package web

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// everything a helix theme reader has to survive: quoted scope keys, a
// palette, one of the terminal color names, modifiers, and an inline table
// broken over lines the way a formatter leaves it
const helixSrc = `
# a comment
"ui.background" = { bg = "base" }
"ui.text" = { fg = "text" }
"ui.linenr" = { fg = "muted" }
"ui.statusline" = { fg = "text", bg = "surface" }
"ui.cursorline.primary" = { bg = "highlight" }
"ui.menu.selected" = { fg = "base", bg = "rose" }
"ui.window" = { fg = "muted" }
comment = { fg = "muted", modifiers = ["italic"] }
keyword = { fg = "pine", modifiers = [
  "bold",
] }
string = "gold"
function = { fg = "rose" }
"constant.numeric" = { fg = "iris" }
"variable.other.member" = { fg = "foam" }
"punctuation" = { fg = "muted" }
warning = { fg = "gold" }
type = "white"

[palette]
base = "#191724"
text = "#e0def4"
muted = "#6e6a86"
surface = "#1f1d2e"
highlight = "#21202e"
pine = "#31748f"
gold = "#f6c177"
rose = "#ebbcba"
iris = "#c4a7e7"
foam = "#9ccfd8"
`

func writeTheme(t *testing.T, dir, name, body string) string {
	t.Helper()
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(dir, name)
	if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestHelixTheme(t *testing.T) {
	dir := t.TempDir()
	path := writeTheme(t, dir, "rose_pine.toml", helixSrc)
	th := loadHelixTheme(path, []string{dir})
	if th == nil {
		t.Fatal("theme did not load")
	}
	for _, tc := range []struct{ what, got, want string }{
		{"id", th.ID, "helix/rose-pine"},
		{"source", th.Source, "helix"},
		{"name", th.Name, "rose_pine"},
		{"appearance", th.Appearance, "dark"},
		{"bg", th.Bg, "#191724"},
		{"fg", th.Fg, "#e0def4"},
		{"panel", th.Panel, "#1f1d2e"},
		{"line numbers", th.LineNo, "#6e6a86"},
		{"border", th.Border, "#6e6a86"},
		{"accent", th.Accent, "#ebbcba"}, // function
		{"note", th.Note, "#f6c177"},     // warning
		{"hover", th.Hover, "#21202e"},   // cursorline, not the loud menu row
		{"muted", th.Muted, "#6e6a86"},   // comment
	} {
		if tc.got != tc.want {
			t.Errorf("%s = %q, want %q", tc.what, tc.got, tc.want)
		}
	}
	// syntax keys the site paints with, spelled the way helix spells them
	for _, tc := range []struct{ key, want string }{
		{"comment", "#6e6a86"},
		{"keyword", "#31748f"},
		{"string", "#f6c177"},
		{"type", "#e5e5e5"},                // a terminal color name, not a palette one
		{"number", "#c4a7e7"},              // zed's name for constant.numeric
		{"property", "#9ccfd8"},            // zed's name for variable.other.member
		{"punctuation.bracket", "#6e6a86"}, // falls back along its dots
	} {
		if got := th.syn(tc.key); got != tc.want {
			t.Errorf("syntax %s = %q, want %q", tc.key, got, tc.want)
		}
	}
	if s := th.Syntax["comment"]; s.FontStyle == nil || *s.FontStyle != "italic" {
		t.Errorf("comment is not italic: %+v", s)
	}
	if s := th.Syntax["keyword"]; s.FontWeight == nil || *s.FontWeight != 700 {
		t.Errorf("keyword is not bold: %+v", s)
	}
	// agent colors: from the code's own colors, and none of them invisible
	if len(th.Players) < 3 {
		t.Fatalf("agent colors = %v, want at least 3", th.Players)
	}
	for _, p := range th.Players {
		if colorDist(p, hex6(th.Bg)) <= 60 || colorDist(p, hex6(th.Fg)) <= 60 {
			t.Errorf("agent color %s vanishes against the theme", p)
		}
	}
}

