package app

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"
	"task_manager/internal/domain/tasks"
	"task_manager/internal/domain/users"
	"task_manager/internal/persistance"

	gorilla "github.com/gorilla/mux"
)

const (
	api_version string = "/api/v1"
)

type ErrorResponse struct {
	Code    int    `json:"code"`    // Http code
	Message string `json:"message"` // Обычный текст ошибки
	Error   string `json:"error"`   // Машинный текст ошибки
}

func (rm *TaskManager) RegisterRoutes(router *gorilla.Router) {

	router.HandleFunc(api_version+"/user/login", rm.handleLogin).Methods(http.MethodPost)
	router.HandleFunc(api_version+"/user/register", rm.handleRegistrateUser).Methods(http.MethodPost)
	router.HandleFunc(api_version+"/user/tasks", rm.handleUserTasks).Methods(http.MethodGet)
	router.HandleFunc(api_version+"/user/projects", rm.handleUserProjects).Methods(http.MethodGet)
	router.HandleFunc(api_version+"/user/projects", rm.handleAssignUserToProject).Methods(http.MethodPost)

	router.HandleFunc(api_version+"/projects", rm.handleCreateProject).Methods(http.MethodPost)
	router.HandleFunc(api_version+"/projects", rm.handleGetProjects).Methods(http.MethodGet)

	router.HandleFunc(api_version+"/projects/tasks", rm.handleCreateTask).Methods(http.MethodPost)
	router.HandleFunc(api_version+"/projects/tasks/{task_id}", rm.handleUpdateTask).Methods(http.MethodPatch)

	router.HandleFunc(api_version+"/projects/sprints", rm.handleCreateSprint).Methods(http.MethodPost)
	router.HandleFunc(api_version+"/projects/users", rm.handleGetProjectUsers).Methods(http.MethodGet)

}

func (rm *TaskManager) handleLogin(w http.ResponseWriter, r *http.Request) {
	var input struct {
		Name     string `json:"name"`
		Password string `json:"password"`
	}

	err := json.NewDecoder(r.Body).Decode(&input)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid request payload", err)
		return
	}

	user, err := rm.repo.GetUser(input.Name)
	if err != nil || user.Password != persistance.GetMD5Hash(input.Password) {
		respondWithError(w, http.StatusUnauthorized, "Invalid username or password", errors.New("authentication failed"))
		return
	}

	respondWithJSON(w, http.StatusOK, user)
}
func (rm *TaskManager) handleRegistrateUser(w http.ResponseWriter, r *http.Request) {
	var user users.User
	err := json.NewDecoder(r.Body).Decode(&user)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid request payload", err)
		return
	}

	err = rm.repo.AddUser(&user)
	if err != nil {
		respondWithError(w, http.StatusInternalServerError, "Failed to create user", err)
		return
	}

	respondWithJSON(w, http.StatusCreated, user)
}
func (rm *TaskManager) handleUserTasks(w http.ResponseWriter, r *http.Request) {
	userID := r.URL.Query().Get("id_user")
	if userID == "" {
		respondWithError(w, http.StatusBadRequest, "Missing user ID", errors.New("id_user parameter required"))
		return
	}

	id, err := strconv.Atoi(userID)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid user ID", err)
		return
	}

	tasks, err := rm.repo.GetUserTasks(id)
	if err != nil {
		respondWithError(w, http.StatusInternalServerError, "Failed to fetch user tasks", err)
		return
	}

	respondWithJSON(w, http.StatusOK, tasks)
}
func (rm *TaskManager) handleUserProjects(w http.ResponseWriter, r *http.Request) {
	userID := r.URL.Query().Get("id_user")
	if userID == "" {
		respondWithError(w, http.StatusBadRequest, "Missing user ID", errors.New("id_user parameter required"))
		return
	}

	_, err := strconv.Atoi(userID)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid user ID", err)
		return
	}

	// Заглушка: здесь предполагается метод получения проектов пользователя
	// Для реализации необходимо будет добавить соответствующий метод в репозиторий
	projects := []string{"Project 1", "Project 2"} // Пример данных

	respondWithJSON(w, http.StatusOK, projects)
}
func (rm *TaskManager) handleAssignUserToProject(w http.ResponseWriter, r *http.Request) {
	var input struct {
		IdUser    int `json:"id_user"`
		IdProject int `json:"id_project"`
	}

	err := json.NewDecoder(r.Body).Decode(&input)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid request payload", err)
		return
	}

	// Заглушка: реализация привязки пользователя к проекту
	// Для добавления необходимо доработать метод в репозитории

	respondWithJSON(w, http.StatusOK, map[string]string{
		"message": "User assigned to project successfully",
	})
}

func (rm *TaskManager) handleCreateProject(w http.ResponseWriter, r *http.Request) {
	respondWithJSON(w, http.StatusNotImplemented, map[string]string{
		"message": "Create project not implemented yet",
	})
}
func (rm *TaskManager) handleCreateTask(w http.ResponseWriter, r *http.Request) {
	var task tasks.Task
	err := json.NewDecoder(r.Body).Decode(&task)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid request payload", err)
		return
	}

	err = rm.repo.AddTask(&task)
	if err != nil {
		respondWithError(w, http.StatusInternalServerError, "Failed to create task", err)
		return
	}

	respondWithJSON(w, http.StatusCreated, task)
}
func (rm *TaskManager) handleCreateSprint(w http.ResponseWriter, r *http.Request) {
	taskID := gorilla.Vars(r)["task_id"]
	id, err := strconv.Atoi(taskID)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid task ID", err)
		return
	}

	var task tasks.Task
	err = json.NewDecoder(r.Body).Decode(&task)
	if err != nil {
		respondWithError(w, http.StatusBadRequest, "Invalid request payload", err)
		return
	}

	task.Id = id
	err = rm.repo.UpdateTask(task)
	if err != nil {
		respondWithError(w, http.StatusInternalServerError, "Failed to update task", err)
		return
	}

	respondWithJSON(w, http.StatusOK, task)
}
func (rm *TaskManager) handleGetProjectUsers(w http.ResponseWriter, r *http.Request) {
	respondWithJSON(w, http.StatusNotImplemented, map[string]string{
		"message": "Get projects not implemented yet",
	})
}

func (rm *TaskManager) handleUpdateTask(w http.ResponseWriter, r *http.Request) {
	respondWithJSON(w, http.StatusNotImplemented, map[string]string{
		"message": "Create sprint not implemented yet",
	})
}
func (rm *TaskManager) handleGetProjects(w http.ResponseWriter, r *http.Request) {
	respondWithJSON(w, http.StatusNotImplemented, map[string]string{
		"message": "Get project users not implemented yet",
	})
}

func respondWithError(w http.ResponseWriter, code int, message string, err error) {
	w.WriteHeader(code)
	json.NewEncoder(w).Encode(ErrorResponse{
		Code:    code,
		Message: message,
		Error:   err.Error(),
	})
}

func respondWithJSON(w http.ResponseWriter, code int, payload interface{}) {
	w.WriteHeader(code)
	json.NewEncoder(w).Encode(payload)
}