package stt

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"

	"go.uber.org/zap"
)

func newTestMiMoService(handler http.HandlerFunc) (*MiMoService, *httptest.Server) {
	srv := httptest.NewServer(handler)
	s := NewMiMoService("test-key", "mimo-v2.5-asr", srv.URL, zap.NewNop().Sugar())
	return s, srv
}

func TestMiMoService_Recognize_Success(t *testing.T) {
	s, srv := newTestMiMoService(func(w http.ResponseWriter, r *http.Request) {
		// 验证请求
		if r.Header.Get("Authorization") != "Bearer test-key" {
			t.Errorf("expected Authorization Bearer test-key, got %s", r.Header.Get("Authorization"))
		}
		if r.URL.Path != "/chat/completions" {
			t.Errorf("expected path /chat/completions, got %s", r.URL.Path)
		}

		var req mimoRequest
		body, _ := io.ReadAll(r.Body)
		if err := json.Unmarshal(body, &req); err != nil {
			t.Fatalf("unmarshal request: %v", err)
		}
		if req.Model != "mimo-v2.5-asr" {
			t.Errorf("expected model mimo-v2.5-asr, got %s", req.Model)
		}
		if len(req.Messages) == 0 || req.Messages[0].Role != "user" {
			t.Error("expected user message")
		}
		if req.ASROptions == nil || req.ASROptions.Language != "zh" {
			t.Errorf("expected language zh, got %v", req.ASROptions)
		}

		resp := mimoResponse{
			Choices: []struct {
				Message struct {
					Content string `json:"content"`
				} `json:"message"`
			}{
				{Message: struct {
					Content string `json:"content"`
				}{Content: "你好世界"}},
			},
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(resp)
	})
	defer srv.Close()

	// 发送一个简单的有效 WAV（44 字节头 + 少量 PCM）
	wav := makeValidWAV([]byte{0x00, 0x00, 0x00, 0x00})
	text, err := s.Recognize(context.Background(), wav, Options{Language: "zh-CN"})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if text != "你好世界" {
		t.Errorf("expected '你好世界', got '%s'", text)
	}
}

func TestMiMoService_Recognize_EmptyAudio(t *testing.T) {
	s, srv := newTestMiMoService(func(w http.ResponseWriter, r *http.Request) {})
	defer srv.Close()

	_, err := s.Recognize(context.Background(), nil, Options{})
	if err == nil {
		t.Fatal("expected error for empty audio")
	}
}

func TestMiMoService_Recognize_ServerError(t *testing.T) {
	s, srv := newTestMiMoService(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("internal error"))
	})
	defer srv.Close()

	wav := makeValidWAV([]byte{0x00, 0x00})
	_, err := s.Recognize(context.Background(), wav, Options{})
	if err == nil {
		t.Fatal("expected error for 500 response")
	}
}

func TestMiMoService_Recognize_EmptyChoices(t *testing.T) {
	s, srv := newTestMiMoService(func(w http.ResponseWriter, r *http.Request) {
		resp := mimoResponse{Choices: nil}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(resp)
	})
	defer srv.Close()

	wav := makeValidWAV([]byte{0x00, 0x00})
	_, err := s.Recognize(context.Background(), wav, Options{})
	if err == nil {
		t.Fatal("expected error for empty choices")
	}
}

func TestMiMoService_Recognize_PCMAutoWrap(t *testing.T) {
	// 测试原始 PCM 数据自动封装为 WAV
	s, srv := newTestMiMoService(func(w http.ResponseWriter, r *http.Request) {
		var req mimoRequest
		body, _ := io.ReadAll(r.Body)
		if err := json.Unmarshal(body, &req); err != nil {
			t.Fatalf("unmarshal request: %v", err)
		}

		// 验证 data URL 格式
		if len(req.Messages) == 0 || len(req.Messages[0].Content) == 0 {
			t.Fatal("empty message content")
		}
		dataURL := req.Messages[0].Content[0].InputAudio.Data
		if len(dataURL) < 22 || dataURL[:14] != "data:audio/wav" {
			t.Errorf("expected wav data URL, got prefix: %s", dataURL[:min(len(dataURL), 30)])
		}

		// 验证 base64 可解码
		b64Part := dataURL[22:] // skip "data:audio/wav;base64,"
		decoded, err := base64.StdEncoding.DecodeString(b64Part)
		if err != nil {
			t.Fatalf("base64 decode failed: %v", err)
		}
		// 应该是有效 WAV（RIFF 头）
		if len(decoded) < 44 || string(decoded[:4]) != "RIFF" {
			t.Error("decoded data is not a valid WAV")
		}

		resp := mimoResponse{
			Choices: []struct {
				Message struct {
					Content string `json:"content"`
				} `json:"message"`
			}{
				{Message: struct {
					Content string `json:"content"`
				}{Content: "test"}},
			},
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(resp)
	})
	defer srv.Close()

	// 发送原始 PCM（非 WAV/MP3）
	pcm := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07}
	text, err := s.Recognize(context.Background(), pcm, Options{SampleRate: 16000})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if text != "test" {
		t.Errorf("expected 'test', got '%s'", text)
	}
}

func TestMapLanguage(t *testing.T) {
	tests := []struct {
		input string
		want  string
	}{
		{"", "auto"},
		{"zh-CN", "zh"},
		{"zh", "zh"},
		{"en-US", "en"},
		{"en", "en"},
		{"ja", "auto"},
	}
	for _, tt := range tests {
		got := mapLanguage(tt.input)
		if got != tt.want {
			t.Errorf("mapLanguage(%q) = %q, want %q", tt.input, got, tt.want)
		}
	}
}

func TestIsWAV(t *testing.T) {
	if !isWAV([]byte("RIFF....")) {
		t.Error("expected true for RIFF header")
	}
	if isWAV([]byte("ID3...")) {
		t.Error("expected false for ID3 header")
	}
	if isWAV([]byte{0x00}) {
		t.Error("expected false for short data")
	}
}

func TestIsMP3(t *testing.T) {
	if !isMP3([]byte("ID3\x03")) {
		t.Error("expected true for ID3 header")
	}
	if !isMP3([]byte{0xFF, 0xFB, 0x00}) {
		t.Error("expected true for MP3 sync word")
	}
	if isMP3([]byte("RIFF")) {
		t.Error("expected false for RIFF header")
	}
}

func makeValidWAV(pcm []byte) []byte {
	// 构造一个最小有效 WAV
	wav := make([]byte, 44+len(pcm))
	copy(wav[:4], "RIFF")
	// little-endian size = 36 + len(pcm)
	size := uint32(36 + len(pcm))
	wav[4] = byte(size)
	wav[5] = byte(size >> 8)
	wav[6] = byte(size >> 16)
	wav[7] = byte(size >> 24)
	copy(wav[8:12], "WAVE")
	copy(wav[12:16], "fmt ")
	// fmt chunk size = 16
	wav[16] = 16
	// PCM format = 1
	wav[20] = 1
	// channels = 1
	wav[22] = 1
	// sample rate = 16000
	wav[24] = 0x80
	wav[25] = 0x3E
	// byte rate = 32000
	wav[28] = 0x00
	wav[29] = 0x7D
	// block align = 2
	wav[32] = 2
	// bits per sample = 16
	wav[34] = 16
	copy(wav[36:40], "data")
	dSize := uint32(len(pcm))
	wav[40] = byte(dSize)
	wav[41] = byte(dSize >> 8)
	wav[42] = byte(dSize >> 16)
	wav[43] = byte(dSize >> 24)
	copy(wav[44:], pcm)
	return wav
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}