package main

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

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

// generateStub is a keyboard that answers an effect range, so a generated names
// file can be checked without hardware. The Vial fields are what a keyboard
// running Vial firmware would answer; a zero version reads as one that is not
// Vial.
type generateStub struct {
	tops    map[intvia.Channel]int
	vial    bool
	vialIDs []uint16
}

func (g generateStub) EffectTop(ch intvia.Channel) (int, error) { return g.tops[ch], nil }

func (g generateStub) VialVersion() (uint32, bool, error) {
	if !g.vial {
		return 0, false, nil
	}
	return 6, true, nil
}

func (g generateStub) VialEffectIDs() ([]uint16, error) { return g.vialIDs, nil }

func (g generateStub) GetValue(intvia.Channel, uint8) ([]byte, error) { return []byte{0}, nil }

func (g generateStub) SetValue(intvia.Channel, uint8, uint8) error { return nil }

func (g generateStub) SetColor(intvia.Channel, uint8, uint8) error { return nil }

func (g generateStub) DetectChannels() ([]intvia.Channel, error) { return nil, nil }

func (g generateStub) Close() error { return nil }

// stubGenerateTarget makes the connected keyboard a fixed one. The identifiers are
// a parameter because a board the binary carries a definition for is a different
// case from one it does not, and a stub for the wrong board would test nothing.
func stubGenerateTarget(t *testing.T, vendorID, productID uint16, channels []intvia.Channel, stub generateStub) {
	t.Helper()
	original := openTarget
	t.Cleanup(func() { openTarget = original })
	openTarget = func(string) (rgbProtocol, targetDeviceData, []intvia.Channel, error) {
		return stub, stubTargetData(vendorID, productID), channels, nil
	}
}

func forceGenerateRestore(t *testing.T) func() {
	t.Helper()
	original := generateForce
	return func() { generateForce = original }
}

// forceNamesDir points the names directory at a test directory. Without it a test
// that writes a names file writes into the user's real data directory, which is
// what happened when this override did not exist yet.
func forceNamesDir(t *testing.T, dir string) func() {
	t.Helper()
	original := namesDirOverride
	namesDirOverride = dir
	return func() { namesDirOverride = original }
}

// generateSetup points every writable directory at one temporary directory, so a
// test cannot reach the user's.
// generateSetup points the writable directories at temporary ones and returns the
// names directory. They are two directories on purpose: a names file in the
// definitions directory parses as a definition — it carries the board's
// identifiers and no menus — and takes the board's place, which is exactly what
// TestNamesFileInTheDefinitionsDirectoryIsNotADefinition is about.
func generateSetup(t *testing.T) string {
	t.Helper()
	names := t.TempDir()
	t.Cleanup(definitionFlagRestore(t))
	t.Cleanup(forceDefinitionsDir(t, t.TempDir()))
	t.Cleanup(forceNamesDir(t, names))
	t.Cleanup(forceGenerateRestore(t))
	return names
}

func runGenerate(t *testing.T) (string, string) {
	t.Helper()
	cmd := NewKeyboardDefinitionsGenerateCmd()
	var out, errOut strings.Builder
	cmd.SetOut(&out)
	cmd.SetErr(&errOut)
	if err := cmd.Execute(); err != nil {
		t.Fatalf("definitions generate error = %v (stderr %q)", err, errOut.String())
	}
	return out.String(), errOut.String()
}

func onlyNamesFile(t *testing.T, dir string) string {
	t.Helper()
	matches, err := filepath.Glob(filepath.Join(dir, "*.json"))
	if err != nil {
		t.Fatal(err)
	}
	if len(matches) != 1 {
		t.Fatalf("names dir = %v, want one file", matches)
	}
	return matches[0]
}

func mustRead(t *testing.T, path string) string {
	t.Helper()
	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	return string(data)
}

