import { useState } from 'react';
import { useUser } from '../context/UserContext';
import { useProject } from '../context/ProjectContext';
import { api } from '../api/client';

interface LocalTask {
  id: string;
  title: string;
  description: string;
}

export function TaskSetupPage({ onComplete }: { onComplete: () => void }) {
  const { user, logout } = useUser();
  const { currentProject, clearProject } = useProject();

  const [tasks, setTasks] = useState<LocalTask[]>([]);

  // Manual form state
  const [manualTitle, setManualTitle] = useState('');
  const [manualDescription, setManualDescription] = useState('');

  // Edit state
  const [editingId, setEditingId] = useState<string | null>(null);
  const [editTitle, setEditTitle] = useState('');
  const [editDescription, setEditDescription] = useState('');

  const [isGenerating, setIsGenerating] = useState(false);
  const [isSaving, setIsSaving] = useState(false);
  const [error, setError] = useState('');
  const [saveProgress, setSaveProgress] = useState({ current: 0, total: 0 });

  const handleLogout = () => {
    clearProject();
    logout();
  };

  const generateId = () => Math.random().toString(36).substring(2, 9);

  const handleAddManualTask = () => {
    if (!manualTitle.trim()) return;

    setTasks([
      ...tasks,
      {
        id: generateId(),
        title: manualTitle.trim(),
        description: manualDescription.trim(),
      },
    ]);
    setManualTitle('');
    setManualDescription('');
  };

  const handleGenerateTasks = async () => {
    if (!currentProject) return;

    setIsGenerating(true);
    setError('');

    try {
      const result = await api.generateTasks(currentProject.id, 50);

      const newTasks = result.tasks.map((t) => ({
        id: generateId(),
        title: t.title,
        description: t.description,
      }));

      setTasks([...tasks, ...newTasks]);
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to generate tasks');
    } finally {
      setIsGenerating(false);
    }
  };

  const handleDeleteTask = (id: string) => {
    setTasks(tasks.filter((t) => t.id !== id));
  };

  const handleStartEdit = (task: LocalTask) => {
    setEditingId(task.id);
    setEditTitle(task.title);
    setEditDescription(task.description);
  };

  const handleSaveEdit = () => {
    if (!editingId) return;

    setTasks(
      tasks.map((t) =>
        t.id === editingId
          ? { ...t, title: editTitle.trim(), description: editDescription.trim() }
          : t
      )
    );
    setEditingId(null);
    setEditTitle('');
    setEditDescription('');
  };

  const handleCancelEdit = () => {
    setEditingId(null);
    setEditTitle('');
    setEditDescription('');
  };

  const handleSaveAndContinue = async () => {
    if (tasks.length === 0 || !currentProject) return;

    setIsSaving(true);
    setError('');
    setSaveProgress({ current: 0, total: tasks.length });

    try {
      for (let i = 0; i < tasks.length; i++) {
        const task = tasks[i];
        await api.createTask(currentProject.id, {
          title: task.title,
          description: task.description,
        });
        setSaveProgress({ current: i + 1, total: tasks.length });
      }

      onComplete();
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to save tasks');
    } finally {
      setIsSaving(false);
    }
  };

  const handleClearAll = () => {
    setTasks([]);
  };

  if (!user || !currentProject) return null;

  return (
    <div className="min-h-screen bg-gradient-to-br from-slate-900 via-purple-900 to-slate-900">
      {/* Header */}
      <header className="bg-white/5 backdrop-blur-lg border-b border-white/10">
        <div className="max-w-6xl mx-auto px-4 py-4 flex items-center justify-between">
          <div className="flex items-center gap-3">
            <h1 className="text-xl font-bold text-white">Project Memory</h1>
            <span className="text-purple-300/50">|</span>
            <span className="text-purple-300">{currentProject.name}</span>
          </div>
          <div className="flex items-center gap-4">
            <span className="text-purple-300 text-sm">
              {user.firstName} ({user.id})
            </span>
            <button
              onClick={handleLogout}
              className="px-3 py-1.5 bg-white/10 hover:bg-white/20 text-white rounded-lg transition-all text-sm"
            >
              Logout
            </button>
          </div>
        </div>
      </header>

      {/* Main Content */}
      <main className="max-w-6xl mx-auto px-4 py-6">
        {/* Page Title */}
        <div className="mb-6">
          <h2 className="text-2xl font-bold text-white mb-1">Set Up Tasks</h2>
          <p className="text-purple-300 text-sm">
            Add tasks manually or generate demo tasks with AI (max 50)
          </p>
        </div>

        {/* Error Display */}
        {error && (
          <div className="mb-4 p-3 bg-red-500/20 border border-red-500/50 rounded-lg text-red-200 text-sm">
            {error}
          </div>
        )}

        {/* Two Column Layout */}
        <div className="grid lg:grid-cols-3 gap-6">
          {/* Left Column - Add Tasks */}
          <div className="lg:col-span-1 space-y-4">
            {/* Manual Add */}
            <div className="bg-white/10 backdrop-blur-lg rounded-xl p-4 border border-white/20">
              <h3 className="text-white font-medium mb-3">Add Task</h3>
              <div className="space-y-3">
                <input
                  type="text"
                  value={manualTitle}
                  onChange={(e) => setManualTitle(e.target.value)}
                  placeholder="Task title"
                  className="w-full px-3 py-2 bg-white/5 border border-white/10 rounded-lg text-white placeholder-white/40 focus:outline-none focus:ring-2 focus:ring-purple-500 text-sm"
                  onKeyDown={(e) => e.key === 'Enter' && handleAddManualTask()}
                />
                <textarea
                  value={manualDescription}
                  onChange={(e) => setManualDescription(e.target.value)}
                  placeholder="Description (optional)"
                  rows={2}
                  className="w-full px-3 py-2 bg-white/5 border border-white/10 rounded-lg text-white placeholder-white/40 focus:outline-none focus:ring-2 focus:ring-purple-500 resize-none text-sm"
                />
                <button
                  onClick={handleAddManualTask}
                  disabled={!manualTitle.trim()}
                  className="w-full px-3 py-2 bg-purple-600 hover:bg-purple-700 disabled:bg-purple-800 disabled:cursor-not-allowed text-white rounded-lg transition-all text-sm"
                >
                  + Add Task
                </button>
              </div>
            </div>

