package handlers

import (
	"encoding/json"
	"net/http"
	"prak-03-todo/internal/db"
	"strconv"

	"github.com/gorilla/mux"
)

// CreateGroupHandler handles POST /groups
func CreateGroupHandler(w http.ResponseWriter, r *http.Request) {
	var groupRequest struct {
		GroupName string `json:"group_name"`
	}

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

	// Validate input
	if groupRequest.GroupName == "" {
		http.Error(w, "Group name is required", http.StatusBadRequest)
		return
	}

	// Create group using query function
	group, err := db.CreateGroup(groupRequest.GroupName)
	if err != nil {
		http.Error(w, "Failed to create group", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(group)
}

// RemoveGroupHandler handles DELETE /groups/{groupId}
func RemoveGroupHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	groupID, err := strconv.Atoi(vars["groupId"])
	if err != nil {
		http.Error(w, "Invalid group ID", http.StatusBadRequest)
		return
	}

	// Delete group using query function
	err = db.DeleteGroup(groupID)
	if err != nil {
		if err.Error() == "group not found" {
			http.Error(w, "Group not found", http.StatusNotFound)
			return
		}
		http.Error(w, "Failed to delete group", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	w.Write([]byte("Group ID " + vars["groupId"] + " Removed"))
}

// GetGroupHandler handles GET /groups/{groupId}
func GetGroupHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	groupID, err := strconv.Atoi(vars["groupId"])
	if err != nil {
		http.Error(w, "Invalid group ID", http.StatusBadRequest)
		return
	}

	// Get group using query function
	group, err := db.GetGroupByID(groupID)
	if err != nil {
		if err.Error() == "group not found" {
			http.Error(w, "Group not found", http.StatusNotFound)
			return
		}
		http.Error(w, "Failed to fetch group", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(group)
}

// GetAllGroupsHandler handles GET /groups
func GetAllGroupsHandler(w http.ResponseWriter, r *http.Request) {
	groups, err := db.GetAllGroups()
	if err != nil {
		http.Error(w, "Failed to fetch groups", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(groups)
}

// Home handles GET /
func Home(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("Hello from Task Management API"))
}