// A generated file names no effect, so a board reports the same "no names" it
// reported before one existed. A name the tool wrote would be indistinguishable
// from the manufacturer's, and nothing in a file can be read back off a keyboard
// to check it.
func TestGeneratedNamesFileNamesNoEffectUntilTheUserFillsItIn(t *testing.T) {
	dir := generateSetup(t)
	stubGenerateTarget(t, 0x1234, 0x5678, []intvia.Channel{intvia.ChannelRgbMatrix},
		generateStub{tops: map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45}})

	runGenerate(t)

	path := onlyNamesFile(t, dir)
	names, err := intrgbLoadNamesFile(path)
	if err != nil {
		t.Fatalf("LoadNamesFile(%s) error = %v; the generated file has to load", path, err)
	}
	if got := len(names.Effects(intvia.ChannelRgbMatrix)); got != 0 {
		t.Errorf("effects on rgb_matrix = %d, want 0 until the names are written in", got)
	}
	// The slots are still there, which is the other half: the file says which IDs
	// the board has and leaves the naming to the user.
	body := mustRead(t, path)
	for _, want := range []string{`"0": ""`, `"7": ""`, `"45": ""`} {
		if !strings.Contains(body, want) {
			t.Errorf("generated file has no empty slot %s", want)
		}
	}
	// And it is one line per effect, not a nested menu description to dig through.
	if lines := strings.Count(body, "\n"); lines > 60 {
		t.Errorf("generated file is %d lines, want roughly one per effect", lines)
	}
}

// A names file is the one the user would have run the command to write, so a
// second run must not replace it.
func TestGenerateDoesNotReplaceAStoredNamesFile(t *testing.T) {
	dir := generateSetup(t)
	stubGenerateTarget(t, 0x1234, 0x5678, []intvia.Channel{intvia.ChannelRgbMatrix},
		generateStub{tops: map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45}})

	written := `{"vendorId":"0x1234","productId":"0x5678","channels":{"rgb_matrix":{"7":"mine"}}}`
	if err := os.WriteFile(filepath.Join(dir, "board.json"), []byte(written), 0o644); err != nil {
		t.Fatal(err)
	}

	cmd := NewKeyboardDefinitionsGenerateCmd()
	var out, errOut strings.Builder
	cmd.SetOut(&out)
	cmd.SetErr(&errOut)
	err := cmd.Execute()
	if err == nil {
		t.Fatal("definitions generate = nil error, want a refusal to replace a stored names file")
	}
	if !strings.Contains(err.Error(), "--force") {
		t.Errorf("error = %q, want it to offer --force", err)
	}
	if got := mustRead(t, filepath.Join(dir, "board.json")); got != written {
		t.Errorf("stored file = %q, want it untouched (%q)", got, written)
	}
}

// The note beside the file is what carries the names, because a JSON file cannot:
// the tool would have to read comments and VIA's parser would reject them. It has
// to say who wrote what, or a name is a guess wearing a count.
func TestGeneratedNoteCarriesTheSpellingsAndWhoWroteThem(t *testing.T) {
	dir := generateSetup(t)
	stubGenerateTarget(t, 0x1234, 0x5678, []intvia.Channel{intvia.ChannelRgbMatrix},
		generateStub{tops: map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45}})

	runGenerate(t)

	note := mustRead(t, strings.TrimSuffix(onlyNamesFile(t, dir), ".json")+spottedNoteSuffix)
	for _, want := range []string{
		"rgb_matrix (channel 3)",
		"rainbow_moving_chevron",
		"boards:",
		"keychron",
		string(slotsMeasured),
	} {
		if !strings.Contains(note, want) {
			t.Errorf("note does not carry %q", want)
		}
	}
}

// A Vial keyboard lists its own rgb_matrix effect IDs, and the tool must use those
// rather than writing above the top: the list is the firmware answering without
// being touched.
func TestGenerateUsesVialsOwnListWhenTheFirmwareIsVial(t *testing.T) {
	dir := generateSetup(t)
	stubGenerateTarget(t, 0x1234, 0x5678,
		[]intvia.Channel{intvia.ChannelRgbMatrix, intvia.ChannelRgblight},
		generateStub{
			tops:    map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45, intvia.ChannelRgblight: 6},
			vial:    true,
			vialIDs: []uint16{0, 1, 2, 40, 45},
		})

	out, _ := runGenerate(t)

	if !strings.Contains(out, "Vial firmware") {
		t.Errorf("stdout = %q, want it to say the keyboard is Vial", out)
	}
	if !strings.Contains(out, experimentalVial) {
		t.Errorf("stdout = %q, want the Vial path marked %s", out, experimentalVial)
	}
	// rgb_matrix keeps the firmware's own numbering, gaps and all; rgblight has no
	// Vial list and falls back to the clamp.
	if !strings.Contains(out, "0, 1, 2, 40, 45") {
		t.Errorf("stdout = %q, want the rgb_matrix slots in the firmware's numbering", out)
	}
	if !strings.Contains(out, string(slotsReported)) || !strings.Contains(out, string(slotsMeasured)) {
		t.Errorf("stdout = %q, want both sources named per channel", out)
	}

