const BUILTIN_EPG_SOURCES = Object.freeze([
    Object.freeze({ builtinKey: 'epgpw-fr', type: 'epg', name: 'EPG.PW France', url: 'https://epg.pw/xmltv/epg_FR.xml.gz', provider: 'EPG.PW', language: 'fr', country: 'FR', priority: 100 }),
    Object.freeze({ builtinKey: 'epgpw-us', type: 'epg', name: 'EPG.PW United States', url: 'https://epg.pw/xmltv/epg_US.xml.gz', provider: 'EPG.PW', language: 'en', country: 'US', priority: 90 })
]);

function protectedFields(source) {
    return source?.builtinKey ? { readonly: true, removable: false } : { readonly: false, removable: true };
}

function ensureBuiltinSources(database) {
    database.sources ||= [];
    for (const definition of BUILTIN_EPG_SOURCES) {
        const existing = database.sources.find(source => source.builtinKey === definition.builtinKey);
        if (existing) Object.assign(existing, definition, protectedFields(definition));
        else database.sources.push({ id: database.nextId++, ...definition, ...protectedFields(definition), enabled: false, created_at: new Date().toISOString(), updated_at: new Date().toISOString() });
    }
    return database;
}

module.exports = { BUILTIN_EPG_SOURCES, ensureBuiltinSources, protectedFields };