package main

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
)

// TestISBNNormalization tests ISBN normalization with various formats
func TestISBNNormalization(t *testing.T) {
	t.Run("ISBN-13 with hyphens should be normalized", func(t *testing.T) {
		// Test cases for ISBN-13 with various hyphen placements
		testCases := []struct {
			name     string
			input    string
			expected string
		}{
			{
				name:     "ISBN-13 with hyphens (978-0-12345-678-9)",
				input:    "978-0-12345-678-9",
				expected: "9780123456789",
			},
			{
				name:     "ISBN-13 with single hyphen (978-0123456789)",
				input:    "978-0123456789",
				expected: "9780123456789",
			},
			{
				name:     "ISBN-13 without hyphens",
				input:    "9780123456789",
				expected: "9780123456789",
			},
			{
				name:     "ISBN-13 with spaces",
				input:    "978 0123456789",
				expected: "9780123456789",
			},
			{
				name:     "ISBN-13 with mixed hyphens and spaces",
				input:    "978-0 1234-56789",
				expected: "9780123456789",
			},
			{
				name:     "ISBN-10 with hyphens",
				input:    "0-12345-678-9",
				expected: "0123456789",
			},
			{
				name:     "ISBN-10 without hyphens",
				input:    "0123456789",
				expected: "0123456789",
			},
			{
				name:     "ISBN-10 with X",
				input:    "0-12345-678-X",
				expected: "012345678X",
			},
		}

		for _, tc := range testCases {
			t.Run(tc.name, func(t *testing.T) {
				payload := map[string]interface{}{
					"title":     "Test Ebook",
					"isbn":      tc.input,
					"file_path": "/path/to/file.epub",
					"file_size": 1024,
					"mime_type": "application/epub+zip",
				}
				jsonData, _ := json.Marshal(payload)

				req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
				req.Header.Set("Content-Type", "application/json")
				req.Header.Set("Authorization", "Bearer admin-token")
				req.Header.Set("X-User-Role", "admin")
				req.Header.Set("X-User-Id", uuid.New().String())
				rr := httptest.NewRecorder()

				handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					// Simulate successful creation with normalized ISBN
					w.WriteHeader(http.StatusCreated)
					response := map[string]interface{}{
						"id":    uuid.New().String(),
						"title": "Test Ebook",
						"isbn":  tc.expected,
					}
					json.NewEncoder(w).Encode(response)
				})

				handler.ServeHTTP(rr, req)

				assert.Equal(t, http.StatusCreated, rr.Code)

				var response map[string]interface{}
				json.Unmarshal(rr.Body.Bytes(), &response)
				assert.Equal(t, tc.expected, response["isbn"])
			})
		}
	})

	t.Run("Empty ISBN should be handled", func(t *testing.T) {
		payload := map[string]interface{}{
			"title":     "Test Ebook",
			"file_path": "/path/to/file.epub",
			"file_size": 1024,
			"mime_type": "application/epub+zip",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusCreated)
		})

		handler.ServeHTTP(rr, req)
		assert.Equal(t, http.StatusCreated, rr.Code)
	})

	t.Run("Invalid ISBN format should still be stored as-is", func(t *testing.T) {
		// Test that very short or obviously invalid ISBNs are still accepted
		// The database function will normalize what it can
		testCases := []struct {
			name  string
			isbn  string
			valid bool
		}{
			{"Too short ISBN", "123", true},
			{"Valid ISBN-13", "9780123456789", true},
			{"Valid ISBN-10", "0123456789", true},
		}

		for _, tc := range testCases {
			t.Run(tc.name, func(t *testing.T) {
				payload := map[string]interface{}{
					"title":     "Test Ebook",
					"isbn":      tc.isbn,
					"file_path": "/path/to/file.epub",
					"file_size": 1024,
					"mime_type": "application/epub+zip",
				}
				jsonData, _ := json.Marshal(payload)

				req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
				req.Header.Set("Content-Type", "application/json")
				req.Header.Set("Authorization", "Bearer admin-token")
				req.Header.Set("X-User-Role", "admin")
				rr := httptest.NewRecorder()

				handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					if tc.valid {
						w.WriteHeader(http.StatusCreated)
					} else {
						w.WriteHeader(http.StatusBadRequest)
					}
				})

				handler.ServeHTTP(rr, req)

				if tc.valid {
					assert.Equal(t, http.StatusCreated, rr.Code)
				} else {
					assert.Equal(t, http.StatusBadRequest, rr.Code)
				}
			})
		}
	})
}

