import * as fs from 'node:fs';
import * as path from 'node:path';
// ── Configuration ──────────────────────────────────────────────────────────
const MAX_ENTRY_POINTS = 200;
const MAX_SAMPLED_FILES = 40;
const MAX_LINES_PER_FILE = 80;
const MAX_OUTPUT_BYTES = 512 * 1024; // 512 KB
const ENTRY_POINT_PATTERNS = [
    // HTTP routes
    {
        type: 'http',
        description: 'Express/Koa route',
        pattern: /(?:app|router|server)\s*\.\s*(?:get|post|put|patch|delete|all|use)\s*\(\s*['"]([^'"]*?)['"]/gi,
    },
    {
        type: 'http',
        description: 'Decorator route (Flask/FastAPI/NestJS)',
        pattern: /@(?:app\.)?(?:route|get|post|put|patch|delete|api_view|RequestMapping|GetMapping|PostMapping)\s*\(\s*['"]([^'"]*?)['"]/gi,
    },
    {
        type: 'http',
        description: 'Next.js/Remix route handler',
        pattern: /export\s+(?:async\s+)?function\s+(GET|POST|PUT|PATCH|DELETE|HEAD|OPTIONS)\b/g,
    },
    // CLI
    {
        type: 'cli',
        description: 'CLI command',
        pattern: /\.command\s*\(\s*['"]([\w\-:]+)['"]/g,
    },
    {
        type: 'cli',
        description: 'argparse subparser',
        pattern: /add_parser\s*\(\s*['"]([\w\-]+)['"]/g,
    },
    // Event handlers
    {
        type: 'event',
        description: 'Event listener',
        pattern: /\.on\s*\(\s*['"]([\w\-:.]+)['"]/g,
    },
    {
        type: 'event',
        description: 'Event subscriber decorator',
        pattern: /@(?:EventHandler|Subscribe|Listener|on_event)\s*\(\s*['"]([\w\-:.]+)['"]/g,
    },
    // Cron / scheduled
    {
        type: 'cron',
        description: 'Cron schedule',
        pattern: /@?(?:Cron|Schedule|Scheduled|crontab)\s*\(\s*['"]([^'"]+)['"]/gi,
    },
    // GraphQL
    {
        type: 'http',
        description: 'GraphQL resolver',
        pattern: /@(?:Query|Mutation|Subscription|Resolver)\s*\(/g,
    },
    // Exported handlers (generic)
    {
        type: 'manual',
        description: 'Exported handler',
        pattern: /export\s+(?:async\s+)?function\s+(handle\w+|process\w+|on\w+)\b/g,
    },
];
// Regex to identify test files
const TEST_FILE_PATTERN = /(?:\.test\.|\.spec\.|__tests__|_test\.py|test_\w+\.py)/;
// ── Metadata files ────────────────────────────────────────────────────────
const METADATA_FILES = [
    'package.json',
    'Cargo.toml',
    'go.mod',
    'pyproject.toml',
    'setup.py',
    'setup.cfg',
    'pom.xml',
    'build.gradle',
    'Gemfile',
    'composer.json',
    'mix.exs',
    'Makefile',
    'docker-compose.yml',
    'docker-compose.yaml',
    'README.md',
    'README.rst',
    'README.txt',
    'README',
];
// ── Priority keywords for file signature selection ────────────────────────
const PRIORITY_KEYWORDS = [
    'controller',
    'service',
    'handler',
    'router',
    'route',
    'api',
    'model',
    'entity',
    'repository',
    'usecase',
    'use_case',
    'command',
    'query',
    'event',
    'subscriber',
    'listener',
    'middleware',
    'guard',
    'interceptor',
    'resolver',
    'workflow',
    'flow',
    'process',
    'pipeline',
    'job',
    'task',
];
// ── Entry point detection ──────────────────────────────────────────────────
/**
 * Detects entry points in the given files by scanning for known patterns.
 */
export function detectEntryPoints(targetPath, files) {
    const entryPoints = [];
    for (const file of files) {
        if (entryPoints.length >= MAX_ENTRY_POINTS)
            break;
        // Skip test files
        if (TEST_FILE_PATTERN.test(file.relativePath))
            continue;
        let content;
        try {
            content = fs.readFileSync(file.path, 'utf-8');
        }
        catch {
            continue;
        }
        const lines = content.split('\n');
        for (const patternDef of ENTRY_POINT_PATTERNS) {
            if (entryPoints.length >= MAX_ENTRY_POINTS)
                break;
            // Reset regex lastIndex for global patterns
            patternDef.pattern.lastIndex = 0;
            let match;
            while ((match = patternDef.pattern.exec(content)) !== null) {
                if (entryPoints.length >= MAX_ENTRY_POINTS)
                    break;
                // Find line number
                const lineNo = content.slice(0, match.index).split('\n').length;
                // Extract snippet (5 lines around the match)
                const startLine = Math.max(0, lineNo - 1);
                const endLine = Math.min(lines.length, startLine + 5);
                const snippet = lines.slice(startLine, endLine).join('\n');
                entryPoints.push({
                    file: file.relativePath,
                    line: lineNo,
                    type: patternDef.type,
                    description: patternDef.description,
                    match: match[0].slice(0, 120),
                    snippet: snippet.slice(0, 300),
                });
            }
        }
    }
    return entryPoints;
}
// ── File signature extraction ─────────────────────────────────────────────
/**
 * Computes a priority score for a file path based on business-logic keywords.
