/**
 * Invoice extraction tuning - uses pre-generated markdown files
 *
 * Skips OCR stage, only runs GPT-OSS extraction on existing .debug.md files.
 * Use this to quickly iterate on extraction prompts and logic.
 *
 * Run with: tstest test/test.invoices.extraction.ts --verbose
 */
import { tap, expect } from '@git.zone/tstest/tapbundle';
import * as fs from 'fs';
import * as path from 'path';
import { ensureMiniCpm } from './helpers/docker.js';

const OLLAMA_URL = 'http://localhost:11434';
const EXTRACTION_MODEL = 'gpt-oss:20b';

// Test these specific invoices (must have .debug.md files)
const TEST_INVOICES = [
  'consensus_2021-09',
  'hetzner_2022-04',
  'qonto_2021-08',
  'qonto_2021-09',
];

interface IInvoice {
  invoice_number: string;
  invoice_date: string;
  vendor_name: string;
  currency: string;
  net_amount: number;
  vat_amount: number;
  total_amount: number;
}

interface ITestCase {
  name: string;
  markdownPath: string;
  jsonPath: string;
}

// JSON extraction prompt for GPT-OSS 20B (sent AFTER the invoice text is provided)
const JSON_EXTRACTION_PROMPT = `Extract key fields from the invoice. Return ONLY valid JSON.

WHERE TO FIND DATA:
- invoice_number, invoice_date, vendor_name: Look in the HEADER section at the TOP of PAGE 1 (near "Invoice no.", "Invoice date:", "Rechnungsnummer")
- net_amount, vat_amount, total_amount: Look in the SUMMARY section at the BOTTOM (look for "Total", "Amount due", "Gesamtbetrag")

RULES:
1. invoice_number: Extract ONLY the value (e.g., "R0015632540"), NOT the label "Invoice no."
2. invoice_date: Convert to YYYY-MM-DD format (e.g., "14/04/2022" → "2022-04-14")
3. vendor_name: The company issuing the invoice
4. currency: EUR, USD, or GBP
5. net_amount: Total before tax
6. vat_amount: Tax amount
7. total_amount: Final total with tax

JSON only:
{"invoice_number":"X","invoice_date":"YYYY-MM-DD","vendor_name":"X","currency":"EUR","net_amount":0,"vat_amount":0,"total_amount":0}`;

/**
 * Ensure GPT-OSS 20B model is available
 */
async function ensureExtractionModel(): Promise<boolean> {
  try {
    const response = await fetch(`${OLLAMA_URL}/api/tags`);
    if (response.ok) {
      const data = await response.json();
      const models = data.models || [];
      if (models.some((m: { name: string }) => m.name === EXTRACTION_MODEL)) {
        console.log(`    [Ollama] Model available: ${EXTRACTION_MODEL}`);
        return true;
      }
    }
  } catch {
    return false;
  }

  console.log(`    [Ollama] Pulling ${EXTRACTION_MODEL}...`);
  const pullResponse = await fetch(`${OLLAMA_URL}/api/pull`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ name: EXTRACTION_MODEL, stream: false }),
  });

  return pullResponse.ok;
}

/**
 * Parse amount from string (handles European format)
 */
function parseAmount(s: string | number | undefined): number {
  if (s === undefined || s === null) return 0;
  if (typeof s === 'number') return s;
  const match = s.match(/([\d.,]+)/);
  if (!match) return 0;
  const numStr = match[1];
  const normalized = numStr.includes(',') && numStr.indexOf(',') > numStr.lastIndexOf('.')
    ? numStr.replace(/\./g, '').replace(',', '.')
    : numStr.replace(/,/g, '');
  return parseFloat(normalized) || 0;
}

/**
 * Extract invoice number - minimal normalization
 */
function extractInvoiceNumber(s: string | undefined): string {
  if (!s) return '';
  return s.replace(/\*\*/g, '').replace(/`/g, '').trim();
}

