package sync

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

func TestSyncLyrics(t *testing.T) {
	// Create temporary test directory
	tempDir := t.TempDir()

	// Test cases for different format combinations
	testCases := []struct {
		name           string
		sourceContent  string
		sourceExt      string
		targetContent  string
		targetExt      string
		expectedError  bool
		validateOutput func(t *testing.T, filePath string)
	}{
		{
			name: "LRC to LRC sync",
			sourceContent: `[ti:Source LRC]
[ar:Test Artist]

[00:01.00]This is line one.
[00:05.00]This is line two.
[00:09.50]This is line three.
`,
			sourceExt: "lrc",
			targetContent: `[ti:Target LRC]
[ar:Different Artist]

[00:10.00]This is line one with different timing.
[00:20.00]This is line two with different timing.
[00:30.00]This is line three with different timing.
`,
			targetExt:     "lrc",
			expectedError: false,
			validateOutput: func(t *testing.T, filePath string) {
				content, err := os.ReadFile(filePath)
				if err != nil {
					t.Fatalf("Failed to read output file: %v", err)
				}

				contentStr := string(content)

				// Should contain target title but source timings
				if !strings.Contains(contentStr, "[ti:Target LRC]") {
					t.Errorf("Output should preserve target title, got: %s", contentStr)
				}
				if !strings.Contains(contentStr, "[ar:Different Artist]") {
					t.Errorf("Output should preserve target artist, got: %s", contentStr)
				}

				// Should have source timings
				if !strings.Contains(contentStr, "[00:01.000]") {
					t.Errorf("Output should have source timing [00:01.000], got: %s", contentStr)
				}

				// Should have target content
				if !strings.Contains(contentStr, "This is line one with different timing.") {
					t.Errorf("Output should preserve target content, got: %s", contentStr)
				}
			},
		},
		{
			name: "SRT to SRT sync",
			sourceContent: `1
00:00:01,000 --> 00:00:04,000
This is line one.

2
00:00:05,000 --> 00:00:08,000
This is line two.

3
00:00:09,000 --> 00:00:12,000
This is line three.
`,
			sourceExt: "srt",
			targetContent: `1
00:01:00,000 --> 00:01:03,000
This is target line one.

2
00:01:05,000 --> 00:01:08,000
This is target line two.

3
00:01:10,000 --> 00:01:13,000
This is target line three.
`,
			targetExt:     "srt",
			expectedError: false,
			validateOutput: func(t *testing.T, filePath string) {
				content, err := os.ReadFile(filePath)
				if err != nil {
					t.Fatalf("Failed to read output file: %v", err)
				}

				contentStr := string(content)

				// Should have source timings but target content
				if !strings.Contains(contentStr, "00:00:01,000 -->") {
					t.Errorf("Output should have source timing 00:00:01,000, got: %s", contentStr)
				}

				// Check target content is preserved
				if !strings.Contains(contentStr, "This is target line one.") {
					t.Errorf("Output should preserve target content, got: %s", contentStr)
				}

				// Check identifiers are sequential
				if !strings.Contains(contentStr, "1\n00:00:01,000") {
					t.Errorf("Output should have sequential identifiers starting with 1, got: %s", contentStr)
				}
			},
		},
		{
			name: "VTT to VTT sync",
			sourceContent: `WEBVTT

1
00:00:01.000 --> 00:00:04.000
This is line one.

2
00:00:05.000 --> 00:00:08.000
This is line two.

3
00:00:09.000 --> 00:00:12.000
This is line three.
`,
			sourceExt: "vtt",
			targetContent: `WEBVTT - Target Title

1
00:01:00.000 --> 00:01:03.000 align:start position:10%
This is target line one.

2
00:01:05.000 --> 00:01:08.000 align:middle
This is target line two.