	// The note must not put QMK's spellings next to numbers that are not QMK's.
	note := mustRead(t, strings.TrimSuffix(onlyNamesFile(t, dir), ".json")+spottedNoteSuffix)
	if strings.Contains(note, "rainbow_moving_chevron") {
		t.Errorf("note = %q, want no QMK spellings beside a Vial numbering", note)
	}
	if !strings.Contains(note, "VIALRGB_EFFECT_*") {
		t.Errorf("note = %q, want it to say the numbering is the firmware's own", note)
	}
}

// A Vial keyboard built without VIALRGB_ENABLE answers nothing, and a board that
// cannot list its effects can still be asked by writing above the top.
func TestGenerateFallsBackToTheClampWhenVialListsNothing(t *testing.T) {
	dir := generateSetup(t)
	stubGenerateTarget(t, 0x1234, 0x5678, []intvia.Channel{intvia.ChannelRgbMatrix},
		generateStub{tops: map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45}, vial: true})

	out, _ := runGenerate(t)

	if !strings.Contains(out, string(slotsMeasured)) {
		t.Errorf("stdout = %q, want the clamp used when Vial lists nothing", out)
	}
	note := mustRead(t, strings.TrimSuffix(onlyNamesFile(t, dir), ".json")+spottedNoteSuffix)
	if !strings.Contains(note, "rainbow_moving_chevron") {
		t.Errorf("note = %q, want the QMK spellings again, which is what the clamp gives", note)
	}
}

// The point of storing names apart from the definition: a name the user writes
// replaces the vendor's for that one effect, and the rest of the file still stands.
// The board is the Impact 80, whose definition the binary carries, so "the rest"
// means real names the vendor wrote.
func TestANameTheUserWroteOverridesOneEffectAndLeavesTheRest(t *testing.T) {
	generateSetup(t)
	names := t.TempDir()
	t.Cleanup(forceNamesDir(t, names))

	body := `{"name":"Impact 80","vendorId":"0x36B0","productId":"0x309F",
		"channels":{"rgb_matrix":{"7":"my_chevron"}}}`
	if err := os.WriteFile(filepath.Join(names, "impact80.json"), []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}

	catalog, _, err := resolveCatalogFor(0x36B0, 0x309F)
	if err != nil {
		t.Fatalf("resolveCatalogFor() error = %v", err)
	}
	if got := catalog.EffectName(intvia.ChannelRgbMatrix, 7); got != "my_chevron" {
		t.Errorf("EffectName(7) = %q, want the user's name", got)
	}
	if got := catalog.EffectSource(intvia.ChannelRgbMatrix, 7); got != intrgbSourceUser {
		t.Errorf("EffectSource(7) = %q, want %q", got, intrgbSourceUser)
	}
	// ID 8 is band_pinwheel_sat in the Impact 80's own file, and the user's file
	// said nothing about it, so it has to still be the vendor's name and carry no
	// source of its own.
	if got := catalog.EffectName(intvia.ChannelRgbMatrix, 8); got != "band_pinwheel_sat" {
		t.Errorf("EffectName(8) = %q, want the vendor's name left alone", got)
	}
	if got := catalog.EffectSource(intvia.ChannelRgbMatrix, 8); got != intrgbSourceVendor {
		t.Errorf("EffectSource(8) = %q, want an empty source for the vendor's", got)
	}
}

// intrgbLoadNamesFile and intrgbSourceUser keep the test reading through the
// internal package without importing it twice under two names.
func intrgbLoadNamesFile(path string) (*intrgb.Names, error) { return intrgb.LoadNamesFile(path) }

const (
	intrgbSourceUser   = intrgb.SourceUser
	intrgbSourceVendor = intrgb.SourceVendor
)