const fs = require('fs');
const path = require('path');

// File Paths
const IFS_BRC_MAP_PATH = 'IFSBRC.json';
const IFS_CONTENT_PATH = 'ifs_food_v8_fr.json';
const BRC_CONTENT_PATH = 'brcGSv9.json';
const OUTPUT_PATH = 'correspondances.json';

// Utility: Clean ID (remove trailing stuff like (KO N°1) for matching)
function cleanId(id) {
    if (!id) return '';
    // Removes "(KO N°...)" and whitespace
    return id.replace(/\s*\(KO N°\d+\)/, '').trim();
}

function normalizeId(id) {
    return cleanId(id).replace(/\*$/, ''); // Remove trailing asterisks often found in IFS
}

// Main Function
function buildData() {
    console.log('Reading files...');

    let mapRaw = fs.readFileSync(IFS_BRC_MAP_PATH, 'utf8');
    // detailed fix: IFSBRC.json might be multiple arrays simply concatenated like [...] [...]
    // We try to join them into one big array.
    mapRaw = mapRaw.trim();
    // detailed logic: if it looks like `] [` or `]\r\n[` we replace with `,`
    // Regex: look for closing bracket, optional whitespace, opening bracket
    mapRaw = mapRaw.replace(/\]\s*\[/g, ',');

    const mapData = JSON.parse(mapRaw);
    const ifsData = JSON.parse(fs.readFileSync(IFS_CONTENT_PATH, 'utf8'));
    const brcData = JSON.parse(fs.readFileSync(BRC_CONTENT_PATH, 'utf8'));

    // 1. Flatten specific content into lookup maps for easy access
    const ifsLookup = {};
    const brcLookup = {};

    // Build IFS Lookup
    // Structure: Array of Chapters -> Sections -> Requirements
    ifsData.forEach(chapter => {
        chapter.sous_sections?.forEach(sub => {
            sub.exigences?.forEach(req => {
                const id = normalizeId(req.numero);
                ifsLookup[id] = {
                    id: req.numero,
                    text: req.texte,
                    chapter: chapter.titre,
                    section: sub.titre,
                    ko: req.estKO
                };
            });
        });
    });

    // Build BRC Lookup
    // Structure: part_1_info ... sections -> subsections -> clauses
    // Note: brcGSv9.json is an array of parts
    // Some sections (like 3.5) have nested subsections
    brcData.forEach(part => {
        part.sections?.forEach(section => {
            processSubsection(section.subsections, section.title);
        });
    });

    // Recursive function to handle nested subsections (like section 3.5)
    function processSubsection(subsections, sectionTitle, parentSubsectionTitle = null) {
        if (!subsections) return;
        
        subsections.forEach(sub => {
            // Get the full subsection title (include parent if exists)
            const fullSubsectionTitle = parentSubsectionTitle 
                ? `${parentSubsectionTitle} - ${sub.title}` 
                : sub.title;
            
            // Process clauses at this level
            sub.clauses?.forEach(clause => {
                brcLookup[clause.clause_id] = {
                    id: clause.clause_id,
                    text: clause.requirement,
                    section: sectionTitle,
                    subsection: fullSubsectionTitle
                };
            });
            
            // Recursively process nested subsections (like 3.5.1, 3.5.2, etc.)
            if (sub.subsections) {
                processSubsection(sub.subsections, sectionTitle, sub.title);
            }
        });
    }

    // 2. Build the Correspondence structure
    // We want a list of all IFS items, all BRC items, and the links.
    // The "mapData" (IFSBRC.json) drives the linking.

    const mappings = [];
    const usedIfsIds = new Set();
    const usedBrcIds = new Set();

    // Iterate Mapping File
    // Structure: Array of Chapters -> exigences -> ifs_ref, brc_refs (Array)
    mapData.forEach(chapter => {
        chapter.exigences?.forEach(mapping => {
            const ifsRefRaw = mapping.ifs_ref;
            const ifsIdClean = normalizeId(ifsRefRaw);

            const brcRefs = mapping.brc_refs || [];

            // Create Mapping Entry
            mappings.push({
                source_id: ifsIdClean, // Normalized for matching
                target_ids: brcRefs,
                // We can keep original ref for display if needed
                ifs_original_ref: ifsRefRaw
            });

            usedIfsIds.add(ifsIdClean);
            brcRefs.forEach(ref => usedBrcIds.add(ref));
        });
    });

    // 3. Prepare Final JSON
    // We will dump the lookups as arrays for easier iteration in frontend

    // Convert lookups to arrays
    const ifsList = Object.values(ifsLookup);
    const brcList = Object.values(brcLookup);

    const output = {
        ifs_standards: ifsList,
        brc_standards: brcList,
        mappings: mappings
    };

    const OUTPUT_JS_PATH = 'data.js';

    console.log(`IFS Items: ${ifsList.length}`);
    console.log(`BRC Items: ${brcList.length}`);
    console.log(`Mappings: ${mappings.length}`);

    const fileContent = `window.APP_DATA = ${JSON.stringify(output, null, 2)};`;

    fs.writeFileSync(OUTPUT_JS_PATH, fileContent);
    console.log(`Successfully wrote to ${OUTPUT_JS_PATH}`);
}

try {
    buildData();
} catch (e) {
    console.error("Error building data:", e);
}