#!/usr/bin/env node
"use strict";

const fs = require("node:fs");
const path = require("node:path");

function printUsage() {
    console.log(`
Usage:
  node tools/ggs-dist-cli.js extract [--ggs-root <path>] [--out <file>]
  node tools/ggs-dist-cli.js apply --profile <file> [--out <file>]

Commands:
  extract   Build a full firearm/attachment/magazine spawn catalog from GaelGunStore.
  apply     Convert a webapp profile JSON into Lua used by the B42 mod patcher.
`.trim());
}

function parseArgs(argv) {
    const args = { _: [] };
    for (let i = 0; i < argv.length; i += 1) {
        const token = argv[i];
        if (token.startsWith("--")) {
            const key = token.slice(2);
            const next = argv[i + 1];
            if (!next || next.startsWith("--")) {
                args[key] = true;
            } else {
                args[key] = next;
                i += 1;
            }
        } else {
            args._.push(token);
        }
    }
    return args;
}

function ensureDir(filePath) {
    fs.mkdirSync(path.dirname(filePath), { recursive: true });
}

function readText(filePath) {
    return fs.readFileSync(filePath, "utf8");
}

function writeText(filePath, content) {
    ensureDir(filePath);
    fs.writeFileSync(filePath, content, "utf8");
}

function walkFiles(rootDir, predicate, out) {
    const entries = fs.readdirSync(rootDir, { withFileTypes: true });
    for (const entry of entries) {
        const fullPath = path.join(rootDir, entry.name);
        if (entry.isDirectory()) {
            walkFiles(fullPath, predicate, out);
        } else if (predicate(fullPath)) {
            out.push(fullPath);
        }
    }
}

function collectItemTypesFromScripts(rootDir) {
    const files = [];
    walkFiles(rootDir, (fullPath) => fullPath.toLowerCase().endsWith(".txt"), files);
    const itemSet = new Set();
    const itemPattern = /^\s*item\s+([A-Za-z0-9_]+)/gm;
    for (const filePath of files) {
        const text = readText(filePath);
        let match = itemPattern.exec(text);
        while (match) {
            itemSet.add(`Base.${match[1]}`);
            match = itemPattern.exec(text);
        }
    }
    return Array.from(itemSet).sort();
}

function parseLootEntries(lootLuaPath) {
    const lootLua = readText(lootLuaPath);
    const pattern =
        /\{\s*list\s*=\s*"([^"]+)"\s*,\s*item\s*=\s*"([^"]+)"\s*,\s*weight\s*=\s*([0-9]+(?:\.[0-9]+)?)\s*,\s*sv\s*=\s*"([^"]+)"\s*\}/g;
    const entries = [];
    let match = pattern.exec(lootLua);
    while (match) {
        entries.push({
            list: match[1],
            item: match[2],
            weight: Number.parseFloat(match[3]),
            sv: match[4],
        });
        match = pattern.exec(lootLua);
    }
    return entries;
}

function aggregatePlacements(entries) {
    const placementMap = new Map();
    for (const entry of entries) {
        const previous = placementMap.get(entry.list) || 0;
        placementMap.set(entry.list, previous + entry.weight);
    }
    return Array.from(placementMap.entries())
        .map(([list, weight]) => ({ list, weight: Number(weight.toFixed(6)) }))
        .sort((a, b) => a.list.localeCompare(b.list));
}

function normalizeItemType(item) {
    if (typeof item !== "string") {
        return null;
    }
    const trimmed = item.trim();
    if (!trimmed) {
        return null;
    }
    return trimmed.includes(".") ? trimmed : `Base.${trimmed}`;
}

function isMagazineType(itemType) {
    const s = String(itemType || "").toLowerCase();
    if (!s) {
        return false;
    }
    if (s.startsWith("base.clip_")) {
        return true;
    }
    if (s.includes("magazine")) {
        return true;
    }
    if (s.includes("drum")) {
        return true;
    }
    if (s.includes("clip")) {
        return true;
    }
    return false;
}

