/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
let DocumentManager;
const RedisManager = require("./RedisManager");
const ProjectHistoryRedisManager = require("./ProjectHistoryRedisManager");
const PersistenceManager = require("./PersistenceManager");
const DiffCodec = require("./DiffCodec");
const logger = require("logger-sharelatex");
const Metrics = require("./Metrics");
const HistoryManager = require("./HistoryManager");
const RealTimeRedisManager = require("./RealTimeRedisManager");
const Errors = require("./Errors");
const RangesManager = require("./RangesManager");
const async = require("async");

const MAX_UNFLUSHED_AGE = 300 * 1000; // 5 mins, document should be flushed to mongo this time after a change

module.exports = (DocumentManager = {
	getDoc(project_id, doc_id, _callback) {
		if (_callback == null) { _callback = function(error, lines, version, ranges, pathname, projectHistoryId, unflushedTime, alreadyLoaded) {}; }
		const timer = new Metrics.Timer("docManager.getDoc");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return RedisManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId, unflushedTime) {
			if (error != null) { return callback(error); }
			if ((lines == null) || (version == null)) {
				logger.log({project_id, doc_id}, "doc not in redis so getting from persistence API");
				return PersistenceManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId, projectHistoryType) {
					if (error != null) { return callback(error); }
					logger.log({project_id, doc_id, lines, version, pathname, projectHistoryId, projectHistoryType}, "got doc from persistence API");
					return RedisManager.putDocInMemory(project_id, doc_id, lines, version, ranges, pathname, projectHistoryId, function(error) {
						if (error != null) { return callback(error); }
						return RedisManager.setHistoryType(doc_id, projectHistoryType, function(error) {
							if (error != null) { return callback(error); }
							return callback(null, lines, version, ranges || {}, pathname, projectHistoryId, null, false);
						});
					});
				});
			} else {
				return callback(null, lines, version, ranges, pathname, projectHistoryId, unflushedTime, true);
			}
		});
	},

	getDocAndRecentOps(project_id, doc_id, fromVersion, _callback) {
		if (_callback == null) { _callback = function(error, lines, version, ops, ranges, pathname, projectHistoryId) {}; }
		const timer = new Metrics.Timer("docManager.getDocAndRecentOps");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return DocumentManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId) {
			if (error != null) { return callback(error); }
			if (fromVersion === -1) {
				return callback(null, lines, version, [], ranges, pathname, projectHistoryId);
			} else {
				return RedisManager.getPreviousDocOps(doc_id, fromVersion, version, function(error, ops) {
					if (error != null) { return callback(error); }
					return callback(null, lines, version, ops, ranges, pathname, projectHistoryId);
				});
			}
		});
	},

	setDoc(project_id, doc_id, newLines, source, user_id, undoing, _callback) {
		if (_callback == null) { _callback = function(error) {}; }
		const timer = new Metrics.Timer("docManager.setDoc");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		if ((newLines == null)) {
			return callback(new Error("No lines were provided to setDoc"));
		}

		const UpdateManager = require("./UpdateManager");
		return DocumentManager.getDoc(project_id, doc_id, function(error, oldLines, version, ranges, pathname, projectHistoryId, unflushedTime, alreadyLoaded) {
			if (error != null) { return callback(error); }

			if ((oldLines != null) && (oldLines.length > 0) && (oldLines[0].text != null)) {
				logger.log({doc_id, project_id, oldLines, newLines}, "document is JSON so not updating");
				return callback(null);
			}