 */
function priorityScore(filePath) {
    const lower = filePath.toLowerCase();
    let score = 0;
    for (const kw of PRIORITY_KEYWORDS) {
        if (lower.includes(kw)) {
            score += 1;
        }
    }
    return score;
}
/**
 * Extracts file signatures from the top prioritized files.
 */
export function extractFileSignatures(targetPath, files) {
    const signatures = [];
    // Sort by priority score (highest first)
    const sorted = [...files].sort((a, b) => priorityScore(b.relativePath) - priorityScore(a.relativePath));
    for (const file of sorted.slice(0, MAX_SAMPLED_FILES)) {
        let content;
        try {
            content = fs.readFileSync(file.path, 'utf-8');
        }
        catch {
            continue;
        }
        const allLines = content.split('\n');
        const firstLines = allLines.slice(0, MAX_LINES_PER_FILE);
        const truncated = firstLines.join('\n');
        // Extract exports (JS/TS)
        const jsExports = [
            ...truncated.matchAll(/export\s+(?:default\s+)?(?:async\s+)?(?:function|class|const|let|var|interface|type|enum)\s+(\w+)/g),
        ].map(m => m[1]);
        // Extract exports (Python: module-level def/class)
        let exports = jsExports;
        if (exports.length === 0) {
            exports = [...truncated.matchAll(/^(?:def|class)\s+(\w+)/gm)].map(m => m[1]);
        }
        // Extract imports (first 20)
        const importMatches = [
            ...truncated.matchAll(/(?:import\s+.*?from\s+['"]([^'"]+)['"]|from\s+([\w.]+)\s+import)/g),
        ];
        const imports = importMatches.map(m => m[1] || m[2]).slice(0, 20);
        signatures.push({
            file: file.relativePath,
            exports: exports.slice(0, 20),
            imports,
            lines: allLines.length,
            preview: truncated.slice(0, 500),
        });
    }
    return signatures;
}
// ── Metadata extraction ───────────────────────────────────────────────────
/**
 * Reads project metadata from manifest files.
 */
export function extractMetadata(targetPath) {
    const metadata = {};
    for (const filename of METADATA_FILES) {
        const filepath = path.join(targetPath, filename);
        let content;
        try {
            content = fs.readFileSync(filepath, 'utf-8');
        }
        catch {
            continue;
        }
        if (filename === 'package.json') {
            try {
                const pkg = JSON.parse(content);
                metadata['package.json'] = {
                    name: pkg.name ?? null,
                    description: pkg.description ?? null,
                    scripts: Object.keys(pkg.scripts || {}),
                    dependencies: Object.keys(pkg.dependencies || {}),
                    devDependencies: Object.keys(pkg.devDependencies || {}),
                };
            }
            catch {
                metadata['package.json'] = content.slice(0, 500);
            }
        }
        else if (filename.endsWith('.md') || filename.endsWith('.rst') || filename.endsWith('.txt') || filename === 'README') {
            metadata[filename] = content.slice(0, 2000);
        }
        else if (filename.endsWith('.toml') || filename.endsWith('.cfg') || filename.endsWith('.mod')) {
            metadata[filename] = content.slice(0, 1000);
        }
        else if (filename.endsWith('.json') ||
            filename.endsWith('.yml') ||
            filename.endsWith('.yaml') ||
            filename.endsWith('.xml') ||
            filename.endsWith('.gradle')) {
            metadata[filename] = content.slice(0, 1000);
        }
        else {
            metadata[filename] = content.slice(0, 1000);
        }
    }
    return metadata;
}
// ── Truncation ────────────────────────────────────────────────────────────
/**
 * Progressively trims the domain context to fit within maxBytes.
 */
export function truncateToFit(context, maxBytes = MAX_OUTPUT_BYTES) {
    let output = JSON.stringify(context, null, 2);
    if (Buffer.byteLength(output, 'utf-8') <= maxBytes) {
        return context;
    }
    // 1. Trim file tree to first 200 entries
    context.fileTree = context.fileTree.slice(0, 200);
    output = JSON.stringify(context, null, 2);
    if (Buffer.byteLength(output, 'utf-8') <= maxBytes) {
        return context;
    }
    // 2. Trim previews in signatures to 200 chars
    for (const sig of context.fileSignatures) {
        sig.preview = sig.preview.slice(0, 200);
    }
    output = JSON.stringify(context, null, 2);
    if (Buffer.byteLength(output, 'utf-8') <= maxBytes) {
        return context;
    }
    // 3. Trim snippets in entry points to 100 chars
    for (const ep of context.entryPoints) {
        ep.snippet = ep.snippet.slice(0, 100);
    }
    output = JSON.stringify(context, null, 2);
    if (Buffer.byteLength(output, 'utf-8') <= maxBytes) {
        return context;
    }
    // 4. Reduce signatures to 20 and entry points to 100
    context.fileSignatures = context.fileSignatures.slice(0, 20);
    context.entryPoints = context.entryPoints.slice(0, 100);
    return context;
}
// ── Main function ─────────────────────────────────────────────────────────
/**
 * Generates the domain context for a project.
 *
 * @param targetPath - Absolute path to the project root
 * @param files - Already-scanned file entries from the analyzer
 * @returns The generated DomainContext
 */
export function generateDomainContext(targetPath, files) {
    const fileTree = files.map(f => f.relativePath);
    const entryPoints = detectEntryPoints(targetPath, files);
    const fileSignatures = extractFileSignatures(targetPath, files);
    const metadata = extractMetadata(targetPath);
    let context = {
        projectRoot: targetPath,
        fileCount: files.length,
        fileTree,
        entryPoints,
        fileSignatures,
        metadata,
    };
    context = truncateToFit(context);
    return context;
}