package voice

import (
	"context"
	"errors"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
)

// stubSTT 是一个返回固定结果的 mock STT。
type stubSTT struct {
	text string
	err  error
}

func (s *stubSTT) STT(_ context.Context, _ Audio) (string, error) { return s.text, s.err }

// stubTTS 是一个返回固定结果的 mock TTS。
type stubTTS struct {
	audio Audio
	err   error
}

func (s *stubTTS) TTS(_ context.Context, _ string) (Audio, error) { return s.audio, s.err }

// stubProvider 是携带可选方向的 mock Provider。
type stubProvider struct {
	name string
	stt  STT
	tts  TTS
}

func (s *stubProvider) Name() string { return s.name }
func (s *stubProvider) STT() STT     { return s.stt }
func (s *stubProvider) TTS() TTS     { return s.tts }

func TestChain_STT_Degrades(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name    string
		steps   []Provider
		want    string
		wantErr bool
	}{
		{
			name:  "first provider succeeds",
			steps: []Provider{&stubProvider{name: "cloud", stt: &stubSTT{text: "hello"}}},
			want:  "hello",
		},
		{
			name: "first fails second succeeds",
			steps: []Provider{
				&stubProvider{name: "cloud", stt: &stubSTT{err: ErrNotConfigured}},
				&stubProvider{name: "local", stt: &stubSTT{text: "degraded"}},
			},
			want: "degraded",
		},
		{
			name: "nil direction skipped",
			steps: []Provider{
				&stubProvider{name: "edge", stt: nil},
				&stubProvider{name: "silent", stt: &stubSTT{text: "silence"}},
			},
			want: "silence",
		},
		{
			name: "all fail no silent -> error",
			steps: []Provider{
				&stubProvider{name: "cloud", stt: &stubSTT{err: ErrNotConfigured}},
			},
			wantErr: true,
		},
		{
			name: "all fail silent last -> no error",
			steps: []Provider{
				&stubProvider{name: "cloud", stt: &stubSTT{err: ErrNotConfigured}},
				SilentProvider(),
			},
			want: "",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()
			got, err := NewChain(tt.steps...).STT(context.Background(), Audio{Format: "wav", Data: []byte("x")})
			if tt.wantErr {
				if !errors.Is(err, ErrProviderFailed) {
					t.Fatalf("err = %v, want ErrProviderFailed", err)
				}
				return
			}
			if err != nil {
				t.Fatalf("STT error: %v", err)
			}
			if got != tt.want {
				t.Errorf("text = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestChain_TTS_Degrades(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name    string
		steps   []Provider
		want    Audio
		wantErr bool
	}{
		{
			name:  "first provider succeeds",
			steps: []Provider{&stubProvider{name: "cloud", tts: &stubTTS{audio: Audio{Format: "mp3", Data: []byte("a")}}}},
			want:  Audio{Format: "mp3", Data: []byte("a")},
		},
		{
			name: "first fails second succeeds",
			steps: []Provider{
				&stubProvider{name: "cloud", tts: &stubTTS{err: ErrNotConfigured}},
				&stubProvider{name: "edge-tts", tts: &stubTTS{audio: Audio{Format: "mp3", Data: []byte("b")}}},
			},
			want: Audio{Format: "mp3", Data: []byte("b")},
		},
		{
			name: "all fail no silent -> error",
			steps: []Provider{
				&stubProvider{name: "cloud", tts: &stubTTS{err: ErrNotConfigured}},
			},
			wantErr: true,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()
			got, err := NewChain(tt.steps...).TTS(context.Background(), "hi")
			if tt.wantErr {
				if !errors.Is(err, ErrProviderFailed) {
					t.Fatalf("err = %v, want ErrProviderFailed", err)
				}
				return
			}
			if err != nil {
				t.Fatalf("TTS error: %v", err)
			}
			if got.Format != tt.want.Format || string(got.Data) != string(tt.want.Data) {
				t.Errorf("audio = %+v, want %+v", got, tt.want)
			}
		})
	}
}

func TestChain_Empty(t *testing.T) {
	t.Parallel()
	if _, err := NewChain().STT(context.Background(), Audio{}); !errors.Is(err, ErrProviderFailed) {
		t.Fatalf("err = %v, want ErrProviderFailed", err)
	}
}

func TestNew_ConfigAssembly(t *testing.T) {
	t.Parallel()
	// 配了云端 key 且 TTS 默认走 edge-tts 时，链从 cloud 开始、
	// 到 silent 结束。
	c := New(config.VoiceConfig{DashscopeAPIKey: "k"})
	names := make([]string, 0, len(c.steps))
	for _, p := range c.steps {
		names = append(names, p.Name())
	}
	if len(names) < 2 || names[len(names)-1] != "silent" {
		t.Fatalf("steps = %v, want to end at silent", names)
	}
	if names[0] != "cloud" {
		t.Errorf("first step = %q, want cloud", names[0])
	}

	// 没有 key 时跳过云端一级。
	c2 := New(config.VoiceConfig{})
	foundCloud := false
	for _, p := range c2.steps {
		if p.Name() == "cloud" {
			foundCloud = true
		}
	}
	if foundCloud {
		t.Error("cloud step present without an API key")
	}
}