			logger.log({doc_id, project_id, oldLines, newLines}, "setting a document via http");
			return DiffCodec.diffAsShareJsOp(oldLines, newLines, function(error, op) {
				if (error != null) { return callback(error); }
				if (undoing) {
					for (let o of Array.from(op || [])) {
						o.u = true;
					} // Turn on undo flag for each op for track changes
				}
				const update = {
					doc: doc_id,
					op,
					v: version,
					meta: {
						type: "external",
						source,
						user_id
					}
				};
				return UpdateManager.applyUpdate(project_id, doc_id, update, function(error) {
					if (error != null) { return callback(error); }
					// If the document was loaded already, then someone has it open
					// in a project, and the usual flushing mechanism will happen.
					// Otherwise we should remove it immediately since nothing else
					// is using it.
					if (alreadyLoaded) {
						return DocumentManager.flushDocIfLoaded(project_id, doc_id, function(error) {
							if (error != null) { return callback(error); }
							return callback(null);
						});
					} else {
						return DocumentManager.flushAndDeleteDoc(project_id, doc_id, {}, function(error) {
							// There is no harm in flushing project history if the previous
							// call failed and sometimes it is required
							HistoryManager.flushProjectChangesAsync(project_id);

							if (error != null) { return callback(error); }
							return callback(null);
						});
					}
				});
			});
		});
	},

	flushDocIfLoaded(project_id, doc_id, _callback) {
		if (_callback == null) { _callback = function(error) {}; }
		const timer = new Metrics.Timer("docManager.flushDocIfLoaded");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};
		return RedisManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId, unflushedTime, lastUpdatedAt, lastUpdatedBy) {
			if (error != null) { return callback(error); }
			if ((lines == null) || (version == null)) {
				logger.log({project_id, doc_id}, "doc is not loaded so not flushing");
				return callback(null);  // TODO: return a flag to bail out, as we go on to remove doc from memory?
			} else {
				logger.log({project_id, doc_id, version}, "flushing doc");
				return PersistenceManager.setDoc(project_id, doc_id, lines, version, ranges, lastUpdatedAt, lastUpdatedBy, function(error) {
					if (error != null) { return callback(error); }
					return RedisManager.clearUnflushedTime(doc_id, callback);
				});
			}
		});
	},

	flushAndDeleteDoc(project_id, doc_id, options, _callback) {
		const timer = new Metrics.Timer("docManager.flushAndDeleteDoc");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return DocumentManager.flushDocIfLoaded(project_id, doc_id, function(error) {
			if (error != null) {
				if (options.ignoreFlushErrors) {
					logger.warn({project_id, doc_id, err: error}, "ignoring flush error while deleting document");
				} else {
					return callback(error);
				}
			}

			// Flush in the background since it requires a http request
			HistoryManager.flushDocChangesAsync(project_id, doc_id);

			return RedisManager.removeDocFromMemory(project_id, doc_id, function(error) {
				if (error != null) { return callback(error); }
				return callback(null);
			});
		});
	},

	acceptChanges(project_id, doc_id, change_ids, _callback) {
		if (change_ids == null) { change_ids = []; }
		if (_callback == null) { _callback = function(error) {}; }
		const timer = new Metrics.Timer("docManager.acceptChanges");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return DocumentManager.getDoc(project_id, doc_id, function(error, lines, version, ranges) {
			if (error != null) { return callback(error); }
			if ((lines == null) || (version == null)) {
				return callback(new Errors.NotFoundError(`document not found: ${doc_id}`));
			}
			return RangesManager.acceptChanges(change_ids, ranges, function(error, new_ranges) {
				if (error != null) { return callback(error); }
				return RedisManager.updateDocument(project_id, doc_id, lines, version, [], new_ranges, {}, function(error) {
					if (error != null) { return callback(error); }
					return callback();
				});
			});
		});
	},

	deleteComment(project_id, doc_id, comment_id, _callback) {
		if (_callback == null) { _callback = function(error) {}; }
		const timer = new Metrics.Timer("docManager.deleteComment");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return DocumentManager.getDoc(project_id, doc_id, function(error, lines, version, ranges) {
			if (error != null) { return callback(error); }
			if ((lines == null) || (version == null)) {
				return callback(new Errors.NotFoundError(`document not found: ${doc_id}`));
			}
			return RangesManager.deleteComment(comment_id, ranges, function(error, new_ranges) {
				if (error != null) { return callback(error); }
				return RedisManager.updateDocument(project_id, doc_id, lines, version, [], new_ranges, {}, function(error) {
					if (error != null) { return callback(error); }
					return callback();
				});
			});
		});
	},

