import * as fs from 'node:fs';
import * as path from 'node:path';
import { execSync } from 'node:child_process';
import { scanProject } from './scanner.js';
import { parseFile } from './parser.js';
import { buildGraph } from './graph-builder.js';
import { detectLayers } from './layer-detector.js';
import { buildTour } from './tour-builder.js';
/**
 * Reads the existing meta.json from the target path.
 * Returns null if the file doesn't exist or can't be parsed.
 */
function readExistingMeta(targetPath) {
    try {
        const metaPath = path.join(targetPath, '.understand-anything', 'meta.json');
        const content = fs.readFileSync(metaPath, 'utf-8');
        return JSON.parse(content);
    }
    catch {
        return null;
    }
}
/**
 * Gets the list of files changed since a given git commit hash.
 * Returns null if git diff fails or the commit is not found.
 */
function getChangedFiles(targetPath, sinceCommit) {
    try {
        const output = execSync(`git diff --name-only ${sinceCommit} HEAD`, {
            cwd: targetPath,
            encoding: 'utf-8',
            stdio: ['pipe', 'pipe', 'pipe'],
        });
        const files = output.trim().split('\n').filter(f => f.length > 0);
        return files.length > 0 ? files : null;
    }
    catch {
        return null;
    }
}
/**
 * Reads the existing knowledge-graph.json and extracts nodes and edges.
 * Returns null if the file doesn't exist or can't be parsed.
 */
function readExistingGraph(targetPath) {
    try {
        const graphPath = path.join(targetPath, '.understand-anything', 'knowledge-graph.json');
        const content = fs.readFileSync(graphPath, 'utf-8');
        const data = JSON.parse(content);
        if (data.nodes && data.edges) {
            return { nodes: data.nodes, edges: data.edges };
        }
        return null;
    }
    catch {
        return null;
    }
}
/**
 * Computes statistics from the analysis results.
 */
function computeStats(filesAnalyzed, nodes, edges, layers) {
    const nodesByType = {};
    for (const node of nodes) {
        nodesByType[node.type] = (nodesByType[node.type] || 0) + 1;
    }
    return {
        filesAnalyzed,
        nodesByType,
        edgesCreated: edges.length,
        layersIdentified: layers.length,
    };
}
/**
 * Creates an empty result with zero stats.
 */
function createEmptyResult() {
    const emptyMetadata = {
        name: '',
        description: '',
        languages: [],
        frameworks: [],
        analyzedAt: new Date().toISOString(),
        gitCommitHash: '',
    };
    return {
        dashboard: {
            version: '1.0.0',
            project: emptyMetadata,
            nodes: [],
            edges: [],
            layers: [],
            tour: [],
        },
        stats: {
            filesAnalyzed: 0,
            nodesByType: {},
            edgesCreated: 0,
            layersIdentified: 0,
        },
        files: [],
    };
}
/**
 * Parses all files and returns a map of relativePath → ParseResult.
 * Skips files that fail to parse (logs warning to stderr).
 */
function parseFiles(files) {
    const parseResults = new Map();
    for (const file of files) {
        try {
            const result = parseFile(file.path, file.language);
            parseResults.set(file.relativePath, result);
        }
        catch (err) {
            const message = err instanceof Error ? err.message : String(err);
            process.stderr.write(`Warning: Failed to parse ${file.relativePath}: ${message}\n`);
        }
    }
    return parseResults;
}
/**
 * Runs the full analysis pipeline on all files.
 */
function runFullPipeline(scanResult) {
    const { files, metadata } = scanResult;
    if (files.length === 0) {
        return createEmptyResult();
    }
    // Parse all files
    const parseResults = parseFiles(files);
    // Build graph
    const { nodes, edges } = buildGraph(files, parseResults);
    // Detect layers
    const layers = detectLayers(nodes, edges);
    // Build tour
    const tour = buildTour(nodes, edges, layers);
    // Assemble dashboard
    const dashboard = {
        version: '1.0.0',
        project: {
            ...metadata,
            analyzedAt: new Date().toISOString(),
        },
        nodes,
        edges,
        layers,
        tour,
    };
    const stats = computeStats(files.length, nodes, edges, layers);
    return { dashboard, stats, files };
}
/**
 * Main entry point for the static analysis engine.
