rules_version = '2';

service cloud.firestore {
  	match /databases/{database}/documents {
		function isSignedIn() {
			return request.auth != null;
		}

		function isAdmin() {
			return request.auth.token.admin == true;
		}

		function getGroupRole(groupId) {
			return get(/databases/$(database)/documents/users/$(request.auth.uid)/groups/$(groupId)).data.role;
		}
		
		function isSetOwner(setId) {
			return get(/databases/$(database)/documents/sets/$(setId)).data.owner == request.auth.uid;
		}
		
		function isSetOwnerAndHasNoGroups(setId) {
			let data = get(/databases/$(database)/documents/sets/$(setId)).data;
			return data.owner == request.auth.uid && (data == null || data.groups == null || data.groups == []);
		}

		function isSetOwnerOrIsPublic(setId) {
			let data = get(/databases/$(database)/documents/sets/$(setId)).data;
			return data.public || data.owner == request.auth.uid;
		}

		function verifyCreateFields(fields) {
			return request.resource.data.keys().hasAll(fields[0]) && request.resource.data.keys().hasOnly(fields[1]);
		}

		function verifyUpdateFields(fields) {
			let affectedKeys = request.resource.data.diff(resource.data).affectedKeys();
			return affectedKeys.hasAll([]) && affectedKeys.hasOnly(fields[1]);
		}

		function getRequestField(field, default_value) {
			return request.resource.data.get(field, default_value);
		}

		function verifyBoolType(field) {
			return getRequestField(field, true) is bool;
		}

		function verifyStringType(field) {
			return getRequestField(field, "") is string;
		}

		function verifyEmptyArrayType(field) {
			return getRequestField(field, []) == [];
		}

		match /users/{userId} {
			function isSignedInUser() {
				return request.auth.uid == userId;
			}
			
			function verifyThemeValue() {
				let requestField = getRequestField("theme", "default");
				let themes = ["default", "red", "maroon", "green", "light-blue", "pink", "yellow", "orange"];
				return requestField in themes;
			}

			function verifyFieldTypes() {
				return verifyBoolType("sound") &&
					verifyBoolType("coloredEdges") &&
					verifyThemeValue();
			}

			function getPossibleFields() {
				let requiredFields = ["sound", "theme", "coloredEdges"];
				let optionalFields = [];
				let allFields = requiredFields.concat(optionalFields);
				return [requiredFields, allFields];
			}

			allow read: if isSignedIn() && isSignedInUser(); // is current user's data
			allow update: if isSignedIn() && isSignedInUser() && verifyUpdateFields(getPossibleFields()) && verifyFieldTypes();

			match /groups/{groupId} {
				function verifyGroupFieldTypes() {
					return getRequestField("role", "member") == "member" ||
						getRequestField("role", "contributor") == "contributor" ||
						getRequestField("role", "owner") == "owner";
				}

				function getPossibleGroupFields() {
					let requiredFields = ["role"];
					let optionalFields = [];
					let allFields = requiredFields.concat(optionalFields);
					return [requiredFields, allFields];
				}

				allow read, delete: if isSignedIn() && (isSignedInUser() || getGroupRole(groupId) == "owner" || isAdmin()); // is current user's data or is owner of group or is admin
				allow create: if isSignedIn() && isSignedInUser() && (getRequestField("role", "") == "member" || (isAdmin() && verifyGroupFieldTypes())) && verifyCreateFields(getPossibleGroupFields());
				allow update: if isSignedIn() &&
					(getGroupRole(groupId) == "owner" || isAdmin()) &&
					verifyGroupFieldTypes() &&
					!(isSignedInUser()) && verifyUpdateFields(getPossibleGroupFields());
				allow update: if isSignedIn() &&
					isAdmin() &&
					isSignedInUser() &&
					getRequestField("role", "") == "owner";
			}
		}

		match /groups/{groupId} {
			function verifyFieldTypes() {
				return verifyStringType("display_name");
			}

			function getPossibleFields() {
				let nonStaticFields = ["display_name"];
				let staticFields = ["join_code", "sets", "users"];

				let allFields = staticFields.concat(nonStaticFields);
				return [nonStaticFields, allFields];
			}

			function getPossibleUpdateFields() {
				let fields = getPossibleFields();
				return [[], fields[0]];
			}

