'use client';

import { useState, useCallback } from 'react';
import {
  DataProvider,
  ActionProvider,
  VisibilityProvider,
  useUIStream,
  Renderer,
} from '@json-render/react';
import { componentRegistry } from '@/components/ui';

const INITIAL_DATA = {
  analytics: {
    revenue: 125000,
    growth: 0.15,
    customers: 1234,
    orders: 567,
    salesByRegion: [
      { label: 'US', value: 45000 },
      { label: 'EU', value: 35000 },
      { label: 'Asia', value: 28000 },
      { label: 'Other', value: 17000 },
    ],
    recentTransactions: [
      { id: 'TXN001', customer: 'Acme Corp', amount: 1500, status: 'completed', date: '2024-01-15' },
      { id: 'TXN002', customer: 'Globex Inc', amount: 2300, status: 'pending', date: '2024-01-14' },
      { id: 'TXN003', customer: 'Initech', amount: 890, status: 'completed', date: '2024-01-13' },
      { id: 'TXN004', customer: 'Umbrella Co', amount: 4200, status: 'completed', date: '2024-01-12' },
    ],
  },
  form: {
    dateRange: '',
    region: '',
  },
};

const ACTION_HANDLERS = {
  export_report: () => alert('Exporting report...'),
  refresh_data: () => alert('Refreshing data...'),
  view_details: (params: Record<string, unknown>) => alert(`Details: ${JSON.stringify(params)}`),
  apply_filter: () => alert('Applying filters...'),
};

function DashboardContent() {
  const [prompt, setPrompt] = useState('');
  const { tree, isStreaming, error, send, clear } = useUIStream({
    api: '/api/generate',
    onError: (err) => console.error('Generation error:', err),
  });

  const handleSubmit = useCallback(
    async (e: React.FormEvent) => {
      e.preventDefault();
      if (!prompt.trim()) return;
      await send(prompt, { data: INITIAL_DATA });
    },
    [prompt, send]
  );

  const examples = [
    'Revenue dashboard with metrics and chart',
    'Recent transactions table',
    'Customer count with trend',
  ];

  const hasElements = tree && Object.keys(tree.elements).length > 0;

  return (
    <div style={{ maxWidth: 960, margin: '0 auto', padding: '48px 24px' }}>
      <header style={{ marginBottom: 48 }}>
        <h1 style={{ margin: 0, fontSize: 32, fontWeight: 600, letterSpacing: '-0.02em' }}>
          Dashboard
        </h1>
        <p style={{ margin: '8px 0 0', color: 'var(--muted)', fontSize: 16 }}>
          Generate widgets from prompts. Constrained to your catalog.
        </p>
      </header>

      <form onSubmit={handleSubmit} style={{ marginBottom: 32 }}>
        <div style={{ display: 'flex', gap: 8, marginBottom: 16 }}>
          <input
            type="text"
            value={prompt}
            onChange={(e) => setPrompt(e.target.value)}
            placeholder="Describe what you want..."
            disabled={isStreaming}
            style={{
              flex: 1,
              padding: '12px 16px',
              background: 'var(--card)',
              border: '1px solid var(--border)',
              borderRadius: 'var(--radius)',
              color: 'var(--foreground)',
              fontSize: 16,
              outline: 'none',
            }}
          />
          <button
            type="submit"
            disabled={isStreaming || !prompt.trim()}
            style={{
              padding: '12px 24px',
              background: isStreaming ? 'var(--border)' : 'var(--foreground)',
              color: 'var(--background)',
              border: 'none',
              borderRadius: 'var(--radius)',
              fontSize: 16,
              fontWeight: 500,
              opacity: isStreaming || !prompt.trim() ? 0.5 : 1,
            }}
          >
            {isStreaming ? 'Generating...' : 'Generate'}
          </button>
          {hasElements && (
            <button
              type="button"
              onClick={clear}
              style={{
                padding: '12px 16px',
                background: 'transparent',
                color: 'var(--muted)',
                border: '1px solid var(--border)',
                borderRadius: 'var(--radius)',
                fontSize: 16,
              }}
            >
              Clear
            </button>
          )}
        </div>

        <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
          {examples.map((ex) => (
            <button
              key={ex}
              type="button"
              onClick={() => setPrompt(ex)}
              style={{
                padding: '6px 12px',
                background: 'var(--card)',
                color: 'var(--muted)',
                border: '1px solid var(--border)',
                borderRadius: 'var(--radius)',
                fontSize: 13,
              }}
            >
              {ex}
            </button>
          ))}
        </div>
      </form>

      {error && (
        <div
          style={{
            padding: 16,
            marginBottom: 24,
            background: 'var(--card)',
            border: '1px solid var(--border)',
            borderRadius: 'var(--radius)',
            color: '#ef4444',
            fontSize: 14,
          }}
        >
          {error.message}
        </div>
      )}

      <div
        style={{
          minHeight: 300,
          padding: 24,
          background: 'var(--card)',
          border: '1px solid var(--border)',
          borderRadius: 'var(--radius)',
        }}
      >
        {!hasElements && !isStreaming ? (
          <div style={{ textAlign: 'center', padding: '60px 20px', color: 'var(--muted)' }}>
            <p style={{ margin: 0 }}>Enter a prompt to generate a widget</p>
          </div>
        ) : tree ? (
          <Renderer tree={tree} registry={componentRegistry} loading={isStreaming} />
        ) : null}
      </div>

      {hasElements && (
        <details style={{ marginTop: 24 }}>
          <summary style={{ cursor: 'pointer', fontSize: 14, color: 'var(--muted)' }}>
            View JSON
          </summary>
          <pre
            style={{
              marginTop: 8,
              padding: 16,
              background: 'var(--card)',
              border: '1px solid var(--border)',
              borderRadius: 'var(--radius)',
              overflow: 'auto',
              fontSize: 12,
              color: 'var(--muted)',
            }}
          >
            {JSON.stringify(tree, null, 2)}
          </pre>
        </details>
      )}
    </div>
  );
}

export default function DashboardPage() {
  return (
    <DataProvider initialData={INITIAL_DATA}>
      <VisibilityProvider>
        <ActionProvider handlers={ACTION_HANDLERS}>
          <DashboardContent />
        </ActionProvider>
      </VisibilityProvider>
    </DataProvider>
  );
}