"use strict";

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

function safeReadJson(filePath, logFn) {
    try {
        const txt = fs.readFileSync(filePath, "utf8");
        if (!txt || txt.trim().length === 0) return null;
        return JSON.parse(txt);
    } catch (e) {
        if (logFn) logFn("safeReadJson failed", filePath, e && e.message ? e.message : e);
        return null;
    }
}

function isDirectory(p) {
    try {
        return fs.statSync(p).isDirectory();
    } catch (e) {
        return false;
    }
}

function scanSkillEntry(skillDir, folderName, opts) {
    opts = opts || {};
    const menuJsonPath = path.join(skillDir, "menuEntry.json");
    const menuJson = safeReadJson(menuJsonPath, opts.log);

    if (!menuJson) return null;
    if (menuJson.hidden === true) return null;

    const entry = {
        id: folderName,
        type: menuJson.type || "skill",
        title: menuJson.title || menuJson.label || folderName,
        icon: menuJson.icon || menuJson.iconSrc || (opts.defaultIcon || "resources/icons/settings.png"),
        color: menuJson.color || menuJson.colors || (opts.defaultColor || "default"),
        description: menuJson.description || "",
        path: skillDir,
        order: typeof menuJson.order === "number" ? menuJson.order : (typeof opts.defaultOrder === "number" ? opts.defaultOrder : 100),
        skillId: menuJson.skillId || folderName,
        submenuTitle: menuJson.submenuTitle || menuJson.title || folderName
    };

    if (entry.type === "submenu") {
        entry.children = scanSubmenuChildren(skillDir, opts);
    }

    // Legacy support
    if (menuJson.isSubmenu === true && entry.type !== "submenu") {
        entry.type = "submenu";
        entry.children = scanSubmenuChildren(skillDir, opts);
    }

    return entry;
}

function scanSubmenuChildren(submenuDir, opts) {
    const children = [];
    let items;
    try {
        items = fs.readdirSync(submenuDir);
    } catch (e) {
        return children;
    }

    items.forEach(function (name) {
        if (!name || name.charAt(0) === ".") return;
        if (name === "@be" || name === "node_modules") return;

        const childPath = path.join(submenuDir, name);
        if (!isDirectory(childPath)) return;

        const entry = scanSkillEntry(childPath, name, opts);
        if (entry && entry.type === "skill") {
            children.push(entry);
        }
    });

    children.sort(function (a, b) {
        if (a.order !== b.order) return a.order - b.order;
        return String(a.title || "").localeCompare(String(b.title || ""));
    });

    return children;
}

function scanAllMenuEntries(skillsRoot, opts) {
    opts = opts || {};
    const entries = [];

    if (!skillsRoot || !fs.existsSync(skillsRoot)) {
        if (opts.log) opts.log("skills root missing", skillsRoot);
        return entries;
    }

    let children;
    try {
        children = fs.readdirSync(skillsRoot);
    } catch (e) {
        if (opts.log) opts.log("failed to read skills root", skillsRoot, e && e.message ? e.message : e);
        return entries;
    }

    children.forEach(function (name) {
        if (!name || name.charAt(0) === ".") return;
        if (name === "@be" || name === "node_modules") return;

        const skillDir = path.join(skillsRoot, name);
        if (!isDirectory(skillDir)) return;

        const entry = scanSkillEntry(skillDir, name, opts);
        if (entry) entries.push(entry);
    });

    entries.sort(function (a, b) {
        if (a.order !== b.order) return a.order - b.order;
        return String(a.title || "").localeCompare(String(b.title || ""));
    });

    return entries;
}

function collectDynamicSkillIds(entries) {
    const ids = new Set();

    (entries || []).forEach(function (e) {
        if (!e) return;
        if (e.type === "skill") {
            if (e.skillId) ids.add(e.skillId);
            if (e.id) ids.add(e.id);
        }
        if (e.type === "submenu" && e.children && e.children.length) {
            e.children.forEach(function (c) {
                if (!c) return;
                if (c.skillId) ids.add(c.skillId);
                if (c.id) ids.add(c.id);
            });
        }
    });

    return ids;
}

module.exports = {
    scanAllMenuEntries: scanAllMenuEntries,
    scanSubmenuChildren: scanSubmenuChildren,
    collectDynamicSkillIds: collectDynamicSkillIds
};