package rgb

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

	"netdome.biz/paul/qmk-rgb/internal/via"
)

// A definition may attach a number to an option that is not its position in the
// list, so the ID has to come from the number and not from the index. This
// fixture names three effects at IDs 1, 2 and 5 and leaves 0, 3 and 4 unnamed.
func TestLoadDefinitionReadsEffectIDsFromTheOptions(t *testing.T) {
	def := loadDefinitionFixture(t, "tuple_options.json")

	effects := def.Catalog.Effects(via.ChannelRgbMatrix)
	if len(effects) != 3 {
		t.Fatalf("rgb_matrix effects = %d, want 3", len(effects))
	}
	want := []Effect{{ID: 1, Name: "Solid Color"}, {ID: 2, Name: "Breathing"}, {ID: 5, Name: "Rainbow"}}
	for i, w := range want {
		if effects[i] != w {
			t.Errorf("effects[%d] = %+v, want %+v", i, effects[i], w)
		}
	}

	// A gap must report unknown rather than the next name along.
	for _, id := range []uint8{0, 3, 4, 6} {
		if got := def.Catalog.EffectName(via.ChannelRgbMatrix, id); got != unknownEffectName {
			t.Errorf("EffectName(rgb_matrix, %d) = %q, want %q", id, got, unknownEffectName)
		}
	}
}

// The same effect is reachable by name, which is what `effect <name>` needs.
func TestDefinitionEffectsResolveByName(t *testing.T) {
	def := loadDefinitionFixture(t, "tuple_options.json")

	id, ok := def.Catalog.EffectID(via.ChannelRgbMatrix, "Rainbow")
	if !ok || id != 5 {
		t.Errorf("EffectID(rgb_matrix, \"Rainbow\") = %d, %t, want 5, true", id, ok)
	}
	if _, ok := def.Catalog.EffectID(via.ChannelRgbMatrix, "Solid"); ok {
		t.Error("EffectID(rgb_matrix, \"Solid\") = found, want not found")
	}
}

// Plain string options carry no number, and the position is the ID.
func TestLoadDefinitionNumbersStringOptionsByPosition(t *testing.T) {
	def := loadDefinitionFixture(t, "string_options.json")

	effects := def.Catalog.Effects(via.ChannelRgblight)
	want := []Effect{{ID: 0, Name: "All Off"}, {ID: 1, Name: "Solid Color"}, {ID: 2, Name: "Breathing 1"}, {ID: 3, Name: "Breathing 2"}}
	if len(effects) != len(want) {
		t.Fatalf("rgblight effects = %d, want %d", len(effects), len(want))
	}
	for i, w := range want {
		if effects[i] != w {
			t.Errorf("effects[%d] = %+v, want %+v", i, effects[i], w)
		}
	}
}

// VIA serves built definitions that carry vendorProductId as a number and no
// vendorId/productId pair, so both spellings have to be read.
func TestDefinitionIdentifiesTheBoardFromEitherSpelling(t *testing.T) {
	tests := []struct {
		file       string
		wantVendor uint16
		wantProd   uint16
	}{
		{"tuple_options.json", 0x1234, 0x5678},
		{"string_options.json", 0x1234, 0x5678},
	}
	for _, tt := range tests {
		def := loadDefinitionFixture(t, tt.file)
		if def.VendorID != tt.wantVendor || def.ProductID != tt.wantProd {
			t.Errorf("%s: vendor/product = 0x%04x/0x%04x, want 0x%04x/0x%04x",
				tt.file, def.VendorID, def.ProductID, tt.wantVendor, tt.wantProd)
		}
	}
	if got := loadDefinitionFixture(t, "string_options.json").Name; got != "Served Board" {
		t.Errorf("name = %q, want %q", got, "Served Board")
	}
}

// Brightness, color and speed controls are not effect lists and must not become
// one.
func TestLoadDefinitionIgnoresOtherControls(t *testing.T) {
	def := loadDefinitionFixture(t, "tuple_options.json")

	for _, ch := range []via.Channel{via.ChannelBacklight, via.ChannelRgbMatrix} {
		for _, e := range def.Catalog.Effects(ch) {
			if e.Name == "" {
				t.Errorf("channel %v has an effect without a name", ch)
			}
		}
	}
	if got := def.Catalog.Effects(via.ChannelRgbMatrix); len(got) != 3 {
		t.Errorf("rgb_matrix effects = %d, want 3 (brightness and color excluded)", len(got))
	}
}

