import { db } from '@/lib/db';
import { hashPassword, generateApiKey } from '@/lib/auth';
import { NextResponse } from 'next/server';

export async function GET() {
  try {
    // Upsert demo user
    const hashedPw = await hashPassword('demo1234');
    const apiKey = generateApiKey();

    const user = await db.user.upsert({
      where: { email: 'demo@omniparse.ai' },
      update: {},
      create: {
        email: 'demo@omniparse.ai',
        name: 'Demo User',
        password: hashedPw,
        plan: 'pro',
        apiKey,
      },
    });

    // Delete any existing invoices for this user
    await db.invoice.deleteMany({
      where: { userId: user.id },
    });

    // Define 20 diverse invoices
    const invoiceData = [
      // ── January 2025 (5 invoices) ──
      {
        vendor: 'Acme Corp',
        invNumber: 'INV-2024-001',
        invDate: '2025-01-05',
        dueDate: '2025-02-04',
        amount: 1200,
        vatPct: 0.20,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.95,
        filename: 'invoice_acme_jan.pdf',
        createdAt: new Date('2025-01-06T09:15:00Z'),
      },
      {
        vendor: 'TechVision Inc',
        invNumber: 'INV-2024-002',
        invDate: '2025-01-12',
        dueDate: '2025-02-11',
        amount: 3450,
        vatPct: 0.21,
        currency: 'EUR',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.97,
        filename: 'invoice_techvision_jan.pdf',
        createdAt: new Date('2025-01-13T14:30:00Z'),
      },
      {
        vendor: 'Global Supplies Ltd',
        invNumber: 'INV-2024-003',
        invDate: '2025-01-18',
        dueDate: '2025-02-17',
        amount: 890,
        vatPct: 0.15,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.92,
        filename: 'receipt_global_jan.png',
        createdAt: new Date('2025-01-19T11:00:00Z'),
      },
      {
        vendor: 'CloudNine Services',
        invNumber: 'INV-2024-004',
        invDate: '2025-01-22',
        dueDate: '2025-02-21',
        amount: 5200,
        vatPct: 0.20,
        currency: 'USD',
        status: 'review' as const,
        isDuplicate: false,
        confidence: 0.88,
        filename: 'invoice_cloudnine_jan.pdf',
        createdAt: new Date('2025-01-23T08:45:00Z'),
      },
      {
        vendor: 'DataFlow Systems',
        invNumber: 'INV-2024-005',
        invDate: '2025-01-28',
        dueDate: '2025-02-27',
        amount: 750,
        vatPct: 0.10,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.96,
        filename: 'receipt_dataflow_jan.pdf',
        createdAt: new Date('2025-01-29T16:20:00Z'),
      },

      // ── February 2025 (5 invoices) ──
      {
        vendor: 'Pinnacle Solutions',
        invNumber: 'INV-2024-006',
        invDate: '2025-02-03',
        dueDate: '2025-03-05',
        amount: 1250,
        vatPct: 0.18,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.94,
        filename: 'invoice_pinnacle_feb.pdf',
        createdAt: new Date('2025-02-04T10:00:00Z'),
      },
      {
        vendor: 'TechVision Inc',
        invNumber: 'INV-2024-007',
        invDate: '2025-02-08',
        dueDate: '2025-03-10',
        amount: 2100,
        vatPct: 0.20,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.98,
        filename: 'invoice_techvision_feb.pdf',
        createdAt: new Date('2025-02-09T13:15:00Z'),
      },
      {
        vendor: 'Acme Corp',
        invNumber: 'INV-2024-008',
        invDate: '2025-02-14',
        dueDate: '2025-03-16',
        amount: 8750,
        vatPct: 0.20,
        currency: 'GBP',
        status: 'review' as const,
        isDuplicate: false,
        confidence: 0.87,
        filename: 'invoice_acme_feb.pdf',
        createdAt: new Date('2025-02-15T09:30:00Z'),
      },
      {
        vendor: 'Meridian Group',
        invNumber: 'INV-2024-009',
        invDate: '2025-02-20',
        dueDate: '2025-03-22',
        amount: 430,
        vatPct: 0.12,
        currency: 'USD',
        status: 'pending' as const,
        isDuplicate: false,
        confidence: 0.99,
        filename: 'receipt_meridian_feb.png',
        createdAt: new Date('2025-02-21T15:45:00Z'),
      },
      {
        vendor: 'Nexus Technologies',
        invNumber: 'INV-2024-010',
        invDate: '2025-02-26',
        dueDate: '2025-03-28',
        amount: 6300,
        vatPct: 0.25,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.91,
        filename: 'invoice_nexus_feb.pdf',
        createdAt: new Date('2025-02-27T11:10:00Z'),
      },