 *
 * Scans the target directory, parses source files, builds a knowledge graph,
 * detects architectural layers, and generates a guided tour — all without
 * requiring an AI agent.
 *
 * Supports incremental mode: when an existing meta.json is found and --full
 * is not specified, only re-analyzes files changed since the last commit hash.
 *
 * @param targetPath - Absolute path to the directory to analyze
 * @param options - Analysis options (e.g., full rebuild vs incremental)
 * @returns AnalyzeResult with the generated dashboard and statistics
 */
export async function analyze(targetPath, options) {
    try {
        // Scan the project
        const scanResult = scanProject(targetPath);
        if (scanResult.files.length === 0) {
            return createEmptyResult();
        }
        // Determine if we should use incremental mode
        if (!options.full) {
            const existingMeta = readExistingMeta(targetPath);
            if (existingMeta && existingMeta.gitCommitHash) {
                const changedFiles = getChangedFiles(targetPath, existingMeta.gitCommitHash);
                if (changedFiles) {
                    // Attempt incremental analysis
                    const incrementalResult = runIncrementalPipeline(targetPath, scanResult, changedFiles);
                    if (incrementalResult) {
                        return incrementalResult;
                    }
                    // Fall through to full rebuild if incremental fails
                }
            }
        }
        // Full rebuild
        return runFullPipeline(scanResult);
    }
    catch (err) {
        const message = err instanceof Error ? err.message : String(err);
        process.stderr.write(`Error during analysis: ${message}\n`);
        return createEmptyResult();
    }
}
/**
 * Runs incremental analysis: only re-parses changed files, reuses existing
 * nodes/edges for unchanged files, then rebuilds the full graph.
 *
 * Returns null if incremental analysis cannot be completed (caller should
 * fall back to full rebuild).
 */
function runIncrementalPipeline(targetPath, scanResult, changedFiles) {
    // Read existing graph for unchanged file data
    const existingGraph = readExistingGraph(targetPath);
    if (!existingGraph) {
        return null; // Fall back to full rebuild
    }
    const changedSet = new Set(changedFiles);
    const { files, metadata } = scanResult;
    // Split files into changed and unchanged
    const changedFileEntries = files.filter(f => changedSet.has(f.relativePath));
    const unchangedFileEntries = files.filter(f => !changedSet.has(f.relativePath));
    // Parse only changed files
    const changedParseResults = parseFiles(changedFileEntries);
    // For unchanged files, we need their parse results too for graph building.
    // Re-parse them (this is cheaper than storing full parse results in the graph).
    const unchangedParseResults = parseFiles(unchangedFileEntries);
    // Combine all parse results
    const allParseResults = new Map();
    for (const [key, value] of changedParseResults) {
        allParseResults.set(key, value);
    }
    for (const [key, value] of unchangedParseResults) {
        allParseResults.set(key, value);
    }
    // Rebuild the full graph from combined results
    const { nodes, edges } = buildGraph(files, allParseResults);
    // Detect layers
    const layers = detectLayers(nodes, edges);
    // Build tour
    const tour = buildTour(nodes, edges, layers);
    // Assemble dashboard
    const dashboard = {
        version: '1.0.0',
        project: {
            ...metadata,
            analyzedAt: new Date().toISOString(),
        },
        nodes,
        edges,
        layers,
        tour,
    };
    // Stats reflect only the changed files as "analyzed"
    const stats = computeStats(changedFileEntries.length, nodes, edges, layers);
    return { dashboard, stats, files };
}
export { scanProject } from './scanner.js';
export { parseFile } from './parser.js';
export { buildGraph } from './graph-builder.js';
export { detectLayers } from './layer-detector.js';
export { buildTour } from './tour-builder.js';
export { generateDomainContext } from './domain-context.js';