'use strict';

const SMS_TEMPLATE_DEFS = [
  {
    key: 'accountCreated',
    label: 'ایجاد حساب کاربری',
    envKey: 'SMS_TEMPLATE_ACCOUNT_CREATED',
    slots: [
      { key: 'username', label: 'نام کاربری', defaultName: 'user' },
      { key: 'password', label: 'رمز عبور', defaultName: 'password' }
    ]
  },
  {
    key: 'classRegistered',
    label: 'ثبت‌نام در کلاس',
    envKey: 'SMS_TEMPLATE_CLASS_REGISTERED',
    slots: [
      { key: 'className', label: 'نام کلاس', defaultName: 'className' }
    ]
  },
  {
    key: 'classReminder',
    label: 'یادآوری کلاس',
    envKey: 'SMS_TEMPLATE_CLASS_REMINDER',
    slots: [
      { key: 'className', label: 'نام کلاس', defaultName: 'className' },
      { key: 'time', label: 'ساعت', defaultName: 'time' },
      { key: 'place', label: 'مکان', defaultName: 'place' }
    ]
  },
  {
    key: 'invoiceCreated',
    label: 'ایجاد صورتحساب',
    envKey: 'SMS_TEMPLATE_INVOICE_CREATED',
    slots: [
      { key: 'fullName', label: 'نام کارآموز', defaultName: 'FULLNAME' },
      { key: 'amount', label: 'مبلغ', defaultName: 'PAYMENT_PRICE' },
      { key: 'course', label: 'نام دوره', defaultName: 'COURSE' }
    ]
  }
];

const SMS_TEMPLATE_KEYS = SMS_TEMPLATE_DEFS.map((def) => def.key);

const envFallbackFor = (def) => {
  if (!def?.envKey) return '';
  return String(process.env[def.envKey] || '').trim();
};

const sanitizeTemplateId = (value) => {
  if (value == null) return '';
  const digits = String(value).trim();
  if (!digits) return '';
  if (!/^\d{1,20}$/.test(digits)) return null;
  return digits;
};

const sanitizeVariableName = (value) => {
  if (value == null) return '';
  const name = String(value).trim().replace(/^#+|#+$/g, '');
  if (!name) return '';
  if (!/^[A-Za-z][A-Za-z0-9_]{0,49}$/.test(name)) return null;
  return name;
};

const defaultVariableMap = (def) => {
  const map = {};
  (def.slots || []).forEach((slot) => {
    map[slot.key] = slot.defaultName;
  });
  return map;
};

const emptyTemplateEntry = (def) => ({
  templateId: '',
  variables: defaultVariableMap(def)
});

const normalizeStoredEntry = (raw) => {
  if (raw == null || raw === '') {
    return { templateId: '', variables: {} };
  }
  if (typeof raw === 'string' || typeof raw === 'number') {
    return { templateId: String(raw), variables: {} };
  }
  if (typeof raw !== 'object') {
    return { templateId: '', variables: {} };
  }

  let variables = {};
  if (raw.variables && typeof raw.variables === 'object' && !Array.isArray(raw.variables)) {
    variables = { ...raw.variables };
  } else if (Array.isArray(raw.variables)) {
    raw.variables.forEach((item) => {
      if (item?.slot) variables[item.slot] = item.name;
    });
  }

  return {
    templateId: raw.templateId != null ? String(raw.templateId) : '',
    variables
  };
};

const resolveVariableMap = (def, storedVariables = {}) => {
  const map = {};
  (def.slots || []).forEach((slot) => {
    const sanitized = sanitizeVariableName(storedVariables[slot.key]);
    map[slot.key] = sanitized || slot.defaultName;
  });
  return map;
};

const buildSmsParameters = (variableMap, valuesBySlot) => {
  return Object.entries(valuesBySlot)
    .map(([slot, value]) => {
      const name = String(variableMap?.[slot] || '').trim();
      if (!name) return null;
      return { name, value: String(value ?? '') };
    })
    .filter(Boolean);
};

module.exports = {
  SMS_TEMPLATE_DEFS,
  SMS_TEMPLATE_KEYS,
  envFallbackFor,
  sanitizeTemplateId,
  sanitizeVariableName,
  defaultVariableMap,
  emptyTemplateEntry,
  normalizeStoredEntry,
  resolveVariableMap,
  buildSmsParameters
};