package nativeapi

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"

	"github.com/navidrome/navidrome/conf/configtest"
	"github.com/navidrome/navidrome/consts"
	"github.com/navidrome/navidrome/core"
	"github.com/navidrome/navidrome/core/auth"
	"github.com/navidrome/navidrome/model"
	"github.com/navidrome/navidrome/server"
	"github.com/navidrome/navidrome/tests"
	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("Library API", func() {
	var ds model.DataStore
	var router http.Handler
	var adminUser, regularUser model.User
	var library1, library2 model.Library

	BeforeEach(func() {
		DeferCleanup(configtest.SetupConfig())
		ds = &tests.MockDataStore{}
		auth.Init(ds)
		nativeRouter := New(ds, nil, nil, nil, core.NewMockLibraryService())
		router = server.JWTVerifier(nativeRouter)

		// Create test users
		adminUser = model.User{
			ID:          "admin-1",
			UserName:    "admin",
			Name:        "Admin User",
			IsAdmin:     true,
			NewPassword: "adminpass",
		}
		regularUser = model.User{
			ID:          "user-1",
			UserName:    "regular",
			Name:        "Regular User",
			IsAdmin:     false,
			NewPassword: "userpass",
		}

		// Create test libraries
		library1 = model.Library{
			ID:   1,
			Name: "Test Library 1",
			Path: "/music/library1",
		}
		library2 = model.Library{
			ID:   2,
			Name: "Test Library 2",
			Path: "/music/library2",
		}

		// Store in mock datastore
		Expect(ds.User(context.TODO()).Put(&adminUser)).To(Succeed())
		Expect(ds.User(context.TODO()).Put(&regularUser)).To(Succeed())
		Expect(ds.Library(context.TODO()).Put(&library1)).To(Succeed())
		Expect(ds.Library(context.TODO()).Put(&library2)).To(Succeed())
	})

	Describe("Library CRUD Operations", func() {
		Context("as admin user", func() {
			var adminToken string

			BeforeEach(func() {
				var err error
				adminToken, err = auth.CreateToken(&adminUser)
				Expect(err).ToNot(HaveOccurred())
			})

			Describe("GET /api/library", func() {
				It("returns all libraries", func() {
					req := createAuthenticatedRequest("GET", "/library", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))

					var libraries []model.Library
					err := json.Unmarshal(w.Body.Bytes(), &libraries)
					Expect(err).ToNot(HaveOccurred())
					Expect(libraries).To(HaveLen(2))
					Expect(libraries[0].Name).To(Equal("Test Library 1"))
					Expect(libraries[1].Name).To(Equal("Test Library 2"))
				})
			})

			Describe("GET /api/library/{id}", func() {
				It("returns a specific library", func() {
					req := createAuthenticatedRequest("GET", "/library/1", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))

					var library model.Library
					err := json.Unmarshal(w.Body.Bytes(), &library)
					Expect(err).ToNot(HaveOccurred())
					Expect(library.Name).To(Equal("Test Library 1"))
					Expect(library.Path).To(Equal("/music/library1"))
				})

				It("returns 404 for non-existent library", func() {
					req := createAuthenticatedRequest("GET", "/library/999", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusNotFound))
				})

				It("returns 400 for invalid library ID", func() {
					req := createAuthenticatedRequest("GET", "/library/invalid", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusNotFound))
				})
			})

			Describe("POST /api/library", func() {
				It("creates a new library", func() {
					newLibrary := model.Library{
						Name: "New Library",
						Path: "/music/new",
					}
					body, _ := json.Marshal(newLibrary)
					req := createAuthenticatedRequest("POST", "/library", bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))
				})

				It("validates required fields", func() {
					invalidLibrary := model.Library{
						Name: "", // Missing name
						Path: "/music/invalid",
					}
					body, _ := json.Marshal(invalidLibrary)
					req := createAuthenticatedRequest("POST", "/library", bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
					Expect(w.Body.String()).To(ContainSubstring("library name is required"))
				})

				It("validates path field", func() {
					invalidLibrary := model.Library{
						Name: "Valid Name",
						Path: "", // Missing path
					}
					body, _ := json.Marshal(invalidLibrary)
					req := createAuthenticatedRequest("POST", "/library", bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
					Expect(w.Body.String()).To(ContainSubstring("library path is required"))
				})
			})

			Describe("PUT /api/library/{id}", func() {
				It("updates an existing library", func() {
					updatedLibrary := model.Library{
						Name: "Updated Library 1",
						Path: "/music/updated",
					}
					body, _ := json.Marshal(updatedLibrary)
					req := createAuthenticatedRequest("PUT", "/library/1", bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))

					var updated model.Library
					err := json.Unmarshal(w.Body.Bytes(), &updated)
					Expect(err).ToNot(HaveOccurred())
					Expect(updated.ID).To(Equal(1))
					Expect(updated.Name).To(Equal("Updated Library 1"))
					Expect(updated.Path).To(Equal("/music/updated"))
				})

				It("validates required fields on update", func() {
					invalidLibrary := model.Library{
						Name: "",
						Path: "/music/path",
					}
					body, _ := json.Marshal(invalidLibrary)
					req := createAuthenticatedRequest("PUT", "/library/1", bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
				})
			})

			Describe("DELETE /api/library/{id}", func() {
				It("deletes an existing library", func() {
					req := createAuthenticatedRequest("DELETE", "/library/1", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))
				})

