/* ============================================================
   GLASSGRID — CONTENT SCHEMA DEFINITIONS
   
   ⚠️  ARCHITECTURE RULE:
   All content is structured via these schemas.
   Components read schema-validated objects only.
   Raw HTML is NEVER stored or injected.
   ============================================================ */

'use strict';

const Schema = {

  // ── Post ──────────────────────────────────────────
  Post: {
    id:          { type: 'string',  required: true },
    userId:      { type: 'string',  required: true },
    mediaUrl:    { type: 'string',  required: true },   // Image URL only
    mediaType:   { type: 'enum',    values: ['image'],  default: 'image' },
    aspectRatio: { type: 'enum',    values: ['square', 'landscape', 'portrait'], default: 'square' },
    caption:     { type: 'string',  required: false, maxLength: 2200 },
    altText:     { type: 'string',  required: false, maxLength: 500 },
    tags:        { type: 'array',   items: 'string',    default: [] },
    location:    { type: 'string',  required: false, maxLength: 100 },
    likeCount:   { type: 'number',  default: 0 },
    commentCount:{ type: 'number',  default: 0 },
    saveCount:   { type: 'number',  default: 0 },
    createdAt:   { type: 'timestamp', required: true },
    isArchived:  { type: 'boolean', default: false },
    isFeatured:  { type: 'boolean', default: false },
  },

  // ── User ──────────────────────────────────────────
  User: {
    id:           { type: 'string',  required: true },
    username:     { type: 'string',  required: true, pattern: /^[a-z0-9_.]{3,30}$/ },
    displayName:  { type: 'string',  required: true, maxLength: 60 },
    avatarUrl:    { type: 'string',  required: false },
    bio:          { type: 'string',  required: false, maxLength: 160 },
    location:     { type: 'string',  required: false, maxLength: 100 },
    website:      { type: 'string',  required: false },
    followersCount:{ type: 'number', default: 0 },
    followingCount:{ type: 'number', default: 0 },
    postsCount:   { type: 'number',  default: 0 },
    isVerified:   { type: 'boolean', default: false },
    isPrivate:    { type: 'boolean', default: false },
    role:         { type: 'enum',    values: ['user', 'moderator', 'admin'], default: 'user' },
    joinedAt:     { type: 'timestamp', required: true },
    isBanned:     { type: 'boolean', default: false },
  },

  // ── Comment ───────────────────────────────────────
  Comment: {
    id:        { type: 'string',    required: true },
    postId:    { type: 'string',    required: true },
    userId:    { type: 'string',    required: true },
    text:      { type: 'string',    required: true, maxLength: 500 },
    likeCount: { type: 'number',    default: 0 },
    parentId:  { type: 'string',    required: false },  // For replies
    createdAt: { type: 'timestamp', required: true },
    isHidden:  { type: 'boolean',   default: false },
    isFlagged: { type: 'boolean',   default: false },
  },

  // ── Like ──────────────────────────────────────────
  Like: {
    id:        { type: 'string',    required: true },
    userId:    { type: 'string',    required: true },
    targetId:  { type: 'string',    required: true },  // Post or Comment ID
    targetType:{ type: 'enum',      values: ['post', 'comment'], required: true },
    createdAt: { type: 'timestamp', required: true },
  },

  // ── Story ─────────────────────────────────────────
  Story: {
    id:          { type: 'string',  required: true },
    userId:      { type: 'string',  required: true },
    mediaUrl:    { type: 'string',  required: true },
    expiresAt:   { type: 'timestamp', required: true },
    viewCount:   { type: 'number',  default: 0 },
    isHighlight: { type: 'boolean', default: false },
  },

  // ── SiteConfig ────────────────────────────────────
  SiteConfig: {
    siteName:         { type: 'string', default: 'GlassGrid' },
    tagline:          { type: 'string', default: 'Share Your World' },
    logoUrl:          { type: 'string', default: '' },
    activeTheme:      { type: 'string', default: 'midnight' },
    allowSignup:      { type: 'boolean', default: true },

    features: {
      likes:           { type: 'boolean', default: true },
      comments:        { type: 'boolean', default: true },
      stories:         { type: 'boolean', default: true },
      explore:         { type: 'boolean', default: true },
      saves:           { type: 'boolean', default: true },
      directMessages:  { type: 'boolean', default: false },
    },

    moderation: {
      requireApproval: { type: 'boolean', default: false },
      autoHideFlags:   { type: 'boolean', default: true },
      flagThreshold:   { type: 'number',  default: 3 },
      allowedDomains:  { type: 'array',   items: 'string', default: [] },
    },

    limits: {
      maxPostsPerDay:  { type: 'number', default: 20 },
      maxCaptionLength:{ type: 'number', default: 2200 },
      maxCommentLength:{ type: 'number', default: 500 },
      maxBioLength:    { type: 'number', default: 160 },
    },
  },

};

/**
 * Validate a data object against a schema definition.
 * Returns { valid: bool, errors: string[] }
 */
function validate(schemaName, data) {
  const schema = Schema[schemaName];
  if (!schema) return { valid: false, errors: [`Unknown schema: ${schemaName}`] };

  const errors = [];

  for (const [key, rules] of Object.entries(schema)) {
    if (typeof rules !== 'object' || Array.isArray(rules)) continue;

    const value = data[key];
    const isDefined = value !== undefined && value !== null;

    if (rules.required && !isDefined) {
      errors.push(`"${key}" is required`);
      continue;
    }

    if (!isDefined) continue;

    if (rules.type === 'string' && typeof value !== 'string')
      errors.push(`"${key}" must be a string`);

    if (rules.maxLength && typeof value === 'string' && value.length > rules.maxLength)
      errors.push(`"${key}" exceeds max length of ${rules.maxLength}`);

    if (rules.type === 'enum' && !rules.values.includes(value))
      errors.push(`"${key}" must be one of: ${rules.values.join(', ')}`);

    if (rules.type === 'number' && typeof value !== 'number')
      errors.push(`"${key}" must be a number`);

    if (rules.type === 'boolean' && typeof value !== 'boolean')
      errors.push(`"${key}" must be a boolean`);

    if (rules.pattern && typeof value === 'string' && !rules.pattern.test(value))
      errors.push(`"${key}" does not match required pattern`);
  }

  return { valid: errors.length === 0, errors };
}

/**
 * Apply defaults from schema to a data object.
 */
function applyDefaults(schemaName, data = {}) {
  const schema = Schema[schemaName];
  if (!schema) return data;

  const result = { ...data };
  for (const [key, rules] of Object.entries(schema)) {
    if (typeof rules !== 'object' || Array.isArray(rules)) continue;
    if (result[key] === undefined && rules.default !== undefined) {
      result[key] = typeof rules.default === 'object'
        ? JSON.parse(JSON.stringify(rules.default))
        : rules.default;
    }
  }
  return result;
}

export { Schema, validate, applyDefaults };