/**
 * Bank Statement extraction using Ministral 3 Vision (Direct)
 *
 * NO OCR pipeline needed - Ministral 3 has built-in vision encoder:
 *   1. Convert PDF to images
 *   2. Send images directly to Ministral 3 via Ollama
 *   3. Extract transactions as structured JSON
 */
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 { ensureMinistral3 } from './helpers/docker.js';

const OLLAMA_URL = 'http://localhost:11434';
const VISION_MODEL = 'ministral-3:8b';

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

/**
 * Convert PDF to PNG images using ImageMagick
 */
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 200 -quality 90 "${pdfPath}" -background white -alpha remove "${outputPattern}"`,
      { stdio: 'pipe' }
    );

    const files = fs.readdirSync(tempDir).filter((f) => 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 });
  }
}

/**
 * Extract transactions from a single page image using Ministral 3 Vision
 */
async function extractTransactionsFromPage(image: string, pageNum: number): Promise<ITransaction[]> {
  console.log(`    [Vision] Processing page ${pageNum}`);

  // JSON schema for array of transactions
  const transactionSchema = {
    type: 'array',
    items: {
      type: 'object',
      properties: {
        date: { type: 'string', description: 'Transaction date in YYYY-MM-DD format' },
        counterparty: { type: 'string', description: 'Name of the other party' },
        amount: { type: 'number', description: 'Amount (negative for debits, positive for credits)' },
      },
      required: ['date', 'counterparty', 'amount'],
    },
  };

  const prompt = `Extract ALL bank transactions from this bank statement page.

For each transaction, extract:
- date: Transaction date in YYYY-MM-DD format
- counterparty: The name/description of the other party (merchant, payee, etc.)
- amount: The amount as a number (NEGATIVE for debits/expenses, POSITIVE for credits/income)

Return a JSON array of transactions. If no transactions visible, return empty array [].
Example: [{"date":"2021-06-01","counterparty":"AMAZON","amount":-50.00}]`;

  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],
        },
      ],
      format: transactionSchema,
      stream: true,
      options: {
        num_predict: 4096,  // Bank statements can have many transactions
        temperature: 0.0,
      },
    }),
  });

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

  const reader = response.body?.getReader();
  if (!reader) {
    throw new Error('No response body');
  }

  const decoder = new TextDecoder();
  let fullText = '';

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

    const chunk = decoder.decode(value, { stream: true });
    const lines = chunk.split('\n').filter((l) => l.trim());

    for (const line of lines) {
      try {
        const json = JSON.parse(line);
        if (json.message?.content) {
          fullText += json.message.content;
        }
      } catch {
        // Skip invalid JSON lines
      }
    }
  }

  // Parse JSON response
  let jsonStr = fullText.trim();

  if (jsonStr.startsWith('```json')) jsonStr = jsonStr.slice(7);
  else if (jsonStr.startsWith('```')) jsonStr = jsonStr.slice(3);
  if (jsonStr.endsWith('```')) jsonStr = jsonStr.slice(0, -3);
  jsonStr = jsonStr.trim();

  // Find array boundaries
  const startIdx = jsonStr.indexOf('[');
  const endIdx = jsonStr.lastIndexOf(']') + 1;

  if (startIdx < 0 || endIdx <= startIdx) {
    console.log(`    [Page ${pageNum}] No transactions found`);
    return [];
  }

  try {
    const parsed = JSON.parse(jsonStr.substring(startIdx, endIdx));
    console.log(`    [Page ${pageNum}] Found ${parsed.length} transactions`);
    return parsed.map((t: { date?: string; counterparty?: string; amount?: number }) => ({
      date: t.date || '',
      counterparty: t.counterparty || '',
      amount: parseFloat(String(t.amount)) || 0,
    }));
  } catch (e) {
    console.log(`    [Page ${pageNum}] Parse error: ${e}`);
    return [];
  }
}

/**
 * Extract all transactions from all pages
 */
async function extractAllTransactions(images: string[]): Promise<ITransaction[]> {
  const allTransactions: ITransaction[] = [];

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

  return allTransactions;
}

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

  // Handle DD/MM/YYYY or DD.MM.YYYY
  const 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;
}

/**
 * Compare extracted transactions vs expected
 */
function compareTransactions(
  extracted: ITransaction[],
  expected: ITransaction[]
): { matchRate: number; matched: number; missed: number; extra: number; errors: string[] } {
  const errors: string[] = [];
  let matched = 0;

