rules_version = '2';

service cloud.firestore {
  match /databases/{database}/documents {
    
    // ===============================================================
    // Helper Functions
    // ===============================================================
    function isAuthenticated() {
       return request.auth != null;
    }
    
    function isOwner(userId) {
       return isAuthenticated() && request.auth.uid == userId;
    }
    
    function isDocOwner() {
       return isAuthenticated() && request.auth.uid == resource.data.authorUid;
    }
    
    function uidUnchanged() {
       return !('authorUid' in request.resource.data) ||
         request.resource.data.authorUid == request.auth.uid;
    }
    
    function uidNotModified() {
       return !('authorUid' in request.resource.data) ||
         request.resource.data.authorUid == resource.data.authorUid;
    }
    
    function hasRequiredFields(fields) {
       return request.resource.data.keys().hasAll(fields);
    }

    function isValidUrl(url) {
       return url is string &&
         (url.matches("^https://.*") || url.matches("^http://.*"));
    }
    
    function isValidNewsItem(item) {
      return item is map &&
             item.keys().hasAll(['title', 'url', 'summary']) &&
             item.title is string && item.title.size() > 0 && item.title.size() < 500 &&
             item.url is string && item.url.size() < 1000 &&
             item.summary is string && item.summary.size() > 0 && item.summary.size() < 2000;
    }
    
    function isValidNewsArray(arr) {
      return arr is list && arr.size() <= 50; // Max 50 items per section
    }
    
    function isValidSynthesis(data) {
      return hasRequiredFields(['week', 'createdAt', 'authorUid']) &&
             data.week is string && data.week.size() > 0 && data.week.size() < 20 &&
             data.createdAt is timestamp &&
             data.authorUid is string && data.authorUid.size() > 0 &&
             (!('majorAnnouncements' in data) || isValidNewsArray(data.majorAnnouncements)) &&
             (!('financialSector' in data) || isValidNewsArray(data.financialSector)) &&
             (!('otherEnterprises' in data) || isValidNewsArray(data.otherEnterprises)) &&
             (!('publicSector' in data) || isValidNewsArray(data.publicSector)) &&
             (!('generalPublic' in data) || isValidNewsArray(data.generalPublic)) &&
             (!('sections' in data) || data.sections is list);
    }

    function isValidSettings(data) {
      return hasRequiredFields(['theme', 'maxAgeDays', 'categories', 'maxItemsPerCategory']) &&
             data.theme is string && data.theme.size() > 0 && data.theme.size() < 200 &&
             data.maxAgeDays is number && data.maxAgeDays > 0 && data.maxAgeDays <= 365 &&
             data.categories is list && data.categories.size() > 0 && data.categories.size() <= 20 &&
             data.maxItemsPerCategory is number && data.maxItemsPerCategory > 0 && data.maxItemsPerCategory <= 50;
    }

    function isValidSource(data) {
      return hasRequiredFields(['title', 'url', 'authorUid', 'createdAt']) &&
             data.title is string && data.title.size() > 0 && data.title.size() < 200 &&
             data.url is string && isValidUrl(data.url) && data.url.size() < 1000 &&
             data.authorUid is string && data.authorUid.size() > 0 &&
             data.createdAt is timestamp;
    }

    match /syntheses/{synthesisId} {
      allow read: if isAuthenticated() && isDocOwner();
      allow create: if isAuthenticated() && 
                    isValidSynthesis(request.resource.data) && 
                    uidUnchanged();
      allow update: if isAuthenticated() && 
                    isDocOwner() &&
                    isValidSynthesis(request.resource.data) && 
                    uidNotModified() &&
                    request.resource.data.createdAt == resource.data.createdAt;
      allow delete: if isAuthenticated() && isDocOwner();
    }

    match /sources/{sourceId} {
      allow read: if isAuthenticated() && isDocOwner();
      allow create: if isAuthenticated() && 
                    isValidSource(request.resource.data) && 
                    uidUnchanged();
      allow update: if isAuthenticated() && 
                    isDocOwner() &&
                    isValidSource(request.resource.data) && 
                    uidNotModified() &&
                    request.resource.data.createdAt == resource.data.createdAt;
      allow delete: if isAuthenticated() && isDocOwner();
    }

    match /settings/{userId} {
      allow read: if isAuthenticated() && request.auth.uid == userId;
      allow write: if isAuthenticated() && request.auth.uid == userId &&
                   isValidSettings(request.resource.data);
    }
  }
}