"use client";

import React, { useState, useEffect } from "react";
import { Plus, Check, X, Clock, AlertCircle, GripVertical, ChevronDown, Calendar as CalendarIcon } from "lucide-react";
import { DashboardElement } from "@/components/admin/dashboard/types";
import { useDashboard } from "@/contexts/DashboardContext";

interface TodoItem {
  id: string;
  title: string;
  description?: string;
  priority: "urgent" | "high" | "normal" | "low";
  status: "pending" | "in_progress" | "completed";
  assignedTo?: string;
  dueDate?: string;
  createdAt: string;
  updatedAt: string;
  completedAt?: string;
  isUrgent: boolean;
  order: number;
}

interface TodoStats {
  total: number;
  pending: number;
  inProgress: number;
  completed: number;
  urgent: number;
  overdue: number;
}

interface TodoWidgetProps {
  element?: DashboardElement;
}

export default function TodoWidget({ element }: TodoWidgetProps) {
  // Context에서 선택된 날짜 가져오기
  const { selectedDate } = useDashboard();
  
  const [todos, setTodos] = useState<TodoItem[]>([]);
  const [stats, setStats] = useState<TodoStats | null>(null);
  const [loading, setLoading] = useState(true);
  const [filter, setFilter] = useState<"all" | "pending" | "in_progress" | "completed">("all");
  const [showAddForm, setShowAddForm] = useState(false);
  const [newTodo, setNewTodo] = useState({
    title: "",
    description: "",
    priority: "normal" as TodoItem["priority"],
    isUrgent: false,
    dueDate: "",
    assignedTo: "",
  });

  useEffect(() => {
    fetchTodos();
    const interval = setInterval(fetchTodos, 30000); // 30초마다 갱신
    return () => clearInterval(interval);
  }, [filter, selectedDate]); // selectedDate도 의존성에 추가

  const fetchTodos = async () => {
    try {
      const token = localStorage.getItem("authToken");
      const userLang = localStorage.getItem("userLang") || "KR";
      
      // 외부 DB 조회 (dataSource가 설정된 경우)
      if (element?.dataSource?.query) {
        // console.log("🔍 TodoWidget - 외부 DB 조회 시작");
        // console.log("📝 Query:", element.dataSource.query);
        // console.log("🔗 ConnectionId:", element.dataSource.externalConnectionId);
        // console.log("🔗 ConnectionType:", element.dataSource.connectionType);
        
        // 현재 DB vs 외부 DB 분기
        const apiUrl = element.dataSource.connectionType === "external" && element.dataSource.externalConnectionId
          ? `http://localhost:9771/api/external-db/query?userLang=${userLang}`
          : `http://localhost:9771/api/dashboards/execute-query?userLang=${userLang}`;
        
        const requestBody = element.dataSource.connectionType === "external" && element.dataSource.externalConnectionId
          ? {
              connectionId: parseInt(element.dataSource.externalConnectionId),
              query: element.dataSource.query,
            }
          : {
              query: element.dataSource.query,
            };

        // console.log("🌐 API URL:", apiUrl);
        // console.log("📦 Request Body:", requestBody);

        const response = await fetch(apiUrl, {
          method: "POST",
          headers: {
            "Content-Type": "application/json",
            Authorization: `Bearer ${token}`,
          },
          body: JSON.stringify(requestBody),
        });

        // console.log("📡 Response status:", response.status);

        if (response.ok) {
          const result = await response.json();
          // console.log("✅ API 응답:", result);
          // console.log("📦 result.data:", result.data);
          // console.log("📦 result.data.rows:", result.data?.rows);
          
          // API 응답 형식에 따라 데이터 추출
          const rows = result.data?.rows || result.data || [];
          // console.log("📊 추출된 rows:", rows);
          
          const externalTodos = mapExternalDataToTodos(rows);
          // console.log("📋 변환된 Todos:", externalTodos);
          // console.log("📋 변환된 Todos 개수:", externalTodos.length);
          
          setTodos(externalTodos);
          setStats(calculateStatsFromTodos(externalTodos));
          
          // console.log("✅ setTodos, setStats 호출 완료!");
        } else {
          const errorText = await response.text();
          // console.error("❌ API 오류:", errorText);
        }
      } 
      // 내장 API 조회 (기본)
      else {
        const filterParam = filter !== "all" ? `?status=${filter}` : "";
        const response = await fetch(`http://localhost:9771/api/todos${filterParam}`, {
          headers: {
            Authorization: `Bearer ${token}`,
          },
        });

        if (response.ok) {
          const result = await response.json();
          setTodos(result.data || []);
          setStats(result.stats);
        }
      }
    } catch (error) {
      // console.error("To-Do 로딩 오류:", error);
    } finally {
      setLoading(false);
    }
  };

