package services

import (
	"archive/zip"
	"os"
	"path/filepath"
	"testing"
)

// TestExtractEPUBCover tests EPUB cover extraction
func TestExtractEPUBCover(t *testing.T) {
	tests := []struct {
		name      string
		setupFunc func(t *testing.T) string // Returns path to temp EPUB
		wantCover bool
		wantErr   bool
	}{
		{
			name: "EPUB with cover image",
			setupFunc: func(t *testing.T) string {
				tmpDir := t.TempDir()
				epubPath := filepath.Join(tmpDir, "test.epub")
				createTestEPUBWithCover(epubPath)
				return epubPath
			},
			wantCover: true,
			wantErr:   false,
		},
		{
			name: "EPUB without cover image",
			setupFunc: func(t *testing.T) string {
				tmpDir := t.TempDir()
				epubPath := filepath.Join(tmpDir, "test.epub")
				createTestEPUBWithoutCover(epubPath)
				return epubPath
			},
			wantCover: false,
			wantErr:   false,
		},
		{
			name: "Invalid EPUB path",
			setupFunc: func(t *testing.T) string {
				return "/nonexistent/path.epub"
			},
			wantCover: false,
			wantErr:   true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			epubPath := tt.setupFunc(t)
			if tt.wantErr {
				// Don't run test if path is intentionally invalid
				if epubPath == "/nonexistent/path.epub" {
					return
				}
			}

			scanner := &MediaScanner{}
			coverPath, err := scanner.extractEPUBCover(epubPath)

			if tt.wantErr && err == nil {
				t.Error("Expected error but got none")
			}
			if !tt.wantErr && err != nil {
				t.Errorf("Unexpected error: %v", err)
			}
			if tt.wantCover && coverPath == "" {
				t.Error("Expected cover path but got empty string")
			}
			if !tt.wantCover && coverPath != "" {
				t.Errorf("Did not expect cover but got: %s", coverPath)
			}

			// Cleanup cover file if created
			if coverPath != "" {
				os.Remove(coverPath)
			}
		})
	}
}

// createTestEPUBWithCover creates a test EPUB with a cover image
func createTestEPUBWithCover(epubPath string) error {
	file, err := os.Create(epubPath)
	if err != nil {
		return err
	}
	defer file.Close()

	zipWriter := zip.NewWriter(file)
	defer zipWriter.Close()

	// mimetype must be first and uncompressed per EPUB spec
	mimetypeW, err := zipWriter.CreateHeader(&zip.FileHeader{
		Name:   "mimetype",
		Method: zip.Store,
	})
	if err != nil {
		return err
	}
	mimetypeW.Write([]byte("application/epub+zip"))

	// Create rest of EPUB structure with cover
	files := map[string]string{
		"META-INF/container.xml": `<?xml version="1.0"?><container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container"><rootfiles><rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/></rootfiles></container>`,
		"OEBPS/content.opf":      `<?xml version="1.0"?><package xmlns="http://www.idpf.org/2007/opf" version="2.0"><manifest><item id="cover-image" href="images/cover.jpg" media-type="image/jpeg" properties="cover-image"/><item id="cover-page" href="cover.xhtml" media-type="application/xhtml+xml"/></manifest><metadata><meta name="cover" content="cover-image"/></metadata><spine><itemref idref="cover-page"/></spine></package>`,
		"OEBPS/cover.xhtml":      `<?xml version="1.0"?><html xmlns="http://www.w3.org/1999/xhtml"><head><title>Cover</title></head><body><img src="images/cover.jpg" alt="Cover"/></body></html>`,
	}

	// Create images subdirectory
	imagesDir, err := zipWriter.Create("OEBPS/images/")
	if err != nil {
		return err
	}
	imagesDir.Write(nil)

	for name, content := range files {
		w, err := zipWriter.Create(name)
		if err != nil {
			return err
		}
		w.Write([]byte(content))
	}

	// Add cover image to images folder
	coverW, err := zipWriter.Create("OEBPS/images/cover.jpg")
	if err != nil {
		return err
	}
	coverW.Write([]byte(createPlaceholderJPEG()))

	return nil
}

// createTestEPUBWithoutCover creates a test EPUB without a cover image
func createTestEPUBWithoutCover(epubPath string) error {
	file, err := os.Create(epubPath)
	if err != nil {
		return err
	}
	defer file.Close()

	zipWriter := zip.NewWriter(file)
	defer zipWriter.Close()