// A child theme restating only the palette is how helix ships most of its
// families: the parent's scopes have to resolve against the child's colors.
func TestHelixInherits(t *testing.T) {
	dir := t.TempDir()
	writeTheme(t, dir, "parent.toml", helixSrc)
	path := writeTheme(t, dir, "child.toml", `
inherits = "parent"
comment = { fg = "muted" }

[palette]
base = "#eff1f5"
text = "#4c4f69"
muted = "#7c7f93"
surface = "#e6e9ef"
highlight = "#dce0e8"
pine = "#1e66f5"
gold = "#df8e1d"
rose = "#ea76cb"
iris = "#8839ef"
foam = "#04a5e5"
`)
	th := loadHelixTheme(path, []string{dir})
	if th == nil {
		t.Fatal("child theme did not load")
	}
	if th.Bg != "#eff1f5" || th.Fg != "#4c4f69" {
		t.Errorf("inherited scopes kept the parent's palette: bg=%s fg=%s", th.Bg, th.Fg)
	}
	if th.Appearance != "light" {
		t.Errorf("appearance = %q, want light for a pale background", th.Appearance)
	}
	if got := th.syn("keyword"); got != "#1e66f5" {
		t.Errorf("inherited keyword = %q, want the child's pine", got)
	}
	// the child's own entry wins over the parent's, modifiers and all
	if s := th.Syntax["comment"]; s.FontStyle != nil {
		t.Errorf("child comment kept the parent's italics: %+v", s)
	}
}

// A theme that names almost nothing still has to dress a whole page.
func TestFillClosesTheGaps(t *testing.T) {
	th := &Theme{Bg: "#101010", Fg: "#f0f0f0", Syntax: map[string]SyntaxStyle{
		"function": {Color: "#88c0d0"},
	}}
	th.fill()
	for _, tc := range []struct{ what, got string }{
		{"panel", th.Panel}, {"border", th.Border}, {"line numbers", th.LineNo},
		{"muted", th.Muted}, {"accent", th.Accent}, {"note", th.Note}, {"hover", th.Hover},
	} {
		if okColor(tc.got) == "" {
			t.Errorf("%s = %q, want a color", tc.what, tc.got)
		}
	}
	if th.Accent != "#88c0d0" {
		t.Errorf("accent = %q, want the theme's own function color", th.Accent)
	}
	if th.Panel == th.Bg || th.Hover == th.Bg {
		t.Errorf("panel %q and hover %q must lift off the background %q", th.Panel, th.Hover, th.Bg)
	}
	// a panel the text would be lost in is not kept
	lost := &Theme{Bg: "#f7f3ee", Fg: "#605a52", Panel: "#605a52"}
	lost.fill()
	if lost.Panel == "#605a52" {
		t.Error("kept a panel the foreground disappears into")
	}
}

func TestZedFamily(t *testing.T) {
	fam, err := parseZedFamily([]byte(`{"name":"Fake","themes":[
		{"name":"Fake Dark","appearance":"dark","style":{
			"editor.background":"#101010","editor.foreground":"#e0e0e0",
			"text.accent":"0f4b6e","warning":"#e0af68",
			"players":[{"cursor":"#7aa2f7"},{"cursor":"#9ece6a"}],
			"syntax":{"keyword":{"color":"#bb9af7","font_style":"italic"},
			          "string":{"color":"9ece6a"}}}},
		{"name":"Fake Light","appearance":"light","style":{
			"editor.background":"#fafafa","editor.foreground":"#383a42"}}]}`))
	if err != nil {
		t.Fatal(err)
	}
	if len(fam) != 2 {
		t.Fatalf("themes = %d, want 2", len(fam))
	}
	dark, light := fam[0], fam[1]
	if dark.ID != "zed/fake-dark" || light.ID != "zed/fake-light" {
		t.Errorf("ids = %q, %q", dark.ID, light.ID)
	}
	// a theme in the wild does drop the odd "#": what is not a color is
	// treated as unsaid, and filled in rather than emitted as nonsense
	if dark.Accent == "0f4b6e" {
		t.Error("kept a color with no #")
	}
	if _, ok := dark.Syntax["string"]; ok {
		t.Error("kept a syntax color with no #")
	}
	if dark.syn("keyword") != "#bb9af7" {
		t.Errorf("keyword = %q", dark.syn("keyword"))
	}
	if len(dark.Players) < 2 || dark.Players[0] != "#7aa2f7" {
		t.Errorf("agent colors = %v, want the player palette first", dark.Players)
	}
	// nothing to work from but bg and fg, and still a whole theme
	if okColor(light.Muted) == "" || okColor(light.Hover) == "" {
		t.Errorf("light theme left gaps: %+v", light)
	}
}