				It("returns 404 for non-existent library", func() {
					req := createAuthenticatedRequest("DELETE", "/library/999", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusNotFound))
				})
			})
		})

		Context("as regular user", func() {
			var userToken string

			BeforeEach(func() {
				var err error
				userToken, err = auth.CreateToken(&regularUser)
				Expect(err).ToNot(HaveOccurred())
			})

			It("denies access to library management endpoints", func() {
				endpoints := []string{
					"GET /library",
					"POST /library",
					"GET /library/1",
					"PUT /library/1",
					"DELETE /library/1",
				}

				for _, endpoint := range endpoints {
					parts := strings.Split(endpoint, " ")
					method, path := parts[0], parts[1]

					req := createAuthenticatedRequest(method, path, nil, userToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusForbidden))
				}
			})
		})

		Context("without authentication", func() {
			It("denies access to library management endpoints", func() {
				req := createUnauthenticatedRequest("GET", "/library", nil)
				w := httptest.NewRecorder()

				router.ServeHTTP(w, req)

				Expect(w.Code).To(Equal(http.StatusUnauthorized))
			})
		})
	})

	Describe("User-Library Association Operations", func() {
		Context("as admin user", func() {
			var adminToken string

			BeforeEach(func() {
				var err error
				adminToken, err = auth.CreateToken(&adminUser)
				Expect(err).ToNot(HaveOccurred())
			})

			Describe("GET /api/user/{id}/library", func() {
				It("returns user's libraries", func() {
					// Set up user libraries
					err := ds.User(context.TODO()).SetUserLibraries(regularUser.ID, []int{1, 2})
					Expect(err).ToNot(HaveOccurred())

					req := createAuthenticatedRequest("GET", fmt.Sprintf("/user/%s/library", regularUser.ID), nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))

					var libraries []model.Library
					err = json.Unmarshal(w.Body.Bytes(), &libraries)
					Expect(err).ToNot(HaveOccurred())
					Expect(libraries).To(HaveLen(2))
				})

				It("returns 404 for non-existent user", func() {
					req := createAuthenticatedRequest("GET", "/user/non-existent/library", nil, adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusNotFound))
				})
			})

			Describe("PUT /api/user/{id}/library", func() {
				It("sets user's libraries", func() {
					request := map[string][]int{
						"libraryIds": {1, 2},
					}
					body, _ := json.Marshal(request)
					req := createAuthenticatedRequest("PUT", fmt.Sprintf("/user/%s/library", regularUser.ID), bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusOK))

					var libraries []model.Library
					err := json.Unmarshal(w.Body.Bytes(), &libraries)
					Expect(err).ToNot(HaveOccurred())
					Expect(libraries).To(HaveLen(2))
				})

				It("validates library IDs exist", func() {
					request := map[string][]int{
						"libraryIds": {999}, // Non-existent library
					}
					body, _ := json.Marshal(request)
					req := createAuthenticatedRequest("PUT", fmt.Sprintf("/user/%s/library", regularUser.ID), bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
					Expect(w.Body.String()).To(ContainSubstring("library ID 999 does not exist"))
				})

				It("requires at least one library for regular users", func() {
					request := map[string][]int{
						"libraryIds": {}, // Empty libraries
					}
					body, _ := json.Marshal(request)
					req := createAuthenticatedRequest("PUT", fmt.Sprintf("/user/%s/library", regularUser.ID), bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
					Expect(w.Body.String()).To(ContainSubstring("at least one library must be assigned"))
				})

				It("prevents manual assignment to admin users", func() {
					request := map[string][]int{
						"libraryIds": {1},
					}
					body, _ := json.Marshal(request)
					req := createAuthenticatedRequest("PUT", fmt.Sprintf("/user/%s/library", adminUser.ID), bytes.NewBuffer(body), adminToken)
					w := httptest.NewRecorder()

					router.ServeHTTP(w, req)

					Expect(w.Code).To(Equal(http.StatusBadRequest))
					Expect(w.Body.String()).To(ContainSubstring("cannot manually assign libraries to admin users"))
				})
			})
		})

		Context("as regular user", func() {
			var userToken string

			BeforeEach(func() {
				var err error
				userToken, err = auth.CreateToken(&regularUser)
				Expect(err).ToNot(HaveOccurred())
			})

			It("denies access to user-library association endpoints", func() {
				req := createAuthenticatedRequest("GET", fmt.Sprintf("/user/%s/library", regularUser.ID), nil, userToken)
				w := httptest.NewRecorder()

				router.ServeHTTP(w, req)

				Expect(w.Code).To(Equal(http.StatusForbidden))
			})
		})
	})
})

// Helper functions

func createAuthenticatedRequest(method, path string, body *bytes.Buffer, token string) *http.Request {
	if body == nil {
		body = &bytes.Buffer{}
	}
	req := httptest.NewRequest(method, path, body)
	req.Header.Set(consts.UIAuthorizationHeader, "Bearer "+token)
	req.Header.Set("Content-Type", "application/json")
	return req
}

func createUnauthenticatedRequest(method, path string, body *bytes.Buffer) *http.Request {
	if body == nil {
		body = &bytes.Buffer{}
	}
	req := httptest.NewRequest(method, path, body)
	req.Header.Set("Content-Type", "application/json")
	return req
}