/**
 * Bank statement extraction using Qwen3-VL 8B Vision (Direct)
 *
 * Multi-query approach:
 * 1. First ask how many transactions on each page
 * 2. Then query each transaction individually
 * Single pass, no consensus voting.
 */
import { tap, expect } from '@git.zone/tstest/tapbundle';
import * as fs from 'fs';
import * as path from 'path';
import { execSync } from 'child_process';
import * as os from 'os';
import { ensureMiniCpm } from './helpers/docker.js';

const OLLAMA_URL = 'http://localhost:11434';
const VISION_MODEL = 'qwen3-vl:8b';

interface ITransaction {
  date: string;
  counterparty: string;
  amount: number;
}

/**
 * Convert PDF to PNG images
 */
function convertPdfToImages(pdfPath: string): string[] {
  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'pdf-convert-'));
  const outputPattern = path.join(tempDir, 'page-%d.png');

  try {
    execSync(
      `convert -density 150 -quality 90 "${pdfPath}" -background white -alpha remove "${outputPattern}"`,
      { stdio: 'pipe' }
    );

    const files = fs.readdirSync(tempDir).filter((f: string) => f.endsWith('.png')).sort();
    const images: string[] = [];

    for (const file of files) {
      const imagePath = path.join(tempDir, file);
      const imageData = fs.readFileSync(imagePath);
      images.push(imageData.toString('base64'));
    }

    return images;
  } finally {
    fs.rmSync(tempDir, { recursive: true, force: true });
  }
}

/**
 * Query Qwen3-VL with a simple prompt
 */
async function queryVision(image: string, prompt: string): Promise<string> {
  const response = await fetch(`${OLLAMA_URL}/api/chat`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      model: VISION_MODEL,
      messages: [{
        role: 'user',
        content: prompt,
        images: [image],
      }],
      stream: false,
      options: {
        num_predict: 500,
        temperature: 0.1,
      },
    }),
  });

  if (!response.ok) {
    throw new Error(`Ollama API error: ${response.status}`);
  }

  const data = await response.json();
  return (data.message?.content || '').trim();
}

/**
 * Count transactions on a page
 */
async function countTransactions(image: string, pageNum: number): Promise<number> {
  const response = await queryVision(image,
    `How many transaction rows are in this bank statement table?
Count only the data rows (with dates like "01.01.2024" and amounts like "- 50,00 €").
Do NOT count the header row or summary/total rows.
Answer with just the number, for example: 7`
  );

  console.log(`    [Page ${pageNum}] Count query response: "${response}"`);
  const match = response.match(/(\d+)/);
  const count = match ? parseInt(match[1], 10) : 0;
  console.log(`    [Page ${pageNum}] Parsed count: ${count}`);
  return count;
}

/**
 * Get a single transaction by index (logs immediately when complete)
 */
async function getTransaction(image: string, index: number, pageNum: number): Promise<ITransaction | null> {
  const response = await queryVision(image,
    `This is a bank statement. Look at transaction row #${index} in the table (counting from top, excluding headers).

Extract this transaction's details:
- Date in YYYY-MM-DD format
- Counterparty/description name
- Amount as number (negative for debits like "- 21,47 €" = -21.47, positive for credits like "+ 100,00 €" = 100.00)

Answer in format: DATE|COUNTERPARTY|AMOUNT
Example: 2024-01-15|Amazon|−25.99`
  );

  // Parse the response
  const lines = response.split('\n').filter(l => l.includes('|'));
  const line = lines[lines.length - 1] || response;
  const parts = line.split('|').map(p => p.trim());

  if (parts.length >= 3) {
    // Parse amount - handle various formats
    let amountStr = parts[2].replace(/[€$£\s]/g, '').replace('−', '-').replace('–', '-');
    // European format: comma is decimal
    if (amountStr.includes(',')) {
      amountStr = amountStr.replace(/\./g, '').replace(',', '.');
    }
    const amount = parseFloat(amountStr) || 0;

    const tx = {
      date: parts[0],
      counterparty: parts[1],
      amount: amount,
    };
    // Log immediately as this transaction completes
    console.log(`    [P${pageNum} Tx${index.toString().padStart(2, ' ')}] ${tx.date} | ${tx.counterparty.substring(0, 25).padEnd(25)} | ${tx.amount >= 0 ? '+' : ''}${tx.amount.toFixed(2)}`);
    return tx;
  }

  // Log raw response on parse failure
  console.log(`    [P${pageNum} Tx${index.toString().padStart(2, ' ')}] PARSE FAILED: "${response.replace(/\n/g, ' ').substring(0, 60)}..."`);
  return null;
}

/**
 * Extract transactions from a single page using multi-query approach
 */
async function extractTransactionsFromPage(image: string, pageNum: number): Promise<ITransaction[]> {
  // Step 1: Count transactions
  const count = await countTransactions(image, pageNum);

  if (count === 0) {
    return [];
  }

  // Step 2: Query each transaction (in batches to avoid overwhelming)
  // Each transaction logs itself as it completes
  const transactions: ITransaction[] = [];
  const batchSize = 5;

  for (let start = 1; start <= count; start += batchSize) {
    const end = Math.min(start + batchSize - 1, count);
    const indices = Array.from({ length: end - start + 1 }, (_, i) => start + i);