      // ── March 2025 (5 invoices) ──
      {
        vendor: 'CloudNine Services',
        invNumber: 'INV-2024-011',
        invDate: '2025-03-04',
        dueDate: '2025-04-03',
        amount: 4800,
        vatPct: 0.20,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.93,
        filename: 'invoice_cloudnine_mar.pdf',
        createdAt: new Date('2025-03-05T08:00:00Z'),
      },
      {
        vendor: 'Pinnacle Solutions',
        invNumber: 'INV-2024-012',
        invDate: '2025-03-10',
        dueDate: '2025-04-09',
        amount: 15000,
        vatPct: 0.22,
        currency: 'USD',
        status: 'review' as const,
        isDuplicate: false,
        confidence: 0.86,
        filename: 'invoice_pinnacle_mar.pdf',
        createdAt: new Date('2025-03-11T14:25:00Z'),
      },
      {
        vendor: 'Global Supplies Ltd',
        invNumber: 'INV-2024-013',
        invDate: '2025-03-15',
        dueDate: '2025-04-14',
        amount: 2350,
        vatPct: 0.19,
        currency: 'EUR',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.95,
        filename: 'invoice_global_mar.pdf',
        createdAt: new Date('2025-03-16T10:40:00Z'),
      },
      {
        vendor: 'DataFlow Systems',
        invNumber: 'INV-2024-014',
        invDate: '2025-03-19',
        dueDate: '2025-04-18',
        amount: 1100,
        vatPct: 0.15,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.97,
        filename: 'receipt_dataflow_mar.png',
        createdAt: new Date('2025-03-20T09:55:00Z'),
      },
      {
        vendor: 'Acme Corp',
        invNumber: 'INV-2024-015',
        invDate: '2025-03-25',
        dueDate: '2025-04-24',
        amount: 9200,
        vatPct: 0.20,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.89,
        filename: 'invoice_acme_mar.pdf',
        createdAt: new Date('2025-03-26T16:30:00Z'),
      },

      // ── April 2025 (5 invoices) ──
      {
        vendor: 'Nexus Technologies',
        invNumber: 'INV-2024-016',
        invDate: '2025-04-02',
        dueDate: '2025-05-02',
        amount: 6280,
        vatPct: 0.23,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: true, // Duplicate of INV-2024-010 (same vendor, $6300)
        confidence: 0.88,
        filename: 'invoice_nexus_apr.pdf',
        createdAt: new Date('2025-04-03T11:20:00Z'),
      },
      {
        vendor: 'Meridian Group',
        invNumber: 'INV-2024-017',
        invDate: '2025-04-08',
        dueDate: '2025-05-08',
        amount: 780,
        vatPct: 0.14,
        currency: 'EUR',
        status: 'pending' as const,
        isDuplicate: false,
        confidence: 0.96,
        filename: 'receipt_meridian_apr.png',
        createdAt: new Date('2025-04-09T08:10:00Z'),
      },
      {
        vendor: 'CloudNine Services',
        invNumber: 'INV-2024-018',
        invDate: '2025-04-14',
        dueDate: '2025-05-14',
        amount: 5150,
        vatPct: 0.20,
        currency: 'USD',
        status: 'done' as const,
        isDuplicate: true, // Duplicate of INV-2024-004 (same vendor, $5200)
        confidence: 0.92,
        filename: 'invoice_cloudnine_apr.pdf',
        createdAt: new Date('2025-04-15T13:50:00Z'),
      },
      {
        vendor: 'Pinnacle Solutions',
        invNumber: 'INV-2024-019',
        invDate: '2025-04-20',
        dueDate: '2025-05-20',
        amount: 3200,
        vatPct: 0.20,
        currency: 'GBP',
        status: 'done' as const,
        isDuplicate: false,
        confidence: 0.94,
        filename: 'invoice_pinnacle_apr.pdf',
        createdAt: new Date('2025-04-21T10:05:00Z'),
      },
      {
        vendor: 'TechVision Inc',
        invNumber: 'INV-2024-020',
        invDate: '2025-04-27',
        dueDate: '2025-05-27',
        amount: 2800,
        vatPct: 0.17,
        currency: 'USD',
        status: 'review' as const,
        isDuplicate: false,
        confidence: 0.85,
        filename: 'invoice_techvision_apr.pdf',
        createdAt: new Date('2025-04-28T15:00:00Z'),
      },
    ];

    // Create all invoices with computed VAT and total
    const invoices = await db.invoice.createMany({
      data: invoiceData.map((inv) => ({
        userId: user.id,
        vendor: inv.vendor,
        invNumber: inv.invNumber,
        invDate: inv.invDate,
        dueDate: inv.dueDate,
        amount: inv.amount,
        vatAmount: Math.round(inv.amount * inv.vatPct * 100) / 100,
        total: Math.round(inv.amount * (1 + inv.vatPct) * 100) / 100,
        currency: inv.currency,
        status: inv.status,
        isDuplicate: inv.isDuplicate,
        confidence: inv.confidence,
        filename: inv.filename,
        rawJson: null,
        createdAt: inv.createdAt,
      })),
    });

    return NextResponse.json({
      message: `Seed complete: ${invoices.count} invoices created for demo user`,
      userId: user.id,
      invoiceCount: invoices.count,
      breakdown: {
        byVendor: {
          'Acme Corp': 3,
          'TechVision Inc': 3,
          'Global Supplies Ltd': 2,
          'CloudNine Services': 3,
          'DataFlow Systems': 2,
          'Pinnacle Solutions': 3,
          'Meridian Group': 2,
          'Nexus Technologies': 2,
        },
        byStatus: { done: 14, review: 4, pending: 2 },
        duplicates: 2,
        byCurrency: { USD: 15, EUR: 3, GBP: 2 },
      },
    });
  } catch (error) {
    console.error('[SEED_ERROR]', error);
    return NextResponse.json({ error: 'Seed failed' }, { status: 500 });
  }
}