function buildCatalog(ggsRoot) {
    const cwd = process.cwd();
    const firearmScriptsDir = path.join(ggsRoot, "media", "scripts", "Firearms");
    const attachmentScriptsDir = path.join(ggsRoot, "media", "scripts", "GunPartItem");
    const lootLuaPath = path.join(ggsRoot, "media", "lua", "server", "item", "loot.lua");

    if (!fs.existsSync(firearmScriptsDir)) {
        throw new Error(`Missing firearms scripts dir: ${firearmScriptsDir}`);
    }
    if (!fs.existsSync(attachmentScriptsDir)) {
        throw new Error(`Missing attachments scripts dir: ${attachmentScriptsDir}`);
    }
    if (!fs.existsSync(lootLuaPath)) {
        throw new Error(`Missing loot file: ${lootLuaPath}`);
    }

    const firearms = collectItemTypesFromScripts(firearmScriptsDir);
    const attachments = collectItemTypesFromScripts(attachmentScriptsDir);
    const firearmSet = new Set(firearms);
    const attachmentSet = new Set(attachments);
    const magazineSet = new Set();

    const lootEntries = parseLootEntries(lootLuaPath);
    const perItemLoot = new Map();
    const allLists = new Set();
    const allItems = new Set([...firearms, ...attachments]);

    for (const entry of lootEntries) {
        const normalized = normalizeItemType(entry.item);
        if (!normalized) {
            continue;
        }
        if (isMagazineType(normalized)) {
            magazineSet.add(normalized);
            allItems.add(normalized);
        }
    }

    for (const entry of lootEntries) {
        const normalized = normalizeItemType(entry.item);
        if (!normalized) {
            continue;
        }
        if (!allItems.has(normalized)) {
            continue;
        }
        allLists.add(entry.list);

        const existing = perItemLoot.get(normalized) || [];
        existing.push({
            list: entry.list,
            weight: entry.weight,
            sv: entry.sv,
        });
        perItemLoot.set(normalized, existing);
    }

    const items = Array.from(allItems)
        .sort()
        .map((itemType) => {
            const placements = perItemLoot.get(itemType) || [];
            const aggregatedPlacements = aggregatePlacements(placements);
            const svKeys = Array.from(new Set(placements.map((p) => p.sv))).sort();
            let category = "unknown";
            if (firearmSet.has(itemType)) {
                category = "firearm";
            } else if (magazineSet.has(itemType)) {
                category = "magazine";
            } else if (attachmentSet.has(itemType)) {
                category = "attachment";
            }

            return {
                item: itemType,
                shortId: itemType.replace(/^Base\./, ""),
                category,
                defaultEnabled: false,
                spawnControlKeys: svKeys,
                placements,
                aggregatedPlacements,
            };
        });

    return {
        formatVersion: 1,
        generatedAt: new Date().toISOString(),
        source: {
            ggsRoot: path.relative(cwd, path.resolve(ggsRoot)) || ".",
            lootLuaPath: path.relative(cwd, path.resolve(lootLuaPath)),
            firearmScriptsDir: path.relative(cwd, path.resolve(firearmScriptsDir)),
            attachmentScriptsDir: path.relative(cwd, path.resolve(attachmentScriptsDir)),
        },
        notes: {
            spawnRateFormula: "effectiveWeight = baseWeight * lootAmountMultiplier * SandboxVars[sv]",
            lootAmountMultiplierLookup: [0, 0.25, 0.5, 1, 2, 4],
        },
        counts: {
            firearms: firearms.length,
            attachments: attachments.length,
            magazines: magazineSet.size,
            totalItems: items.length,
            placementRows: lootEntries.length,
            distributionLists: allLists.size,
        },
        lists: Array.from(allLists).sort(),
        items,
    };
}

function formatLuaString(value) {
    return `"${String(value).replace(/\\/g, "\\\\").replace(/"/g, '\\"')}"`;
}

function toLuaProfile(profileJson) {
    if (!profileJson || !Array.isArray(profileJson.entries)) {
        throw new Error("Profile JSON must contain an entries array.");
    }