/**
 * Extract date (YYYY-MM-DD) from response
 */
function extractDate(s: string | undefined): string {
  if (!s) return '';
  let clean = s.replace(/\*\*/g, '').replace(/`/g, '').trim();
  const isoMatch = clean.match(/(\d{4}-\d{2}-\d{2})/);
  if (isoMatch) return isoMatch[1];
  const dmyMatch = clean.match(/(\d{1,2})[\/.](\d{1,2})[\/.](\d{4})/);
  if (dmyMatch) {
    return `${dmyMatch[3]}-${dmyMatch[2].padStart(2, '0')}-${dmyMatch[1].padStart(2, '0')}`;
  }
  return clean.replace(/[^\d-]/g, '').trim();
}

/**
 * Extract currency
 */
function extractCurrency(s: string | undefined): string {
  if (!s) return 'EUR';
  const upper = s.toUpperCase();
  if (upper.includes('EUR') || upper.includes('€')) return 'EUR';
  if (upper.includes('USD') || upper.includes('$')) return 'USD';
  if (upper.includes('GBP') || upper.includes('£')) return 'GBP';
  return 'EUR';
}

/**
 * Extract JSON from response
 */
function extractJsonFromResponse(response: string): Record<string, unknown> | null {
  let cleanResponse = response.replace(/<think>[\s\S]*?<\/think>/g, '').trim();
  const codeBlockMatch = cleanResponse.match(/```(?:json)?\s*([\s\S]*?)```/);
  const jsonStr = codeBlockMatch ? codeBlockMatch[1].trim() : cleanResponse;

  try {
    return JSON.parse(jsonStr);
  } catch {
    const jsonMatch = jsonStr.match(/\{[\s\S]*\}/);
    if (jsonMatch) {
      try {
        return JSON.parse(jsonMatch[0]);
      } catch {
        return null;
      }
    }
    return null;
  }
}

/**
 * Parse JSON response into IInvoice
 */
function parseJsonToInvoice(response: string): IInvoice | null {
  const parsed = extractJsonFromResponse(response);
  if (!parsed) return null;

  return {
    invoice_number: extractInvoiceNumber(String(parsed.invoice_number || '')),
    invoice_date: extractDate(String(parsed.invoice_date || '')),
    vendor_name: String(parsed.vendor_name || '').replace(/\*\*/g, '').replace(/`/g, '').trim(),
    currency: extractCurrency(String(parsed.currency || '')),
    net_amount: parseAmount(parsed.net_amount as string | number),
    vat_amount: parseAmount(parsed.vat_amount as string | number),
    total_amount: parseAmount(parsed.total_amount as string | number),
  };
}

/**
 * Extract invoice from markdown using GPT-OSS 20B (streaming)
 */
async function extractInvoiceFromMarkdown(markdown: string, queryId: string): Promise<IInvoice | null> {
  const startTime = Date.now();

  console.log(`      [${queryId}] Invoice: ${markdown.length} chars, Prompt: ${JSON_EXTRACTION_PROMPT.length} chars`);

  const response = await fetch(`${OLLAMA_URL}/api/chat`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      model: EXTRACTION_MODEL,
      messages: [
        { role: 'user', content: 'Hi there, how are you?' },
        { role: 'assistant', content: 'Good, how can I help you today?' },
        { role: 'user', content: `Here is an invoice document:\n\n${markdown}` },
        { role: 'assistant', content: 'I have read the invoice document you provided. I can see all the text content. What would you like me to do with it?' },
        { role: 'user', content: JSON_EXTRACTION_PROMPT },
      ],
      stream: true,
    }),
    signal: AbortSignal.timeout(120000), // 2 min timeout
  });

  if (!response.ok) {
    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
    console.log(`      [${queryId}] ERROR: ${response.status} (${elapsed}s)`);
    throw new Error(`Ollama API error: ${response.status}`);
  }