  // 외부 DB 데이터를 TodoItem 형식으로 변환
  const mapExternalDataToTodos = (data: any[]): TodoItem[] => {
    return data.map((row, index) => ({
      id: row.id || `todo-${index}`,
      title: row.title || row.task || row.name || "제목 없음",
      description: row.description || row.desc || row.content,
      priority: row.priority || "normal",
      status: row.status || "pending",
      assignedTo: row.assigned_to || row.assignedTo || row.user,
      dueDate: row.due_date || row.dueDate || row.deadline,
      createdAt: row.created_at || row.createdAt || new Date().toISOString(),
      updatedAt: row.updated_at || row.updatedAt || new Date().toISOString(),
      completedAt: row.completed_at || row.completedAt,
      isUrgent: row.is_urgent || row.isUrgent || row.urgent || false,
      order: row.display_order || row.order || index,
    }));
  };

  // Todo 배열로부터 통계 계산
  const calculateStatsFromTodos = (todoList: TodoItem[]): TodoStats => {
    return {
      total: todoList.length,
      pending: todoList.filter((t) => t.status === "pending").length,
      inProgress: todoList.filter((t) => t.status === "in_progress").length,
      completed: todoList.filter((t) => t.status === "completed").length,
      urgent: todoList.filter((t) => t.isUrgent).length,
      overdue: todoList.filter((t) => {
        if (!t.dueDate) return false;
        return new Date(t.dueDate) < new Date() && t.status !== "completed";
      }).length,
    };
  };

  // 외부 DB 조회 여부 확인
  const isExternalData = !!element?.dataSource?.query;

  const handleAddTodo = async () => {
    if (!newTodo.title.trim()) return;
    if (isExternalData) {
      alert("외부 데이터베이스 조회 모드에서는 추가할 수 없습니다.");
      return;
    }

    try {
      const token = localStorage.getItem("authToken");
      const response = await fetch("http://localhost:9771/api/todos", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          Authorization: `Bearer ${token}`,
        },
        body: JSON.stringify(newTodo),
      });

      if (response.ok) {
        setNewTodo({
          title: "",
          description: "",
          priority: "normal",
          isUrgent: false,
          dueDate: "",
          assignedTo: "",
        });
        setShowAddForm(false);
        fetchTodos();
      }
    } catch (error) {
      // console.error("To-Do 추가 오류:", error);
    }
  };

  const handleUpdateStatus = async (id: string, status: TodoItem["status"]) => {
    try {
      const token = localStorage.getItem("authToken");
      const response = await fetch(`http://localhost:9771/api/todos/${id}`, {
        method: "PUT",
        headers: {
          "Content-Type": "application/json",
          Authorization: `Bearer ${token}`,
        },
        body: JSON.stringify({ status }),
      });

      if (response.ok) {
        fetchTodos();
      }
    } catch (error) {
      // console.error("상태 업데이트 오류:", error);
    }
  };

  const handleDelete = async (id: string) => {
    if (!confirm("이 To-Do를 삭제하시겠습니까?")) return;

    try {
      const token = localStorage.getItem("authToken");
      const response = await fetch(`http://localhost:9771/api/todos/${id}`, {
        method: "DELETE",
        headers: {
          Authorization: `Bearer ${token}`,
        },
      });

      if (response.ok) {
        fetchTodos();
      }
    } catch (error) {
      // console.error("To-Do 삭제 오류:", error);
    }
  };

  const getPriorityColor = (priority: TodoItem["priority"]) => {
    switch (priority) {
      case "urgent":
        return "bg-red-100 text-red-700 border-red-300";
      case "high":
        return "bg-orange-100 text-orange-700 border-orange-300";
      case "normal":
        return "bg-blue-100 text-blue-700 border-blue-300";
      case "low":
        return "bg-gray-100 text-gray-700 border-gray-300";
    }
  };

  const getPriorityIcon = (priority: TodoItem["priority"]) => {
    switch (priority) {
      case "urgent":
        return "🔴";
      case "high":
        return "🟠";
      case "normal":
        return "🟡";
      case "low":
        return "🟢";
    }
  };

  const getTimeRemaining = (dueDate: string) => {
    const now = new Date();
    const due = new Date(dueDate);
    const diff = due.getTime() - now.getTime();
    const hours = Math.floor(diff / (1000 * 60 * 60));
    const days = Math.floor(hours / 24);

    if (diff < 0) return "⏰ 기한 초과";
    if (days > 0) return `📅 ${days}일 남음`;
    if (hours > 0) return `⏱️ ${hours}시간 남음`;
    return "⚠️ 오늘 마감";
  };

