package handler

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"

	"github.com/go-chi/chi/v5"

	"github.com/daniil/homelab-api/internal/middleware"
	"github.com/daniil/homelab-api/internal/model"
	"github.com/daniil/homelab-api/internal/repository"
	"github.com/daniil/homelab-api/internal/service"
)

type TaskHandler struct {
	taskService *service.TaskService
}

func NewTaskHandler(taskService *service.TaskService) *TaskHandler {
	return &TaskHandler{taskService: taskService}
}

func (h *TaskHandler) List(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	
	var completed *bool
	if c := r.URL.Query().Get("completed"); c != "" {
		b := c == "true"
		completed = &b
	}

	tasks, err := h.taskService.List(userID, completed)
	if err != nil {
		writeError(w, "failed to fetch tasks", http.StatusInternalServerError)
		return
	}

	writeJSON(w, tasks, http.StatusOK)
}

func (h *TaskHandler) Today(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())

	tasks, err := h.taskService.GetTodayTasks(userID)
	if err != nil {
		writeError(w, "failed to fetch today tasks", http.StatusInternalServerError)
		return
	}

	writeJSON(w, tasks, http.StatusOK)
}

func (h *TaskHandler) Create(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())

	var req model.CreateTaskRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, "invalid request body", http.StatusBadRequest)
		return
	}

	if req.Title == "" {
		writeError(w, "title is required", http.StatusBadRequest)
		return
	}

	task, err := h.taskService.Create(userID, &req)
	if err != nil {
		writeError(w, "failed to create task", http.StatusInternalServerError)
		return
	}

	writeJSON(w, task, http.StatusCreated)
}

func (h *TaskHandler) Get(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	taskID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		writeError(w, "invalid task id", http.StatusBadRequest)
		return
	}

	task, err := h.taskService.Get(taskID, userID)
	if err != nil {
		if errors.Is(err, repository.ErrTaskNotFound) {
			writeError(w, "task not found", http.StatusNotFound)
			return
		}
		writeError(w, "failed to fetch task", http.StatusInternalServerError)
		return
	}

	writeJSON(w, task, http.StatusOK)
}

func (h *TaskHandler) Update(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	taskID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		writeError(w, "invalid task id", http.StatusBadRequest)
		return
	}

	var req model.UpdateTaskRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, "invalid request body", http.StatusBadRequest)
		return
	}

	task, err := h.taskService.Update(taskID, userID, &req)
	if err != nil {
		if errors.Is(err, repository.ErrTaskNotFound) {
			writeError(w, "task not found", http.StatusNotFound)
			return
		}
		writeError(w, "failed to update task", http.StatusInternalServerError)
		return
	}

	writeJSON(w, task, http.StatusOK)
}

func (h *TaskHandler) Delete(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	taskID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		writeError(w, "invalid task id", http.StatusBadRequest)
		return
	}

	if err := h.taskService.Delete(taskID, userID); err != nil {
		if errors.Is(err, repository.ErrTaskNotFound) {
			writeError(w, "task not found", http.StatusNotFound)
			return
		}
		writeError(w, "failed to delete task", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}

func (h *TaskHandler) Complete(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	taskID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		writeError(w, "invalid task id", http.StatusBadRequest)
		return
	}

	task, err := h.taskService.Complete(taskID, userID)
	if err != nil {
		if errors.Is(err, repository.ErrTaskNotFound) {
			writeError(w, "task not found", http.StatusNotFound)
			return
		}
		writeError(w, "failed to complete task", http.StatusInternalServerError)
		return
	}

	writeJSON(w, task, http.StatusOK)
}

func (h *TaskHandler) Uncomplete(w http.ResponseWriter, r *http.Request) {
	userID := middleware.GetUserID(r.Context())
	taskID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		writeError(w, "invalid task id", http.StatusBadRequest)
		return
	}

	task, err := h.taskService.Uncomplete(taskID, userID)
	if err != nil {
		if errors.Is(err, repository.ErrTaskNotFound) {
			writeError(w, "task not found", http.StatusNotFound)
			return
		}
		writeError(w, "failed to uncomplete task", http.StatusInternalServerError)
		return
	}

	writeJSON(w, task, http.StatusOK)
}