    // Query batch in parallel - each logs as it completes
    const results = await Promise.all(
      indices.map(i => getTransaction(image, i, pageNum))
    );

    for (const tx of results) {
      if (tx) {
        transactions.push(tx);
      }
    }
  }

  console.log(`    [Page ${pageNum}] Complete: ${transactions.length}/${count} extracted`);
  return transactions;
}

/**
 * Extract all transactions from bank statement
 */
async function extractTransactions(images: string[]): Promise<ITransaction[]> {
  console.log(`    [Vision] Processing ${images.length} page(s) with Qwen3-VL (multi-query)`);

  const allTransactions: ITransaction[] = [];

  for (let i = 0; i < images.length; i++) {
    const pageTransactions = await extractTransactionsFromPage(images[i], i + 1);
    allTransactions.push(...pageTransactions);
  }

  console.log(`    [Vision] Total: ${allTransactions.length} transactions`);
  return allTransactions;
}

/**
 * Compare transactions
 */
function compareTransactions(
  extracted: ITransaction[],
  expected: ITransaction[]
): { matches: number; total: number; errors: string[] } {
  const errors: string[] = [];
  let matches = 0;

  for (let i = 0; i < expected.length; i++) {
    const exp = expected[i];
    const ext = extracted[i];

    if (!ext) {
      errors.push(`Missing transaction ${i}: ${exp.date} ${exp.counterparty}`);
      continue;
    }

    const dateMatch = ext.date === exp.date;
    const amountMatch = Math.abs(ext.amount - exp.amount) < 0.01;

    if (dateMatch && amountMatch) {
      matches++;
    } else {
      errors.push(`Mismatch at ${i}: expected ${exp.date}/${exp.amount}, got ${ext.date}/${ext.amount}`);
    }
  }

  if (extracted.length > expected.length) {
    errors.push(`Extra transactions: ${extracted.length - expected.length}`);
  }

  return { matches, total: expected.length, errors };
}

/**
 * Find test cases in .nogit/
 */
function findTestCases(): Array<{ name: string; pdfPath: string; jsonPath: string }> {
  const testDir = path.join(process.cwd(), '.nogit');
  if (!fs.existsSync(testDir)) return [];

  const files = fs.readdirSync(testDir);
  const testCases: Array<{ name: string; pdfPath: string; jsonPath: string }> = [];

  for (const pdf of files.filter((f: string) => f.endsWith('.pdf'))) {
    const baseName = pdf.replace('.pdf', '');
    const jsonFile = `${baseName}.json`;
    if (files.includes(jsonFile)) {
      testCases.push({
        name: baseName,
        pdfPath: path.join(testDir, pdf),
        jsonPath: path.join(testDir, jsonFile),
      });
    }
  }

  return testCases.sort((a, b) => a.name.localeCompare(b.name));
}

/**
 * Ensure Qwen3-VL model is available
 */
async function ensureQwen3Vl(): 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 === VISION_MODEL)) {
        console.log(`[Ollama] Model available: ${VISION_MODEL}`);
        return true;
      }
    }
  } catch {
    return false;
  }

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

  return pullResponse.ok;
}

// Tests

tap.test('setup: ensure Qwen3-VL is running', async () => {
  console.log('\n[Setup] Checking Qwen3-VL 8B...\n');
  const ollamaOk = await ensureMiniCpm();
  expect(ollamaOk).toBeTrue();
  const visionOk = await ensureQwen3Vl();
  expect(visionOk).toBeTrue();
  console.log('\n[Setup] Ready!\n');
});

const testCases = findTestCases();
console.log(`\nFound ${testCases.length} bank statement test cases (Qwen3-VL)\n`);

let passedCount = 0;
let failedCount = 0;

for (const testCase of testCases) {
  tap.test(`should extract: ${testCase.name}`, async () => {
    const expected: ITransaction[] = JSON.parse(fs.readFileSync(testCase.jsonPath, 'utf-8'));
    console.log(`\n=== ${testCase.name} ===`);
    console.log(`Expected: ${expected.length} transactions`);

    const images = convertPdfToImages(testCase.pdfPath);
    console.log(`  Pages: ${images.length}`);

    const extracted = await extractTransactions(images);
    console.log(`  Extracted: ${extracted.length} transactions`);

    const result = compareTransactions(extracted, expected);
    const accuracy = result.total > 0 ? result.matches / result.total : 0;

    if (accuracy >= 0.95 && extracted.length === expected.length) {
      passedCount++;
      console.log(`  Result: PASS (${result.matches}/${result.total})`);
    } else {
      failedCount++;
      console.log(`  Result: FAIL (${result.matches}/${result.total})`);
      result.errors.slice(0, 5).forEach((e) => console.log(`    - ${e}`));
    }

    expect(accuracy).toBeGreaterThan(0.95);
    expect(extracted.length).toEqual(expected.length);
  });
}

tap.test('summary', async () => {
  const total = testCases.length;
  console.log(`\n======================================================`);
  console.log(`   Bank Statement Summary (Qwen3-VL Vision)`);
  console.log(`======================================================`);
  console.log(`  Method:   Multi-query (count then extract each)`);
  console.log(`  Passed:   ${passedCount}/${total}`);
  console.log(`  Failed:   ${failedCount}/${total}`);
  console.log(`======================================================\n`);
});

export default tap.start();