// A definition is matched to a board by its VID/PID, so a directory can hold
// many of them and the wrong one must not be used.
func TestFindDefinitionMatchesTheBoard(t *testing.T) {
	dir := t.TempDir()
	copyFixture(t, dir, "tuple_options.json")

	defs, err := LoadDefinitionsDir(dir)
	if err != nil {
		t.Fatalf("LoadDefinitionsDir() error = %v", err)
	}
	if len(defs) != 1 {
		t.Fatalf("definitions = %d, want 1", len(defs))
	}

	if got := FindDefinition(defs, 0x1234, 0x5678); got == nil {
		t.Error("FindDefinition(matching) = nil, want the definition")
	}
	if got := FindDefinition(defs, 0x36B0, 0x309F); got != nil {
		t.Error("FindDefinition(other board) = a definition, want nil")
	}
}

// A file that is not a definition, or not one for any board, is reported rather
// than skipped in silence.
func TestLoadDefinitionsDirRejectsUnusableFiles(t *testing.T) {
	dir := t.TempDir()
	if err := os.WriteFile(filepath.Join(dir, "broken.json"), []byte("{not json"), 0o600); err != nil {
		t.Fatal(err)
	}

	if _, err := LoadDefinitionsDir(dir); err == nil {
		t.Error("LoadDefinitionsDir(broken json) = nil error, want an error")
	}
}

func TestLoadDefinitionRejectsAMissingFile(t *testing.T) {
	if _, err := LoadDefinition(filepath.Join(t.TempDir(), "nope.json")); err == nil {
		t.Error("LoadDefinition(missing) = nil error, want an error")
	}
}

func loadDefinitionFixture(t *testing.T, name string) *Definition {
	t.Helper()
	def, err := LoadDefinition(filepath.Join("testdata", name))
	if err != nil {
		t.Fatalf("LoadDefinition(%s) error = %v", name, err)
	}
	return def
}

func copyFixture(t *testing.T, dir, name string) {
	t.Helper()
	data, err := os.ReadFile(filepath.Join("testdata", name))
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, name), data, 0o600); err != nil {
		t.Fatal(err)
	}
}

// A definition carries the manufacturer's own spelling, and the tool's aliases
// are a spelling convenience rather than board knowledge, so they have to work
// whichever spelling a definition happens to use. The vendor of this board
// writes "breathe" where the compiled-in catalog writes "breathing".
func TestDefinitionCatalogResolvesTheToolsAliasesBothWays(t *testing.T) {
	names := []Effect{{ID: 0, Name: "none"}, {ID: 3, Name: "spectrum"}, {ID: 4, Name: "breathe"}, {ID: 5, Name: "light"}}
	catalog := NewCatalog("vendor", map[via.Channel][]Effect{via.ChannelRgblight: names})

	tests := []struct {
		name   string
		effect string
		want   uint8
	}{
		{"the vendor's own spelling", "breathe", 4},
		{"the tool's canonical name", "breathing", 4},
		{"an alias that the channel has", "off", 0},
		{"an alias that resolves per channel", "rainbow", 3},
		{"a name no alias or entry reaches", "nonsense", 0},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			id, ok := catalog.EffectID(via.ChannelRgblight, tt.effect)
			if tt.effect == "nonsense" {
				if ok {
					t.Errorf("EffectID(%q) = %d, true, want not found", tt.effect, id)
				}
				return
			}
			if !ok || id != tt.want {
				t.Errorf("EffectID(%q) = %d, %t, want %d, true", tt.effect, id, ok, tt.want)
			}
		})
	}
}

// The compiled-in catalog keeps working exactly as before.
func TestBuiltInCatalogStillResolvesItsAliases(t *testing.T) {
	catalog := impact80(t)

	tests := []struct {
		channel via.Channel
		effect  string
		want    uint8
	}{
		{via.ChannelRgblight, "breathing", 4},
		{via.ChannelRgblight, "breathe", 4},
		{via.ChannelRgblight, "off", 0},
		{via.ChannelRgbMatrix, "breathing", 5},
		{via.ChannelRgbMatrix, "rainbow", 17},
		{via.ChannelAudio, "rainbow", 3},
	}
	for _, tt := range tests {
		id, ok := catalog.EffectID(tt.channel, tt.effect)
		if !ok || id != tt.want {
			t.Errorf("EffectID(%v, %q) = %d, %t, want %d, true", tt.channel, tt.effect, id, ok, tt.want)
		}
	}
}