3
00:01:10.000 --> 00:01:13.000
This is target line three.
`,
			targetExt:     "vtt",
			expectedError: false,
			validateOutput: func(t *testing.T, filePath string) {
				content, err := os.ReadFile(filePath)
				if err != nil {
					t.Fatalf("Failed to read output file: %v", err)
				}

				contentStr := string(content)

				// Should preserve VTT title
				if !strings.Contains(contentStr, "WEBVTT - Target Title") {
					t.Errorf("Output should preserve target title, got: %s", contentStr)
				}

				// Should have source timings but target content and settings
				if !strings.Contains(contentStr, "00:00:01.000 -->") {
					t.Errorf("Output should have source timing 00:00:01.000, got: %s", contentStr)
				}

				// Should preserve styling cue settings
				if !strings.Contains(contentStr, "align:start position:10%") {
					t.Errorf("Output should preserve cue settings, got: %s", contentStr)
				}

				// Check target content is preserved
				if !strings.Contains(contentStr, "This is target line one.") {
					t.Errorf("Output should preserve target content, got: %s", contentStr)
				}
			},
		},
		{
			name: "ASS to ASS sync",
			sourceContent: `[Script Info]
ScriptType: v4.00+
PlayResX: 640
PlayResY: 480
Timer: 100.0000
Title: Source ASS File

[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Source line one.
Dialogue: 0,0:00:05.00,0:00:08.00,Default,,0,0,0,,Source line two.
Dialogue: 0,0:00:09.00,0:00:12.00,Default,,0,0,0,,Source line three.
`,
			sourceExt: "ass",
			targetContent: `[Script Info]
ScriptType: v4.00+
PlayResX: 640
PlayResY: 480
Timer: 100.0000
Title: Target ASS File

[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1
Style: Alternate,Arial,20,&H0000FFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:01:00.00,0:01:03.00,Default,,0,0,0,,Target line one.
Dialogue: 0,0:01:05.00,0:01:08.00,Alternate,,0,0,0,,Target line two.
Dialogue: 0,0:01:10.00,0:01:13.00,Default,,0,0,0,,Target line three.
`,
			targetExt:     "ass",
			expectedError: false,
			validateOutput: func(t *testing.T, filePath string) {
				content, err := os.ReadFile(filePath)
				if err != nil {
					t.Fatalf("Failed to read output file: %v", err)
				}

				contentStr := string(content)

				// Should have source timings but target content
				if !strings.Contains(contentStr, "0:00:01.00") {
					t.Errorf("Output should have source timing 0:00:01.00, got: %s", contentStr)
				}

				// Check target content is preserved
				if !strings.Contains(contentStr, "Target line one.") {
					t.Errorf("Output should preserve target content, got: %s", contentStr)
				}

				// Check target styles are preserved
				if !strings.Contains(contentStr, "Style: Alternate") {
					t.Errorf("Output should preserve target styles, got: %s", contentStr)
				}

				// Check target title is preserved
				if !strings.Contains(contentStr, "Title: Target ASS File") {
					t.Errorf("Output should preserve target title, got: %s", contentStr)
				}
			},
		},
		{
			name:          "Unsupported format combination",
			sourceContent: `[00:01.00]This is line one.`,
			sourceExt:     "lrc",
			targetContent: `1\n00:00:01,000 --> 00:00:04,000\nThis is line one.`,
			targetExt:     "srt",
			expectedError: true,
			validateOutput: func(t *testing.T, filePath string) {
				// Not needed for error case
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
sourceFile := filepath.Join(tempDir, "source."+tc.sourceExt)
targetFile := filepath.Join(tempDir, "target."+tc.targetExt)

// Write test files
if err := os.WriteFile(sourceFile, []byte(tc.sourceContent), 0644); err != nil {
				t.Fatalf("Failed to write source file: %v", err)
			}

			if err := os.WriteFile(targetFile, []byte(tc.targetContent), 0644); err != nil {
				t.Fatalf("Failed to write target file: %v", err)
			}

			// Run SyncLyrics
			err := SyncLyrics(sourceFile, targetFile)

			// Check error status
			if tc.expectedError && err == nil {
				t.Errorf("Expected error but got nil")
			} else if !tc.expectedError && err != nil {
				t.Errorf("Unexpected error: %v", err)
			}

			// If no error is expected, validate the output
			if !tc.expectedError && err == nil {
				tc.validateOutput(t, targetFile)
			}
		})
	}
}