            {/* AI Generate */}
            <div className="bg-purple-600/20 backdrop-blur-lg rounded-xl p-4 border border-purple-500/30">
              <h3 className="text-white font-medium mb-2">AI Generate</h3>
              <p className="text-purple-300/70 text-xs mb-3">
                Generate 50 demo tasks based on your project
              </p>
              <button
                onClick={handleGenerateTasks}
                disabled={isGenerating}
                className="w-full px-3 py-2 bg-purple-600 hover:bg-purple-700 disabled:bg-purple-800 text-white rounded-lg transition-all text-sm flex items-center justify-center gap-2"
              >
                {isGenerating ? (
                  <>
                    <span className="animate-spin">⏳</span> Generating...
                  </>
                ) : (
                  <>✨ Generate Demo Tasks</>
                )}
              </button>
            </div>

            {/* Actions */}
            {tasks.length > 0 && (
              <div className="space-y-2">
                <button
                  onClick={handleSaveAndContinue}
                  disabled={isSaving}
                  className="w-full px-4 py-3 bg-green-600 hover:bg-green-700 disabled:bg-green-800 text-white font-medium rounded-lg transition-all flex items-center justify-center gap-2"
                >
                  {isSaving ? (
                    <>Saving... ({saveProgress.current}/{saveProgress.total})</>
                  ) : (
                    <>Save & Continue →</>
                  )}
                </button>
                <button
                  onClick={handleClearAll}
                  disabled={isSaving}
                  className="w-full px-3 py-2 bg-white/5 hover:bg-white/10 text-red-400 hover:text-red-300 rounded-lg transition-all text-sm"
                >
                  Clear All Tasks
                </button>
              </div>
            )}
          </div>

          {/* Right Column - Task List */}
          <div className="lg:col-span-2">
            <div className="bg-white/5 backdrop-blur-lg rounded-xl border border-white/10 overflow-hidden">
              <div className="px-4 py-3 border-b border-white/10 flex items-center justify-between">
                <h3 className="text-white font-medium">
                  Tasks ({tasks.length})
                </h3>
                {tasks.length > 0 && (
                  <span className="text-purple-300/50 text-xs">
                    Click ✏️ to edit, 🗑️ to delete
                  </span>
                )}
              </div>

              {tasks.length === 0 ? (
                <div className="p-8 text-center text-purple-300/50">
                  <div className="text-4xl mb-2">📋</div>
                  <p>No tasks yet</p>
                  <p className="text-xs mt-1">Add manually or generate with AI</p>
                </div>
              ) : (
                <div className="max-h-[60vh] overflow-y-auto">
                  {tasks.map((task, index) => (
                    <div
                      key={task.id}
                      className="px-4 py-3 border-b border-white/5 hover:bg-white/5 transition-colors"
                    >
                      {editingId === task.id ? (
                        <div className="space-y-2">
                          <input
                            type="text"
                            value={editTitle}
                            onChange={(e) => setEditTitle(e.target.value)}
                            className="w-full px-3 py-2 bg-white/10 border border-white/20 rounded text-white focus:outline-none focus:ring-2 focus:ring-purple-500 text-sm"
                            autoFocus
                          />
                          <textarea
                            value={editDescription}
                            onChange={(e) => setEditDescription(e.target.value)}
                            rows={2}
                            className="w-full px-3 py-2 bg-white/10 border border-white/20 rounded text-white focus:outline-none focus:ring-2 focus:ring-purple-500 resize-none text-sm"
                          />
                          <div className="flex gap-2">
                            <button
                              onClick={handleSaveEdit}
                              className="px-3 py-1.5 bg-green-600 hover:bg-green-700 text-white rounded text-xs"
                            >
                              Save
                            </button>
                            <button
                              onClick={handleCancelEdit}
                              className="px-3 py-1.5 bg-white/10 hover:bg-white/20 text-white rounded text-xs"
                            >
                              Cancel
                            </button>
                          </div>
                        </div>
                      ) : (
                        <div className="flex items-start justify-between gap-3">
                          <div className="flex-1 min-w-0">
                            <div className="flex items-center gap-2">
                              <span className="text-purple-400 text-xs font-mono">
                                #{index + 1}
                              </span>
                              <h4 className="text-white text-sm font-medium truncate">
                                {task.title}
                              </h4>
                            </div>
                            {task.description && (
                              <p className="text-purple-300/60 text-xs mt-0.5 line-clamp-1">
                                {task.description}
                              </p>
                            )}
                          </div>
                          <div className="flex gap-1 flex-shrink-0">
                            <button
                              onClick={() => handleStartEdit(task)}
                              className="p-1 text-purple-300 hover:text-white hover:bg-white/10 rounded transition-all"
                              title="Edit"
                            >
                              ✏️
                            </button>
                            <button
                              onClick={() => handleDeleteTask(task.id)}
                              className="p-1 text-red-400 hover:text-red-300 hover:bg-white/10 rounded transition-all"
                              title="Delete"
                            >
                              🗑️
                            </button>
                          </div>
                        </div>
                      )}
                    </div>
                  ))}
                </div>
              )}
            </div>
          </div>
        </div>
      </main>
    </div>
  );
}