("flexoki-dark", false)
	if themes[got].Dark {
		t.Errorf("light terminal resolved to dark theme %s", themes[got].ID)
	}
	// Persisted theme matches appearance → keep it.
	if got := resolveTheme("uchu-dark", true); themes[got].ID != "uchu-dark" {
		t.Errorf("matching persisted theme not kept: %s", themes[got].ID)
	}
	// Empty → first of appearance.
	if got := resolveTheme("", true); !themes[got].Dark {
		t.Errorf("empty config on dark terminal gave light theme %s", themes[got].ID)
	}
}