  // 선택된 날짜로 필터링
  const filteredTodos = selectedDate
    ? todos.filter((todo) => {
        if (!todo.dueDate) return false;
        const todoDate = new Date(todo.dueDate);
        return (
          todoDate.getFullYear() === selectedDate.getFullYear() &&
          todoDate.getMonth() === selectedDate.getMonth() &&
          todoDate.getDate() === selectedDate.getDate()
        );
      })
    : todos;

  const formatSelectedDate = () => {
    if (!selectedDate) return null;
    const year = selectedDate.getFullYear();
    const month = selectedDate.getMonth() + 1;
    const day = selectedDate.getDate();
    return `${year}년 ${month}월 ${day}일`;
  };

  if (loading) {
    return (
      <div className="flex h-full items-center justify-center">
        <div className="text-gray-500">로딩 중...</div>
      </div>
    );
  }

  return (
    <div className="flex h-full flex-col bg-gradient-to-br from-slate-50 to-blue-50">
      {/* 제목 - 항상 표시 */}
      <div className="border-b border-gray-200 bg-white px-4 py-2">
        <h3 className="text-lg font-bold text-gray-800">{element?.customTitle || "To-Do / 긴급 지시"}</h3>
        {selectedDate && (
          <div className="mt-1 flex items-center gap-1 text-xs text-green-600">
            <CalendarIcon className="h-3 w-3" />
            <span className="font-semibold">{formatSelectedDate()} 할일</span>
          </div>
        )}
      </div>

      {/* 헤더 (추가 버튼, 통계, 필터) - showHeader가 false일 때만 숨김 */}
      {element?.showHeader !== false && (
        <div className="border-b border-gray-200 bg-white px-4 py-3">
          <div className="mb-3 flex items-center justify-end">
            <button
              onClick={() => setShowAddForm(!showAddForm)}
              className="flex items-center gap-1 rounded-lg bg-primary px-3 py-1.5 text-sm text-white transition-colors hover:bg-primary/90"
            >
              <Plus className="h-4 w-4" />
              추가
            </button>
          </div>

          {/* 통계 */}
          {stats && (
            <div className="grid grid-cols-4 gap-2 text-xs mb-3">
              <div className="rounded bg-blue-50 px-2 py-1.5 text-center">
                <div className="font-bold text-blue-700">{stats.pending}</div>
                <div className="text-blue-600">대기</div>
              </div>
              <div className="rounded bg-amber-50 px-2 py-1.5 text-center">
                <div className="font-bold text-amber-700">{stats.inProgress}</div>
                <div className="text-amber-600">진행중</div>
              </div>
              <div className="rounded bg-red-50 px-2 py-1.5 text-center">
                <div className="font-bold text-red-700">{stats.urgent}</div>
                <div className="text-red-600">긴급</div>
              </div>
              <div className="rounded bg-rose-50 px-2 py-1.5 text-center">
                <div className="font-bold text-rose-700">{stats.overdue}</div>
                <div className="text-rose-600">지연</div>
              </div>
            </div>
          )}

          {/* 필터 */}
          <div className="flex gap-2">
            {(["all", "pending", "in_progress", "completed"] as const).map((f) => (
              <button
                key={f}
                onClick={() => setFilter(f)}
                className={`rounded px-3 py-1 text-xs font-medium transition-colors ${
                  filter === f
                    ? "bg-primary text-white"
                    : "bg-gray-100 text-gray-600 hover:bg-gray-200"
                }`}
              >
                {f === "all" ? "전체" : f === "pending" ? "대기" : f === "in_progress" ? "진행중" : "완료"}
              </button>
            ))}
          </div>
        </div>
      )}