	renameDoc(project_id, doc_id, user_id, update, projectHistoryId, _callback) {
		if (_callback == null) { _callback = function(error) {}; }
		const timer = new Metrics.Timer("docManager.updateProject");
		const callback = function(...args) {
			timer.done();
			return _callback(...Array.from(args || []));
		};

		return RedisManager.renameDoc(project_id, doc_id, user_id, update, projectHistoryId, callback);
	},

	getDocAndFlushIfOld(project_id, doc_id, callback) {
		if (callback == null) { callback = function(error, doc) {}; }
		return DocumentManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId, unflushedTime, alreadyLoaded) {
			if (error != null) { return callback(error); }
			// if doc was already loaded see if it needs to be flushed
			if (alreadyLoaded && (unflushedTime != null) && ((Date.now() - unflushedTime) > MAX_UNFLUSHED_AGE)) {
				return DocumentManager.flushDocIfLoaded(project_id, doc_id, function(error) {
					if (error != null) { return callback(error); }
					return callback(null, lines, version);
				});
			} else {
				return callback(null, lines, version);
			}
		});
	},

	resyncDocContents(project_id, doc_id, callback) {
		logger.log({project_id, doc_id}, "start resyncing doc contents");
		return RedisManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId) {
			if (error != null) { return callback(error); }

			if ((lines == null) || (version == null)) {
				logger.log({project_id, doc_id}, "resyncing doc contents - not found in redis - retrieving from web");
				return PersistenceManager.getDoc(project_id, doc_id, function(error, lines, version, ranges, pathname, projectHistoryId) {
					if (error != null) {
						logger.error({project_id, doc_id, getDocError: error}, "resyncing doc contents - error retrieving from web");
						return callback(error);
					}
					return ProjectHistoryRedisManager.queueResyncDocContent(project_id, projectHistoryId, doc_id, lines, version, pathname, callback);
				});
			} else {
				logger.log({project_id, doc_id}, "resyncing doc contents - doc in redis - will queue in redis");
				return ProjectHistoryRedisManager.queueResyncDocContent(project_id, projectHistoryId, doc_id, lines, version, pathname, callback);
			}
		});
	},

	getDocWithLock(project_id, doc_id, callback) {
		if (callback == null) { callback = function(error, lines, version) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.getDoc, project_id, doc_id, callback);
	},

	getDocAndRecentOpsWithLock(project_id, doc_id, fromVersion, callback) {
		if (callback == null) { callback = function(error, lines, version, ops, ranges, pathname, projectHistoryId) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.getDocAndRecentOps, project_id, doc_id, fromVersion, callback);
	},

	getDocAndFlushIfOldWithLock(project_id, doc_id, callback) {
		if (callback == null) { callback = function(error, doc) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.getDocAndFlushIfOld, project_id, doc_id, callback);
	},

	setDocWithLock(project_id, doc_id, lines, source, user_id, undoing, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.setDoc, project_id, doc_id, lines, source, user_id, undoing, callback);
	},

	flushDocIfLoadedWithLock(project_id, doc_id, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.flushDocIfLoaded, project_id, doc_id, callback);
	},

	flushAndDeleteDocWithLock(project_id, doc_id, options, callback) {
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.flushAndDeleteDoc, project_id, doc_id, options, callback);
	},

	acceptChangesWithLock(project_id, doc_id, change_ids, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.acceptChanges, project_id, doc_id, change_ids, callback);
	},

	deleteCommentWithLock(project_id, doc_id, thread_id, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.deleteComment, project_id, doc_id, thread_id, callback);
	},

	renameDocWithLock(project_id, doc_id, user_id, update, projectHistoryId, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.renameDoc, project_id, doc_id, user_id, update, projectHistoryId, callback);
	},

	resyncDocContentsWithLock(project_id, doc_id, callback) {
		if (callback == null) { callback = function(error) {}; }
		const UpdateManager = require("./UpdateManager");
		return UpdateManager.lockUpdatesAndDo(DocumentManager.resyncDocContents, project_id, doc_id, callback);
	}
});