"use client";

import { useEffect, useState } from "react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { RefreshCw } from "lucide-react";

interface Task {
  id: number;
  headline: string;
  description: string;
  date: string;
  dateToFinish: string;
  projectId: number;
  projectName: string;
  type: string;
  status: number;
  assignedTo: number[];
  editorId: string;
  editorFirstname: string | null;
  editorLastname: string | null;
  authorFirstname: string;
  authorLastname: string;
  milestoneHeadline: string | null;
  tags: string;
}

interface ProjectSummary {
  name: string;
  tasks: {
    status: number;
    count: number;
  }[];
}

export function Flow() {
  const [tasks, setTasks] = useState<Task[]>([]);
  const [error, setError] = useState<string | null>(null);
  const [loading, setLoading] = useState(true);
  const [refreshing, setRefreshing] = useState(false);

  const getStatusLabel = (status: number): string => {
    switch (status) {
      case 1: return 'New';
      case 2: return 'Ready';
      case 3: return 'In Progress';
      case 4: return 'Review';
      case 5: return 'Done';
      default: return 'Unknown';
    }
  };

  const getStatusColor = (status: number): string => {
    switch (status) {
      case 1: return 'bg-blue-500';
      case 2: return 'bg-green-500';
      case 3: return 'bg-yellow-500';
      case 4: return 'bg-purple-500';
      case 5: return 'bg-gray-500';
      default: return 'bg-gray-300';
    }
  };

  const getDateToSort = (task: Task): number => {
    // Try to use dateToFinish first, then fall back to date
    const dateStr = task.dateToFinish !== '0000-00-00 00:00:00' 
      ? task.dateToFinish 
      : task.date;
    return new Date(dateStr).getTime();
  };

  const formatDate = (dateStr: string): string => {
    if (!dateStr || dateStr === '0000-00-00 00:00:00') return '';
    try {
      const date = new Date(dateStr);
      if (isNaN(date.getTime())) return '';
      return date.toLocaleDateString('fr-FR', {
        day: '2-digit',
        month: '2-digit',
        year: 'numeric'
      });
    } catch {
      return '';
    }
  };

  const fetchTasks = async (isRefresh = false) => {
    try {
      if (isRefresh) setRefreshing(true);
      
      const response = await fetch('/api/leantime/tasks');
      if (!response.ok) throw new Error('Failed to fetch tasks');

      const data = await response.json();
      if (!data.tasks || !Array.isArray(data.tasks)) {
        console.warn('No tasks found in response:', data);
        setTasks([]);
        return;
      }

      // Sort tasks by date (oldest first)
      const sortedTasks = data.tasks
        .filter((task: Task) => 
          task.headline && 
          typeof task.headline === 'string' &&
          task.status !== 5 && // Not done
          Array.isArray(task.assignedTo) && task.assignedTo.length > 0 // Has assignments
        )
        .sort((a: Task, b: Task) => {
          // First sort by status (new tasks first)
          if (a.status !== b.status) {
            return a.status - b.status;
          }
          // Then sort by due date
          return getDateToSort(a) - getDateToSort(b);
        });

      // Limit to 6 tasks
      setTasks(sortedTasks.slice(0, 6));
      setError(null);
    } catch (err) {
      console.error('Error fetching tasks:', err);
      setError('Failed to fetch tasks');
    } finally {
      setLoading(false);
      setRefreshing(false);
    }
  };

  useEffect(() => {
    fetchTasks();
  }, []);

  return (
    <Card className="transition-transform duration-500 ease-in-out transform hover:scale-105">
      <CardHeader className="flex flex-row items-center justify-between pb-2">
        <CardTitle className="text-lg font-medium">My ToDos</CardTitle>
        <Button
          variant="ghost"
          size="icon"
          onClick={() => fetchTasks(true)}
          disabled={refreshing}
          className={refreshing ? 'animate-spin' : ''}
        >
          <RefreshCw className="h-4 w-4" />
        </Button>
      </CardHeader>
      <CardContent>
        {loading ? (
          <div className="flex items-center justify-center py-4">
            <div className="h-4 w-4 animate-spin rounded-full border-2 border-primary border-t-transparent" />
          </div>
        ) : error ? (
          <div className="text-center text-sm text-red-500">{error}</div>
        ) : tasks.length === 0 ? (
          <div className="text-center text-sm text-gray-500">No tasks assigned to you</div>
        ) : (
          <div className="space-y-2">
            {tasks.map((task) => (
              <div 
                key={task.id} 
                className="p-3 rounded-lg bg-white/50 backdrop-blur-sm hover:bg-white/60 transition-colors border border-gray-200"
              >
                <div className="flex items-start gap-3">
                  <div className="flex-1">
                    <div className="flex items-center gap-2">
                      <h3 className="text-sm font-medium text-blue-600 hover:text-blue-800 truncate" title={task.headline}>
                        {task.headline}
                      </h3>
                      <span className={`px-2 py-0.5 text-xs rounded-full ${getStatusColor(task.status)} text-white`}>
                        {getStatusLabel(task.status)}
                      </span>
                    </div>
                    <div className="mt-1 flex items-center gap-2 text-xs text-gray-500">
                      {task.projectName && (
                        <span className="inline-flex items-center">
                          <span className="mr-1">📁</span> {task.projectName}
                        </span>
                      )}
                      {task.dateToFinish && task.dateToFinish !== '0000-00-00 00:00:00' && (
                        <span className="inline-flex items-center">
                          <span className="mr-1">📅</span> {formatDate(task.dateToFinish)}
                        </span>
                      )}
                    </div>
                  </div>
                </div>
              </div>
            ))}
          </div>
        )}
      </CardContent>
    </Card>
  );
}