			allow read: if isSignedIn() && (getGroupRole(groupId) != null || isAdmin());
			allow update: if isSignedIn() && (getGroupRole(groupId) == "owner" || isAdmin()) && verifyUpdateFields(getPossibleUpdateFields()) && verifyFieldTypes();
			allow delete: if isSignedIn() && (getGroupRole(groupId) == "owner" || isAdmin());
		}


		match /sets/{setId} {
			function verifyPublicField() {
				return ((resource == null || resource.data == null  || resource.data.groups == [] || resource.data.group == null) && verifyBoolType("public")) ||
					(resource.data.groups != [] && resource.data.groups is list && getRequestField("public", true) == true);
			}

			function verifyFieldTypes() {
				return verifyPublicField() &&
					verifyStringType("title") &&
					verifyStringType("owner") &&
					verifyEmptyArrayType("groups");
			}

			function getPossibleFields() {
				let nonStaticFields = ["public", "title"];
				let staticFields = ["owner", "groups"];

				let allFields = staticFields.concat(nonStaticFields);
				return [nonStaticFields, allFields];
			}

			function getPossibleCreateFields() {
				let fields = getPossibleFields();
				return [fields[1], fields[1]];
			}

			function getPossibleUpdateFields() {
				let fields = getPossibleFields();
				return [[], fields[0]];
			}

			allow read: if isSignedIn() && (request.auth.uid == resource.data.owner || resource.data.public == true);
			allow create: if isSignedIn() && request.auth.uid == request.resource.data.owner && verifyCreateFields(getPossibleCreateFields()) && verifyFieldTypes();
			allow update: if isSignedIn() && request.auth.uid == resource.data.owner && verifyUpdateFields(getPossibleUpdateFields()) && verifyFieldTypes();
			allow delete: if isSignedIn() && request.auth.uid == resource.data.owner && (resource == null || resource.data == null  || resource.data.groups == []);

			match /vocab/{vocabId} {
				function verifyVocabFieldTypes() {
					return verifyStringType("term") &&
						verifyStringType("definition") &&
						verifyBoolType("sound");
				}
				
				function getPossibleFields() {
					let nonStaticFields = ["term", "definition"];
					let staticFields = ["sound"];

					let allFields = staticFields.concat(nonStaticFields);
					return [nonStaticFields, allFields];
				}

				function getPossibleCreateFields() {
					let fields = getPossibleFields();
					return [fields[1], fields[1]];
				}

				function getPossibleUpdateFields() {
					let fields = getPossibleFields();
					return [[], fields[0]];
				}

				allow read: if isSignedIn() && isSetOwnerOrIsPublic(setId);
				allow create: if isSignedIn() && isSetOwner(setId) && verifyCreateFields(getPossibleCreateFields()) && verifyVocabFieldTypes();
				allow update: if isSignedIn() && isSetOwner(setId) && verifyUpdateFields(getPossibleUpdateFields()) && verifyVocabFieldTypes();
				allow delete: if isSignedIn() && isSetOwnerAndHasNoGroups(setId);
			}
		}

		match /progress/{progressId} {
			function isProgressUser() {
				return get(/databases/$(database)/documents/progress/$(progressId)).data.uid == request.auth.uid;
			}

			function isLanguageSwitched() {
				return get(/databases/$(database)/documents/progress/$(progressId)).data.switch_language;
			}
			
			function isNotComplete() {
				return get(/databases/$(database)/documents/progress/$(progressId)).data.progress < get(/databases/$(database)/documents/progress/$(progressId)).data.questions.size();
			}

			allow read: if isSignedIn() && resource.data.uid == request.auth.uid;
			allow delete: if isSignedIn() && resource.data.uid == request.auth.uid && isNotComplete();

			match /terms/{vocabId} {
				allow read: if isSignedIn() && isProgressUser() && (!(isLanguageSwitched()) || !(isNotComplete()));
			}

			match /definitions/{vocabId} {
				allow read: if isSignedIn() && isProgressUser() && (isLanguageSwitched() || !(isNotComplete()));
			}
		}

		match /join_codes/{joinCode} {
			allow get: if isSignedIn();
		}

		match /completed_progress/{setIds} {
			allow get: if isSignedIn();
		}

		match /incorrect_answers/{incorrectAnswerId} {
			allow read: if isSignedIn();
		}
  	}
}