    const itemsMap = new Map();
    for (const rawEntry of profileJson.entries) {
        const itemType = normalizeItemType(rawEntry && rawEntry.item);
        if (!itemType) {
            continue;
        }

        const enabled = rawEntry.enabled !== false;
        const placements = {};

        if (Array.isArray(rawEntry.placements)) {
            for (const placement of rawEntry.placements) {
                const listName =
                    placement && typeof placement.list === "string" ? placement.list.trim() : "";
                const weight = Number.parseFloat(placement && placement.weight);
                if (!listName || !Number.isFinite(weight) || weight <= 0) {
                    continue;
                }
                placements[listName] = Number(weight.toFixed(6));
            }
        } else if (rawEntry && typeof rawEntry.placements === "object" && rawEntry.placements) {
            for (const [listName, rawWeight] of Object.entries(rawEntry.placements)) {
                const cleanList = listName.trim();
                const weight = Number.parseFloat(rawWeight);
                if (!cleanList || !Number.isFinite(weight) || weight <= 0) {
                    continue;
                }
                placements[cleanList] = Number(weight.toFixed(6));
            }
        }

        itemsMap.set(itemType, {
            enabled,
            placements,
        });
    }

    const itemTypes = Array.from(itemsMap.keys()).sort();
    const lines = [];
    lines.push("-- Auto-generated by tools/ggs-dist-cli.js apply");
    lines.push(`-- Generated at: ${new Date().toISOString()}`);
    lines.push("return {");
    lines.push("    items = {");

    for (const itemType of itemTypes) {
        const config = itemsMap.get(itemType);
        lines.push(`        [${formatLuaString(itemType)}] = {`);
        lines.push(`            enabled = ${config.enabled ? "true" : "false"},`);
        lines.push("            placements = {");

        const listNames = Object.keys(config.placements).sort();
        for (const listName of listNames) {
            const weight = config.placements[listName];
            lines.push(`                [${formatLuaString(listName)}] = ${weight},`);
        }

        lines.push("            },");
        lines.push("        },");
    }

    lines.push("    },");
    lines.push("}");
    lines.push("");
    return lines.join("\n");
}

function commandExtract(args) {
    const cwd = process.cwd();
    const ggsRoot = path.resolve(cwd, args["ggs-root"] || path.join("source", "GaelGunStore", "42"));
    const outPath = path.resolve(cwd, args.out || path.join("data", "ggs-spawn-catalog.json"));

    const catalog = buildCatalog(ggsRoot);
    writeText(outPath, `${JSON.stringify(catalog, null, 2)}\n`);

    console.log(`Extracted catalog: ${outPath}`);
    console.log(
        `Items=${catalog.counts.totalItems}, Firearms=${catalog.counts.firearms}, Attachments=${catalog.counts.attachments}, Magazines=${catalog.counts.magazines}, Lists=${catalog.counts.distributionLists}`
    );
}

function commandApply(args) {
    const cwd = process.cwd();
    const profilePath = args.profile ? path.resolve(cwd, args.profile) : null;
    const outPath = path.resolve(
        cwd,
        args.out || path.join("common", "media", "lua", "shared", "OFSpawnProfile.lua")
    );

    if (!profilePath) {
        throw new Error("Missing required --profile <file> argument.");
    }
    if (!fs.existsSync(profilePath)) {
        throw new Error(`Profile file not found: ${profilePath}`);
    }

    const profileJson = JSON.parse(readText(profilePath));
    const luaProfile = toLuaProfile(profileJson);
    writeText(outPath, luaProfile);

    console.log(`Applied profile to Lua: ${outPath}`);
}

function main() {
    const args = parseArgs(process.argv.slice(2));
    const command = args._[0];

    if (!command || command === "help" || args.help) {
        printUsage();
        return;
    }

    if (command === "extract") {
        commandExtract(args);
        return;
    }

    if (command === "apply") {
        commandApply(args);
        return;
    }

    throw new Error(`Unknown command: ${command}`);
}

try {
    main();
} catch (error) {
    console.error(`[ggs-dist-cli] ${error.message}`);
    process.exitCode = 1;
}