// The picker's two files: a block per theme, and a menu that names them.
func TestThemeFiles(t *testing.T) {
	dark, light := loadTheme("", "", "dark"), loadTheme("", "", "light")
	helix := loadHelixTheme(writeTheme(t, t.TempDir(), "rose_pine.toml", helixSrc), nil)
	ts := themesFrom([]*Theme{dark, light, helix}, dark, light)

	css := string(ts.CSS)
	for _, th := range ts.List {
		if !strings.Contains(css, `:root[data-theme="`+th.ID+`"]`) {
			t.Errorf("no css block for %s", th.ID)
		}
		if !strings.Contains(string(ts.JS), th.ID) {
			t.Errorf("%s is not in the menu", th.ID)
		}
	}
	for _, want := range []string{"--bg:", "--fg:", "--ag0:", "color-scheme: dark", "color-scheme: light"} {
		if !strings.Contains(css, want) {
			t.Errorf("themes.css never says %q", want)
		}
	}
	// every declaration has to be worth something to the browser
	for _, line := range strings.Split(css, "\n") {
		if l := strings.TrimSpace(line); strings.HasPrefix(l, "--") && strings.HasSuffix(l, ": ;") {
			t.Errorf("empty declaration: %s", l)
		}
	}
	if n := strings.Count(string(ts.JS), `"id":`); n != len(ts.List) {
		t.Errorf("menu has %d themes, want %d", n, len(ts.List))
	}
}

// The two editors' theme directories, as they are on a machine that has them.
func TestDiscoverFindsBothEditors(t *testing.T) {
	home := t.TempDir()
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, "config"))
	t.Setenv("XDG_DATA_HOME", filepath.Join(home, "data"))
	writeTheme(t, filepath.Join(home, "config", "zed", "themes"), "mine.json",
		`{"name":"Mine","themes":[{"name":"Mine Dark","appearance":"dark","style":{
			"editor.background":"#101010","editor.foreground":"#e0e0e0"}}]}`)
	writeTheme(t, filepath.Join(home, "data", "zed", "extensions", "installed", "ext", "themes"),
		"ext.json", `{"name":"Ext","themes":[{"name":"Ext Light","appearance":"light","style":{
			"editor.background":"#fafafa","editor.foreground":"#383a42"}}]}`)
	writeTheme(t, filepath.Join(home, "config", "helix", "themes"), "mine_helix.toml", helixSrc)

	found := map[string]*Theme{}
	for _, th := range discoverThemes() {
		found[th.ID] = th
	}
	for _, want := range []string{"zed/mine-dark", "zed/ext-light", "helix/mine-helix"} {
		if found[want] == nil {
			t.Errorf("did not find %s", want)
		}
	}
}

// Coverage colors are mixed in the browser so every theme can supply them.
func TestMaskMix(t *testing.T) {
	s := &Site{Agents: []*Agent{{Bit: 1}, {Bit: 2}, {Bit: 4}}}
	for _, tc := range []struct {
		mask uint8
		want string
	}{
		{1, "var(--ag0)"},
		{5, "color-mix(in srgb, var(--ag0) 50.000%, var(--ag2))"},
		{7, "color-mix(in srgb, var(--ag0) 33.333%, color-mix(in srgb, var(--ag1) 50.000%, var(--ag2)))"},
	} {
		if got := s.maskMix(tc.mask); got != tc.want {
			t.Errorf("mask %d = %q, want %q", tc.mask, got, tc.want)
		}
	}
}