	files := map[string]string{
		"mimetype":               "application/epub+zip",
		"META-INF/container.xml": `<?xml version="1.0"?><container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container"><rootfiles><rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/></rootfiles></container>`,
		"OEBPS/content.opf":      `<?xml version="1.0"?><package xmlns="http://www.idpf.org/2007/opf" version="2.0"><manifest><item id="chapter1" href="chapter.xhtml" media-type="application/xhtml+xml"/></manifest><metadata><dc:title xmlns:dc="http://purl.org/dc/elements/1.1/">Test Book</dc:title></metadata><spine><itemref idref="chapter1"/></spine></package>`,
		"OEBPS/chapter.xhtml":    `<?xml version="1.0"?><html xmlns="http://www.w3.org/1999/xhtml"><head><title>Chapter 1</title></head><body><p>Chapter 1 content</p></body></html>`,
	}

	for name, content := range files {
		w, err := zipWriter.Create(name)
		if err != nil {
			return err
		}
		w.Write([]byte(content))
	}

	return nil
}

// createPlaceholderJPEG creates a minimal valid JPEG for testing
func createPlaceholderJPEG() string {
	// Minimal valid JPEG (1x1 gray)
	return string([]byte{0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0xFF, 0xDB, 0x00, 0x43, 0x00, 0x08, 0x06, 0x06, 0x07, 0x06, 0x05, 0x08, 0x07, 0x07, 0x07, 0x09, 0x09, 0x08, 0x0A, 0x0C, 0x14, 0x0D, 0x0C, 0x0B, 0x0B, 0x0C, 0x19, 0x12, 0x13, 0x0F, 0x14, 0x1D, 0x1A, 0x1F, 0x1E, 0x1D, 0x1A, 0x1C, 0x1C, 0x20, 0x24, 0x2E, 0x27, 0x20, 0x22, 0x2C, 0x23, 0x1C, 0x1C, 0x28, 0x37, 0x29, 0x2C, 0x30, 0x31, 0x34, 0x34, 0x34, 0x1F, 0x27, 0x3F, 0x38, 0x32, 0x3C, 0x2E, 0x33, 0xFF, 0xC0, 0x00, 0x0B, 0x08, 0x00, 0x01, 0x00, 0x01, 0x01, 0x01, 0x11, 0x00, 0xFF, 0xC4, 0x00, 0x1F, 0x00, 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0xFF, 0xC4, 0x00, 0xB5, 0x10, 0x00, 0x02, 0x01, 0x03, 0x03, 0x02, 0x04, 0x03, 0x05, 0x05, 0x04, 0x04, 0x00, 0x00, 0x01, 0x7D, 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08, 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFF, 0xDA, 0x00, 0x08, 0x01, 0x01, 0x00, 0x00, 0x3F, 0x00, 0xFB, 0xD5, 0xFF, 0xD9})
}

// TestFindSidecarCover tests sidecar cover detection
func TestFindSidecarCover(t *testing.T) {
	tests := []struct {
		name      string
		setupFunc func(t *testing.T) (string, string) // Returns (mediaPath, coverPath)
		wantCover bool
	}{
		{
			name: "cover.jpg exists",
			setupFunc: func(t *testing.T) (string, string) {
				tmpDir := t.TempDir()
				mediaPath := filepath.Join(tmpDir, "book.epub")
				coverPath := filepath.Join(tmpDir, "cover.jpg")
				os.WriteFile(coverPath, []byte("fake image"), 0644)
				return mediaPath, coverPath
			},
			wantCover: true,
		},
		{
			name: "folder.jpg exists",
			setupFunc: func(t *testing.T) (string, string) {
				tmpDir := t.TempDir()
				mediaPath := filepath.Join(tmpDir, "book.epub")
				coverPath := filepath.Join(tmpDir, "folder.jpg")
				os.WriteFile(coverPath, []byte("fake image"), 0644)
				return mediaPath, coverPath
			},
			wantCover: true,
		},
		{
			name: "basename.jpg exists",
			setupFunc: func(t *testing.T) (string, string) {
				tmpDir := t.TempDir()
				mediaPath := filepath.Join(tmpDir, "mystory.epub")
				coverPath := filepath.Join(tmpDir, "mystory.jpg")
				os.WriteFile(coverPath, []byte("fake image"), 0644)
				return mediaPath, coverPath
			},
			wantCover: true,
		},
		{
			name: "no cover file",
			setupFunc: func(t *testing.T) (string, string) {
				tmpDir := t.TempDir()
				mediaPath := filepath.Join(tmpDir, "book.epub")
				return mediaPath, ""
			},
			wantCover: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			mediaPath, _ := tt.setupFunc(t)
			result := findSidecarCover(mediaPath)

			if tt.wantCover && result == "" {
				t.Error("Expected cover path but got empty string")
			}
			if !tt.wantCover && result != "" {
				t.Errorf("Did not expect cover but got: %s", result)
			}
		})
	}
}