  // Stream the response
  let content = '';
  let thinkingContent = '';
  let thinkingStarted = false;
  let outputStarted = false;
  const reader = response.body!.getReader();
  const decoder = new TextDecoder();

  try {
    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      const chunk = decoder.decode(value, { stream: true });

      for (const line of chunk.split('\n').filter(l => l.trim())) {
        try {
          const json = JSON.parse(line);

          const thinking = json.message?.thinking || '';
          if (thinking) {
            if (!thinkingStarted) {
              process.stdout.write(`      [${queryId}] THINKING: `);
              thinkingStarted = true;
            }
            process.stdout.write(thinking);
            thinkingContent += thinking;
          }

          const token = json.message?.content || '';
          if (token) {
            if (!outputStarted) {
              if (thinkingStarted) process.stdout.write('\n');
              process.stdout.write(`      [${queryId}] OUTPUT: `);
              outputStarted = true;
            }
            process.stdout.write(token);
            content += token;
          }
        } catch {
          // Ignore parse errors for partial chunks
        }
      }
    }
  } finally {
    if (thinkingStarted || outputStarted) process.stdout.write('\n');
  }

  const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
  console.log(`      [${queryId}] Done: ${thinkingContent.length} thinking, ${content.length} output (${elapsed}s)`);

  return parseJsonToInvoice(content);
}

/**
 * Normalize date to YYYY-MM-DD
 */
function normalizeDate(dateStr: string | null): string {
  if (!dateStr) return '';
  if (/^\d{4}-\d{2}-\d{2}$/.test(dateStr)) return dateStr;

  const monthMap: Record<string, string> = {
    JAN: '01', FEB: '02', MAR: '03', APR: '04', MAY: '05', JUN: '06',
    JUL: '07', AUG: '08', SEP: '09', OCT: '10', NOV: '11', DEC: '12',
  };

  let match = dateStr.match(/^(\d{1,2})-([A-Z]{3})-(\d{4})$/i);
  if (match) {
    return `${match[3]}-${monthMap[match[2].toUpperCase()] || '01'}-${match[1].padStart(2, '0')}`;
  }

  match = dateStr.match(/^(\d{1,2})[\/.](\d{1,2})[\/.](\d{4})$/);
  if (match) {
    return `${match[3]}-${match[2].padStart(2, '0')}-${match[1].padStart(2, '0')}`;
  }

  return dateStr;
}

/**
 * Normalize invoice number for comparison (remove spaces, lowercase)
 */
function normalizeInvoiceNumber(s: string): string {
  return s.replace(/\s+/g, '').toLowerCase();
}

/**
 * Compare extracted invoice against expected
 */
function compareInvoice(
  extracted: IInvoice,
  expected: IInvoice
): { match: boolean; errors: string[] } {
  const errors: string[] = [];

  // Invoice number - normalize spaces for comparison
  const extNum = normalizeInvoiceNumber(extracted.invoice_number || '');
  const expNum = normalizeInvoiceNumber(expected.invoice_number || '');
  if (extNum !== expNum) {
    errors.push(`invoice_number: expected "${expected.invoice_number}", got "${extracted.invoice_number}"`);
  }

  if (normalizeDate(extracted.invoice_date) !== normalizeDate(expected.invoice_date)) {
    errors.push(`invoice_date: expected "${expected.invoice_date}", got "${extracted.invoice_date}"`);
  }

  if (Math.abs(extracted.total_amount - expected.total_amount) > 0.02) {
    errors.push(`total_amount: expected ${expected.total_amount}, got ${extracted.total_amount}`);
  }

  if (extracted.currency?.toUpperCase() !== expected.currency?.toUpperCase()) {
    errors.push(`currency: expected "${expected.currency}", got "${extracted.currency}"`);
  }

  return { match: errors.length === 0, errors };
}

/**
 * Find test cases with existing debug markdown
 */
function findTestCases(): ITestCase[] {
  const invoicesDir = path.join(process.cwd(), '.nogit/invoices');
  if (!fs.existsSync(invoicesDir)) return [];

