package main

import (
	"encoding/json"
	"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 the generated
// scaffold can be checked without hardware.
type generateStub struct {
	tops map[intvia.Channel]int
}

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

func stubGenerateTarget(t *testing.T, channels []intvia.Channel, tops map[intvia.Channel]int) {
	t.Helper()
	original := openTarget
	t.Cleanup(func() { openTarget = original })
	openTarget = func(string) (rgbProtocol, targetDeviceData, []intvia.Channel, error) {
		return generateStub{tops: tops}, stubTargetData(0x36B0, 0x309F), channels, nil
	}
}

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

// The whole point of the command: a generated file names no effect, so a board
// with a generated definition reports the same "no names" it reported before one
// existed. A scaffold that claimed names would be a guess the tool could not
// read back off the keyboard.
func TestGeneratedDefinitionNamesNoEffectUntilTheUserFillsItIn(t *testing.T) {
	dir := t.TempDir()
	t.Cleanup(definitionFlagRestore(t))
	t.Cleanup(forceDefinitionsDir(t, dir))
	t.Cleanup(forceGenerateRestore(t))
	stubGenerateTarget(t, []intvia.Channel{intvia.ChannelRgbMatrix}, map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45})

	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())
	}

	path := onlyDefinition(t, dir)
	def, err := intrgb.ParseDefinition(path, []byte(mustRead(t, path)))
	if err != nil {
		t.Fatalf("ParseDefinition(%s) error = %v; the generated file has to load", path, err)
	}
	if got := len(def.Catalog.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 states which
	// IDs exist and leaves the naming to the user.
	var file struct {
		Menus []struct {
			Content []struct {
				Label   string `json:"label"`
				Type    string `json:"type"`
				Content []any  `json:"content"`
				Options []any  `json:"options"`
			} `json:"content"`
		} `json:"menus"`
	}
	if err := json.Unmarshal([]byte(mustRead(t, path)), &file); err != nil {
		t.Fatalf("unmarshal generated file: %v", err)
	}
	var options []any
	for _, menu := range file.Menus {
		for _, entry := range menu.Content {
			if entry.Type == "dropdown" {
				options = entry.Options
			}
		}
	}
	if len(options) != 46 {
		t.Fatalf("effect options = %d, want 46, one per ID from 0 to 45", len(options))
	}
	for i, option := range options {
		pair, ok := option.([]any)
		if !ok || len(pair) != 2 {
			t.Fatalf("option %d = %v, want a name and a number", i, option)
		}
		if name, _ := pair[0].(string); name != "" {
			t.Errorf("option %d is named %q, want a slot with no name", i, name)
		}
		if number, _ := pair[1].(float64); int(number) != i {
			t.Errorf("option %d carries ID %v, want the slot numbered %d", i, pair[1], i)
		}
	}

	// Every control has to be addressed by a value key the parser recognises. A
	// key built by trimming a suffix and appending without the underscore is
	// `id_qmk_rgb_matrixbrightness`, which names nothing, and nothing in the
	// output above would say so.
	wantKeys := map[string]bool{
		"id_qmk_rgb_matrix_brightness":   false,
		"id_qmk_rgb_matrix_effect":       false,
		"id_qmk_rgb_matrix_effect_speed": false,
	}
	for _, menu := range file.Menus {
		for _, entry := range menu.Content {
			key, _ := entry.Content[0].(string)
			if _, ok := wantKeys[key]; !ok {
				t.Errorf("control %q is addressed by %q, which is not a VIA value key", entry.Label, key)
				continue
			}
			wantKeys[key] = true
		}
	}
	for key, found := range wantKeys {
		if !found {
			t.Errorf("no control addresses %q", key)
		}
	}
}

// A definition a user has written is the one command they would have run to write
// it, so it must survive a second run of the command.
func TestGenerateDoesNotReplaceAStoredDefinition(t *testing.T) {
	dir := t.TempDir()
	t.Cleanup(definitionFlagRestore(t))
	t.Cleanup(forceDefinitionsDir(t, dir))
	t.Cleanup(forceGenerateRestore(t))
	stubGenerateTarget(t, []intvia.Channel{intvia.ChannelRgbMatrix}, map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45})

	written := `{"name":"Test Board","vendorId":"0x36B0","productId":"0x309F","menus":[],"note":"hand written"}`
	if err := os.WriteFile(filepath.Join(dir, "test_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 definition")
	}
	if !strings.Contains(err.Error(), "--force") {
		t.Errorf("error = %q, want it to offer --force", err)
	}
	if got := mustRead(t, filepath.Join(dir, "test_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
// hold them: 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 := t.TempDir()
	t.Cleanup(definitionFlagRestore(t))
	t.Cleanup(forceDefinitionsDir(t, dir))
	t.Cleanup(forceGenerateRestore(t))
	stubGenerateTarget(t, []intvia.Channel{intvia.ChannelRgbMatrix}, map[intvia.Channel]int{intvia.ChannelRgbMatrix: 45})

	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", err)
	}

	note := mustRead(t, strings.TrimSuffix(onlyDefinition(t, dir), ".json")+spottedNoteSuffix)
	if !strings.Contains(note, "rgb_matrix (channel 3), IDs 0 to 45") {
		t.Errorf("note = %q, want it to name the channel and the ID range", note)
	}
	// The measurement behind the names: a spelling, how many boards wrote it, and
	// which manufacturer most of them were.
	if !strings.Contains(note, "rainbow_moving_chevron") {
		t.Errorf("note = %q, want the spellings other definitions use", note)
	}
	if !strings.Contains(note, "boards:") {
		t.Errorf("note = %q, want a count of boards next to every name", note)
	}
	if !strings.Contains(note, "keychron") {
		t.Errorf("note = %q, want the manufacturer behind most of a name's spellings", note)
	}
	// Effect 23 is where the collection disagrees about what the number even is,
	// so the note has to show the runner-up rather than pick a winner.
	if !strings.Contains(note, "ID 23 ") {
		t.Errorf("note = %q, want a line for ID 23", note)
	}
}

func onlyDefinition(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("definitions dir = %v, want one JSON 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)
}