// TestEbookLibraryRequirement tests that ebooks require an existing library
func TestEbookLibraryRequirement(t *testing.T) {
	t.Run("Create ebook without any libraries should fail gracefully", func(t *testing.T) {
		payload := map[string]interface{}{
			"title":     "Test Ebook",
			"isbn":      "978-0123456789",
			"file_path": "/path/to/file.epub",
			"file_size": 1024,
			"mime_type": "application/epub+zip",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		req.Header.Set("X-User-Id", uuid.New().String())
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Simulate no library found scenario
			w.WriteHeader(http.StatusBadRequest)
			w.Write([]byte(`{"error":"no ebook library found. Please create an ebook library first"}`))
		})

		handler.ServeHTTP(rr, req)

		assert.Equal(t, http.StatusBadRequest, rr.Code)
		assert.Contains(t, rr.Body.String(), "no ebook library found")
	})

	t.Run("Create ebook with existing library should succeed", func(t *testing.T) {
		libraryID := uuid.New()
		payload := map[string]interface{}{
			"title":     "Test Ebook",
			"isbn":      "978-0123456789",
			"file_path": "/path/to/file.epub",
			"file_size": 1024,
			"mime_type": "application/epub+zip",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		req.Header.Set("X-User-Id", uuid.New().String())
		req.Header.Set("X-Library-Id", libraryID.String())
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Simulate successful creation
			w.WriteHeader(http.StatusCreated)
			response := map[string]interface{}{
				"id":         uuid.New().String(),
				"title":      "Test Ebook",
				"isbn":       "9780123456789",
				"library_id": libraryID.String(),
			}
			json.NewEncoder(w).Encode(response)
		})

		handler.ServeHTTP(rr, req)

		assert.Equal(t, http.StatusCreated, rr.Code)

		var response map[string]interface{}
		json.Unmarshal(rr.Body.Bytes(), &response)
		assert.Equal(t, "9780123456789", response["isbn"])
		assert.Equal(t, libraryID.String(), response["library_id"])
	})

	t.Run("Update ebook with normalized ISBN", func(t *testing.T) {
		ebookID := uuid.New()
		payload := map[string]interface{}{
			"title": "Updated Ebook",
			"isbn":  "978-987654321-0",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("PUT", "/api/ebooks/"+ebookID.String(), bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
			response := map[string]interface{}{
				"id":    ebookID.String(),
				"title": "Updated Ebook",
				"isbn":  "9789876543210",
			}
			json.NewEncoder(w).Encode(response)
		})

		handler.ServeHTTP(rr, req)

		assert.Equal(t, http.StatusOK, rr.Code)

		var response map[string]interface{}
		json.Unmarshal(rr.Body.Bytes(), &response)
		assert.Equal(t, "9789876543210", response["isbn"])
	})
}

// TestISBNEdgeCases tests edge cases for ISBN handling
func TestISBNEdgeCases(t *testing.T) {
	t.Run("ISBN with special characters should be normalized", func(t *testing.T) {
		testCases := []struct {
			name     string
			input    string
			expected string
		}{
			{
				name:     "ISBN with multiple hyphens",
				input:    "978-0-123-45678-9",
				expected: "9780123456789",
			},
			{
				name:     "ISBN with trailing hyphen",
				input:    "9780123456789-",
				expected: "9780123456789",
			},
			{
				name:     "ISBN with leading hyphen",
				input:    "-9780123456789",
				expected: "9780123456789",
			},
			{
				name:     "ISBN with multiple spaces",
				input:    "978  0123456789",
				expected: "9780123456789",
			},
		}

		for _, tc := range testCases {
			t.Run(tc.name, func(t *testing.T) {
				payload := map[string]interface{}{
					"title":     "Test Ebook",
					"isbn":      tc.input,
					"file_path": "/path/to/file.epub",
					"file_size": 1024,
					"mime_type": "application/epub+zip",
				}
				jsonData, _ := json.Marshal(payload)

				req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
				req.Header.Set("Content-Type", "application/json")
				req.Header.Set("Authorization", "Bearer admin-token")
				req.Header.Set("X-User-Role", "admin")
				rr := httptest.NewRecorder()

				handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					w.WriteHeader(http.StatusCreated)
					response := map[string]interface{}{
						"id":    uuid.New().String(),
						"title": "Test Ebook",
						"isbn":  tc.expected,
					}
					json.NewEncoder(w).Encode(response)
				})

				handler.ServeHTTP(rr, req)

				assert.Equal(t, http.StatusCreated, rr.Code)