  const testCases: ITestCase[] = [];

  for (const invoiceName of TEST_INVOICES) {
    const markdownPath = path.join(invoicesDir, `${invoiceName}.debug.md`);
    const jsonPath = path.join(invoicesDir, `${invoiceName}.json`);

    if (fs.existsSync(markdownPath) && fs.existsSync(jsonPath)) {
      testCases.push({
        name: invoiceName,
        markdownPath,
        jsonPath,
      });
    } else {
      if (!fs.existsSync(markdownPath)) {
        console.warn(`Warning: Missing markdown: ${markdownPath}`);
      }
      if (!fs.existsSync(jsonPath)) {
        console.warn(`Warning: Missing JSON: ${jsonPath}`);
      }
    }
  }

  return testCases;
}

// ============ TESTS ============

const testCases = findTestCases();
console.log(`\n========================================`);
console.log(`  EXTRACTION TUNING TEST`);
console.log(`  (Skips OCR, uses existing .debug.md)`);
console.log(`========================================`);
console.log(`  Testing ${testCases.length} invoices:`);
for (const tc of testCases) {
  console.log(`    - ${tc.name}`);
}
console.log(`========================================\n`);

tap.test('Setup Ollama + GPT-OSS 20B', async () => {
  const ollamaOk = await ensureMiniCpm();
  expect(ollamaOk).toBeTrue();

  const extractionOk = await ensureExtractionModel();
  expect(extractionOk).toBeTrue();
});

let passedCount = 0;
let failedCount = 0;

for (const tc of testCases) {
  tap.test(`Extract ${tc.name}`, async () => {
    const expected: IInvoice = JSON.parse(fs.readFileSync(tc.jsonPath, 'utf-8'));
    const markdown = fs.readFileSync(tc.markdownPath, 'utf-8');

    console.log(`\n    ========================================`);
    console.log(`    === ${tc.name} ===`);
    console.log(`    ========================================`);
    console.log(`    EXPECTED: ${expected.invoice_number} | ${expected.invoice_date} | ${expected.total_amount} ${expected.currency}`);
    console.log(`    Markdown: ${markdown.length} chars`);

    const startTime = Date.now();

    const extracted = await extractInvoiceFromMarkdown(markdown, tc.name);

    if (!extracted) {
      failedCount++;
      console.log(`\n    Result: ✗ FAILED TO PARSE (${((Date.now() - startTime) / 1000).toFixed(1)}s)`);
      return;
    }

    const elapsedMs = Date.now() - startTime;

    console.log(`    EXTRACTED: ${extracted.invoice_number} | ${extracted.invoice_date} | ${extracted.total_amount} ${extracted.currency}`);

    const result = compareInvoice(extracted, expected);

    if (result.match) {
      passedCount++;
      console.log(`\n    Result: ✓ MATCH (${(elapsedMs / 1000).toFixed(1)}s)`);
    } else {
      failedCount++;
      console.log(`\n    Result: ✗ MISMATCH (${(elapsedMs / 1000).toFixed(1)}s)`);
      console.log(`    ERRORS:`);
      result.errors.forEach(e => console.log(`      - ${e}`));
    }
  });
}

tap.test('Summary', async () => {
  const totalInvoices = testCases.length;
  const accuracy = totalInvoices > 0 ? (passedCount / totalInvoices) * 100 : 0;

  console.log(`\n========================================`);
  console.log(`   Extraction Tuning Summary`);
  console.log(`========================================`);
  console.log(`  Model:     ${EXTRACTION_MODEL}`);
  console.log(`  Passed:    ${passedCount}/${totalInvoices}`);
  console.log(`  Failed:    ${failedCount}/${totalInvoices}`);
  console.log(`  Accuracy:  ${accuracy.toFixed(1)}%`);
  console.log(`========================================\n`);
});

export default tap.start();