// A definition writes display spellings ("fixed wave") where the tool writes
// identifiers ("fixed_wave"). The difference is whitespace, not a different
// effect, so both must resolve — the tool's documented name may not stop working
// because a definition file happens to be present.
func TestDefinitionCatalogResolvesSpacesAsUnderscores(t *testing.T) {
	names := []Effect{{ID: 0, Name: "none"}, {ID: 1, Name: "wave"}, {ID: 2, Name: "fixed wave"}}
	catalog := NewCatalog("vendor", map[via.Channel][]Effect{via.ChannelRgblight: names})

	tests := []struct {
		effect string
		want   uint8
	}{
		{"fixed wave", 2},
		{"fixed_wave", 2},
		{"wave", 1},
	}
	for _, tt := range tests {
		id, ok := catalog.EffectID(via.ChannelRgblight, tt.effect)
		if !ok || id != tt.want {
			t.Errorf("EffectID(%q) = %d, %t, want %d, true", tt.effect, id, ok, tt.want)
		}
	}
}

// The compiled-in catalog has no spaced names, so the rule changes nothing there.
func TestBuiltInCatalogIsUnchangedByTheSpacingRule(t *testing.T) {
	catalog := impact80(t)

	if id, ok := catalog.EffectID(via.ChannelRgblight, "fixed_wave"); !ok || id != 2 {
		t.Errorf("EffectID(rgblight, \"fixed_wave\") = %d, %t, want 2, true", id, ok)
	}
	if _, ok := catalog.EffectID(via.ChannelRgbMatrix, "fixed_wave"); ok {
		t.Error("EffectID(rgb_matrix, \"fixed_wave\") = found, want not found: only the rgblight channel has it")
	}
}

// The sub-menu a definition puts a lighting channel under is that channel's name
// in VIA's own interface, and it is board data the file already carries. Using
// it means the tool and VIA call the same channel the same thing, instead of
// the tool inventing a third name.
func TestDefinitionNamesItsChannelsBySubMenu(t *testing.T) {
	def := loadDefinitionFixture(t, "tuple_options.json")

	want := map[uint16]string{2: "logo", 3: "Backlight", 4: "side"}
	for channel, label := range want {
		if got := def.Labels[channel]; got != label {
			t.Errorf("Labels[%d] = %q, want %q", channel, got, label)
		}
	}
	if len(def.Labels) != len(want) {
		t.Errorf("Labels = %v, want only the lighting channels", def.Labels)
	}
}

// The label is whatever the definition calls the channel, not a name this tool
// knows: a different definition calls the same channel Underglow, and that name
// is the one VIA shows.
func TestDefinitionTakesWhateverTheChannelIsCalled(t *testing.T) {
	def := loadDefinitionFixture(t, "string_options.json")

	if got := def.Labels[2]; got != "Underglow" {
		t.Errorf("Labels[2] = %q, want %q", got, "Underglow")
	}
	if len(def.Labels) != 1 {
		t.Errorf("Labels = %v, want only the channel the definition names", def.Labels)
	}
}

// The definition files in the repository are read at runtime, so a truncated or
// edited one would fail every command that names an effect rather than fail a
// test. This parses the vendored Impact 80 file and checks what it has to
// contain.
func TestVendoredImpact80DefinitionIsUsable(t *testing.T) {
	def, err := LoadDefinition(filepath.Join("..", "..", "definitions", "impact80.json"))
	if err != nil {
		t.Fatalf("LoadDefinition(definitions/impact80.json) error = %v", err)
	}

	if def.VendorID != 0x36B0 || def.ProductID != 0x309F {
		t.Errorf("identifiers = 0x%04X/0x%04X, want 0x36B0/0x309F", def.VendorID, def.ProductID)
	}

	want := map[via.Channel]int{
		via.ChannelRgblight:  7,
		via.ChannelRgbMatrix: 46,
		via.ChannelAudio:     7,
	}
	for ch, count := range want {
		if got := len(def.Catalog.Effects(ch)); got != count {
			t.Errorf("channel %v has %d effects, want %d", ch, got, count)
		}
	}

	// The names are the vendor's, and the tool's spelling has to resolve too.
	if id, ok := def.Catalog.EffectID(via.ChannelRgblight, "fixed wave"); !ok || id != 2 {
		t.Errorf("EffectID(rgblight, \"fixed wave\") = %d, %t, want 2, true", id, ok)
	}
	if id, ok := def.Catalog.EffectID(via.ChannelRgblight, "fixed_wave"); !ok || id != 2 {
		t.Errorf("EffectID(rgblight, \"fixed_wave\") = %d, %t, want 2, true", id, ok)
	}
	if got := def.Labels[3]; got != "Backlight" {
		t.Errorf("Labels[3] = %q, want %q", got, "Backlight")
	}
}