  // Normalize all dates
  const normalizedExtracted = extracted.map((t) => ({
    ...t,
    date: normalizeDate(t.date),
    counterparty: t.counterparty.toUpperCase().trim(),
  }));

  const normalizedExpected = expected.map((t) => ({
    ...t,
    date: normalizeDate(t.date),
    counterparty: t.counterparty.toUpperCase().trim(),
  }));

  // Try to match each expected transaction
  const matchedIndices = new Set<number>();

  for (const exp of normalizedExpected) {
    let found = false;

    for (let i = 0; i < normalizedExtracted.length; i++) {
      if (matchedIndices.has(i)) continue;

      const ext = normalizedExtracted[i];

      // Match by date + amount (counterparty names can vary)
      if (ext.date === exp.date && Math.abs(ext.amount - exp.amount) < 0.02) {
        matched++;
        matchedIndices.add(i);
        found = true;
        break;
      }
    }

    if (!found) {
      errors.push(`Missing: ${exp.date} | ${exp.counterparty} | ${exp.amount}`);
    }
  }

  const missed = expected.length - matched;
  const extra = extracted.length - matched;
  const matchRate = expected.length > 0 ? (matched / expected.length) * 100 : 0;

  return { matchRate, matched, missed, extra, errors };
}

/**
 * Find test cases (PDF + JSON pairs 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) => f.endsWith('.pdf'))) {
    const baseName = pdf.replace('.pdf', '');
    const jsonFile = `${baseName}.json`;
    if (files.includes(jsonFile)) {
      // Skip invoice files - only bank statements
      if (!baseName.includes('invoice')) {
        testCases.push({
          name: baseName,
          pdfPath: path.join(testDir, pdf),
          jsonPath: path.join(testDir, jsonFile),
        });
      }
    }
  }

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

// Tests

tap.test('setup: ensure Ministral 3 is running', async () => {
  console.log('\n[Setup] Checking Ministral 3...\n');
  const ok = await ensureMinistral3();
  expect(ok).toBeTrue();
  console.log('\n[Setup] Ready!\n');
});

const testCases = findTestCases();
console.log(`\nFound ${testCases.length} bank statement test cases (Ministral 3 Vision)\n`);

let totalMatched = 0;
let totalExpected = 0;
const times: number[] = [];

for (const testCase of testCases) {
  tap.test(`should extract bank statement: ${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 start = Date.now();
    const images = convertPdfToImages(testCase.pdfPath);
    console.log(`  Pages: ${images.length}`);

    const extracted = await extractAllTransactions(images);
    const elapsed = Date.now() - start;
    times.push(elapsed);

    console.log(`  Extracted: ${extracted.length} transactions`);

    const result = compareTransactions(extracted, expected);
    totalMatched += result.matched;
    totalExpected += expected.length;

    console.log(`  Match rate: ${result.matchRate.toFixed(1)}% (${result.matched}/${expected.length})`);
    console.log(`  Missed: ${result.missed}, Extra: ${result.extra}`);
    console.log(`  Time: ${(elapsed / 1000).toFixed(1)}s`);

    if (result.errors.length > 0 && result.errors.length <= 5) {
      result.errors.forEach((e) => console.log(`    - ${e}`));
    } else if (result.errors.length > 5) {
      console.log(`    (${result.errors.length} missing transactions)`);
    }

    // Consider it a pass if we match at least 70% of transactions
    expect(result.matchRate).toBeGreaterThan(70);
  });
}

tap.test('summary', async () => {
  const overallMatchRate = totalExpected > 0 ? (totalMatched / totalExpected) * 100 : 0;
  const totalTime = times.reduce((a, b) => a + b, 0) / 1000;
  const avgTime = times.length > 0 ? totalTime / times.length : 0;

  console.log(`\n======================================================`);
  console.log(`   Bank Statement Extraction Summary (Ministral 3)`);
  console.log(`======================================================`);
  console.log(`  Method:      Ministral 3 8B Vision (Direct)`);
  console.log(`  Statements:  ${testCases.length}`);
  console.log(`  Matched:     ${totalMatched}/${totalExpected} transactions`);
  console.log(`  Match rate:  ${overallMatchRate.toFixed(1)}%`);
  console.log(`------------------------------------------------------`);
  console.log(`  Total time:  ${totalTime.toFixed(1)}s`);
  console.log(`  Avg per stmt: ${avgTime.toFixed(1)}s`);
  console.log(`======================================================\n`);
});

export default tap.start();