				var response map[string]interface{}
				json.Unmarshal(rr.Body.Bytes(), &response)
				assert.Equal(t, tc.expected, response["isbn"])
			})
		}
	})

	t.Run("ISBN length validation", func(t *testing.T) {
		testCases := []struct {
			name         string
			isbn         string
			shouldAccept bool
		}{
			{
				name:         "Empty ISBN",
				isbn:         "",
				shouldAccept: true,
			},
			{
				name:         "Valid ISBN-10",
				isbn:         "0123456789",
				shouldAccept: true,
			},
			{
				name:         "Valid ISBN-13",
				isbn:         "9780123456789",
				shouldAccept: true,
			},
			{
				name:         "ISBN-13 with hyphens",
				isbn:         "978-0-12345-678-9",
				shouldAccept: true,
			},
			{
				name:         "Maximum length (17 chars with hyphens)",
				isbn:         "978-0-12345-678-9",
				shouldAccept: true,
			},
		}

		for _, tc := range testCases {
			t.Run(tc.name, func(t *testing.T) {
				payload := map[string]interface{}{
					"title":     "Test Ebook",
					"isbn":      tc.isbn,
					"file_path": "/path/to/file.epub",
					"file_size": 1024,
					"mime_type": "application/epub+zip",
				}
				jsonData, _ := json.Marshal(payload)

				req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
				req.Header.Set("Content-Type", "application/json")
				req.Header.Set("Authorization", "Bearer admin-token")
				req.Header.Set("X-User-Role", "admin")
				rr := httptest.NewRecorder()

				handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					if tc.shouldAccept {
						w.WriteHeader(http.StatusCreated)
					} else {
						w.WriteHeader(http.StatusBadRequest)
					}
				})

				handler.ServeHTTP(rr, req)

				if tc.shouldAccept {
					assert.Equal(t, http.StatusCreated, rr.Code)
				} else {
					assert.Equal(t, http.StatusBadRequest, rr.Code)
				}
			})
		}
	})
}

// TestLibraryAutoSelection tests automatic library selection by resource type
func TestLibraryAutoSelection(t *testing.T) {
	t.Run("Auto-select first available ebook library", func(t *testing.T) {
		libraryID := uuid.New()
		payload := map[string]interface{}{
			"title":     "Test Ebook",
			"isbn":      "9780123456789",
			"file_path": "/path/to/file.epub",
			"file_size": 1024,
			"mime_type": "application/epub+zip",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		req.Header.Set("X-User-Id", uuid.New().String())
		req.Header.Set("X-Library-Id", libraryID.String())
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Simulate auto-selection of first ebook library
			w.WriteHeader(http.StatusCreated)
			response := map[string]interface{}{
				"id":         uuid.New().String(),
				"title":      "Test Ebook",
				"isbn":       "9780123456789",
				"library_id": libraryID.String(),
			}
			json.NewEncoder(w).Encode(response)
		})

		handler.ServeHTTP(rr, req)

		assert.Equal(t, http.StatusCreated, rr.Code)

		var response map[string]interface{}
		json.Unmarshal(rr.Body.Bytes(), &response)
		assert.Equal(t, libraryID.String(), response["library_id"])
	})

	t.Run("Multiple ebook libraries - should select first", func(t *testing.T) {
		firstLibraryID := uuid.New()
		secondLibraryID := uuid.New()

		payload := map[string]interface{}{
			"title":     "Test Ebook",
			"isbn":      "9780123456789",
			"file_path": "/path/to/file.epub",
			"file_size": 1024,
			"mime_type": "application/epub+zip",
		}
		jsonData, _ := json.Marshal(payload)

		req := httptest.NewRequest("POST", "/api/ebooks", bytes.NewBuffer(jsonData))
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer admin-token")
		req.Header.Set("X-User-Role", "admin")
		req.Header.Set("X-User-Id", uuid.New().String())
		rr := httptest.NewRecorder()

		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Simulate auto-selection of first ebook library
			w.WriteHeader(http.StatusCreated)
			response := map[string]interface{}{
				"id":         uuid.New().String(),
				"title":      "Test Ebook",
				"isbn":       "9780123456789",
				"library_id": firstLibraryID.String(),
			}
			json.NewEncoder(w).Encode(response)
		})

		handler.ServeHTTP(rr, req)

		assert.Equal(t, http.StatusCreated, rr.Code)

		var response map[string]interface{}
		json.Unmarshal(rr.Body.Bytes(), &response)
		// Should select first library, not second
		assert.Equal(t, firstLibraryID.String(), response["library_id"])
		assert.NotEqual(t, secondLibraryID.String(), response["library_id"])
	})
}