      {/* 추가 폼 */}
      {showAddForm && (
        <div className="border-b border-gray-200 bg-white p-4">
          <div className="space-y-2">
            <input
              type="text"
              placeholder="할 일 제목*"
              value={newTodo.title}
              onChange={(e) => setNewTodo({ ...newTodo, title: e.target.value })}
              className="w-full rounded border border-gray-300 px-3 py-2 text-sm focus:border-primary focus:outline-none"
            />
            <textarea
              placeholder="상세 설명 (선택)"
              value={newTodo.description}
              onChange={(e) => setNewTodo({ ...newTodo, description: e.target.value })}
              className="w-full rounded border border-gray-300 px-3 py-2 text-sm focus:border-primary focus:outline-none"
              rows={2}
            />
            <div className="grid grid-cols-2 gap-2">
              <select
                value={newTodo.priority}
                onChange={(e) => setNewTodo({ ...newTodo, priority: e.target.value as TodoItem["priority"] })}
                className="rounded border border-gray-300 px-3 py-2 text-sm focus:border-primary focus:outline-none"
              >
                <option value="low">🟢 낮음</option>
                <option value="normal">🟡 보통</option>
                <option value="high">🟠 높음</option>
                <option value="urgent">🔴 긴급</option>
              </select>
              <input
                type="datetime-local"
                value={newTodo.dueDate}
                onChange={(e) => setNewTodo({ ...newTodo, dueDate: e.target.value })}
                className="rounded border border-gray-300 px-3 py-2 text-sm focus:border-primary focus:outline-none"
              />
            </div>
            <div className="flex items-center gap-2">
              <label className="flex items-center gap-2 text-sm">
                <input
                  type="checkbox"
                  checked={newTodo.isUrgent}
                  onChange={(e) => setNewTodo({ ...newTodo, isUrgent: e.target.checked })}
                  className="h-4 w-4 rounded border-gray-300"
                />
                <span className="text-red-600 font-medium">긴급 지시</span>
              </label>
            </div>
            <div className="flex gap-2">
              <button
                onClick={handleAddTodo}
                className="flex-1 rounded bg-primary px-4 py-2 text-sm text-white hover:bg-primary/90"
              >
                추가
              </button>
              <button
                onClick={() => setShowAddForm(false)}
                className="rounded bg-gray-200 px-4 py-2 text-sm text-gray-700 hover:bg-gray-300"
              >
                취소
              </button>
            </div>
          </div>
        </div>
      )}

      {/* To-Do 리스트 */}
      <div className="flex-1 overflow-y-auto p-4">
        {filteredTodos.length === 0 ? (
          <div className="flex h-full items-center justify-center text-gray-400">
            <div className="text-center">
              <div className="mb-2 text-4xl">📝</div>
              <div>{selectedDate ? `${formatSelectedDate()} 할 일이 없습니다` : "할 일이 없습니다"}</div>
            </div>
          </div>
        ) : (
          <div className="space-y-2">
            {filteredTodos.map((todo) => (
              <div
                key={todo.id}
                className={`group relative rounded-lg border-2 bg-white p-3 shadow-sm transition-all hover:shadow-md ${
                  todo.isUrgent ? "border-red-400" : "border-gray-200"
                } ${todo.status === "completed" ? "opacity-60" : ""}`}
              >
                <div className="flex items-start gap-3">
                  {/* 우선순위 아이콘 */}
                  <div className="mt-1 text-lg">{getPriorityIcon(todo.priority)}</div>

                  {/* 내용 */}
                  <div className="flex-1">
                    <div className="flex items-start justify-between gap-2">
                      <div className="flex-1">
                        <div className={`font-medium ${todo.status === "completed" ? "line-through" : ""}`}>
                          {todo.isUrgent && <span className="mr-1 text-red-600">⚡</span>}
                          {todo.title}
                        </div>
                        {todo.description && (
                          <div className="mt-1 text-xs text-gray-600">{todo.description}</div>
                        )}
                        {todo.dueDate && (
                          <div className="mt-1 text-xs text-gray-500">{getTimeRemaining(todo.dueDate)}</div>
                        )}
                      </div>

                      {/* 액션 버튼 */}
                      <div className="flex gap-1">
                        {todo.status !== "completed" && (
                          <button
                            onClick={() => handleUpdateStatus(todo.id, "completed")}
                            className="rounded p-1 text-green-600 hover:bg-green-50"
                            title="완료"
                          >
                            <Check className="h-4 w-4" />
                          </button>
                        )}
                        <button
                          onClick={() => handleDelete(todo.id)}
                          className="rounded p-1 text-red-600 hover:bg-red-50"
                          title="삭제"
                        >
                          <X className="h-4 w-4" />
                        </button>
                      </div>
                    </div>

                    {/* 상태 변경 */}
                    {todo.status !== "completed" && (
                      <div className="mt-2 flex gap-1">
                        <button
                          onClick={() => handleUpdateStatus(todo.id, "pending")}
                          className={`rounded px-2 py-1 text-xs ${
                            todo.status === "pending"
                              ? "bg-blue-100 text-blue-700"
                              : "bg-gray-100 text-gray-600 hover:bg-gray-200"
                          }`}
                        >
                          대기
                        </button>
                        <button
                          onClick={() => handleUpdateStatus(todo.id, "in_progress")}
                          className={`rounded px-2 py-1 text-xs ${
                            todo.status === "in_progress"
                              ? "bg-amber-100 text-amber-700"
                              : "bg-gray-100 text-gray-600 hover:bg-gray-200"
                          }`}
                        >
                          진행중
                        </button>
                      </div>
                    )}
                  </div>
                </div>
              </div>
            ))}
          </div>
        )}
      </div>
    </div>
  );
}