import debounce from 'lodash/debounce';

import { Autowired, Injectable } from '@opensumi/di';
import {
  CommandService,
  Disposable,
  EDITOR_COMMANDS,
  Emitter,
  IEventBus,
  ILogger,
  IRange,
  IReporterService,
  PreferenceService,
  REPORT_NAME,
  SaveTaskErrorCause,
  SaveTaskResponseState,
  Throttler,
  URI,
  formatLocalize,
  isThenable,
  isUndefinedOrNull,
  localize,
} from '@opensumi/ide-core-browser';
import { IHashCalculateService } from '@opensumi/ide-core-common/lib/hash-calculate/hash-calculate';
import { URI as MonacoURI, monaco } from '@opensumi/ide-monaco/lib/browser/monaco-api';
import { EOL, EndOfLineSequence, ITextModel } from '@opensumi/ide-monaco/lib/browser/monaco-api/types';
import { IMessageService } from '@opensumi/ide-overlay';
import {
  EditOperation,
  ISingleEditOperation,
} from '@opensumi/monaco-editor-core/esm/vs/editor/common/core/editOperation';
import { Range } from '@opensumi/monaco-editor-core/esm/vs/editor/common/core/range';
import {
  DefaultEndOfLine,
  EndOfLinePreference,
  ITextBuffer,
} from '@opensumi/monaco-editor-core/esm/vs/editor/common/model';
import { createTextBuffer } from '@opensumi/monaco-editor-core/esm/vs/editor/common/model/textModel';

import {
  IDocCache,
  IDocCacheValue,
  IDocPersistentCacheProvider,
  IEditorDocumentModelContentChange,
  SaveReason,
  isDocContentCache,
} from '../../common';
import { AUTO_SAVE_MODE, IEditorDocumentModel } from '../../common/editor';
import { EditorPreferences } from '../preference/schema';
import { createEditorPreferenceProxy } from '../preference/util';
import { CompareResult, ICompareService } from '../types';

import { EditorDocumentError } from './editor-document-error';
import { IEditorDocumentModelServiceImpl, SaveTask } from './save-task';
import {
  EditorDocumentModelContentChangedEvent,
  EditorDocumentModelOptionChangedEvent,
  EditorDocumentModelRemovalEvent,
  EditorDocumentModelSavedEvent,
  EditorDocumentModelWillSaveEvent,
  IDocModelUpdateOptions,
  IEditorDocumentModelContentRegistry,
  IEditorDocumentModelService,
  ORIGINAL_DOC_SCHEME,
} from './types';

export interface EditorDocumentModelConstructionOptions {
  eol?: EOL;
  encoding?: string;
  languageId?: string;
  readonly?: boolean;
  savable?: boolean;
  alwaysDirty?: boolean;
  closeAutoSave?: boolean;
  disposeEvenDirty?: boolean;
}

export interface IDirtyChange {
  fromVersionId: number;
  toVersionId: number;
  changes: IEditorDocumentModelContentChange[];
}

@Injectable({ multiple: true })
export class EditorDocumentModel extends Disposable implements IEditorDocumentModel {
  @Autowired(IEditorDocumentModelContentRegistry)
  contentRegistry: IEditorDocumentModelContentRegistry;

  @Autowired(IEditorDocumentModelService)
  service: IEditorDocumentModelServiceImpl;

  @Autowired(ICompareService)
  compareService: ICompareService;

  @Autowired(IDocPersistentCacheProvider)
  cacheProvider: IDocPersistentCacheProvider;

  editorPreferences: EditorPreferences;

  @Autowired(IMessageService)
  messageService: IMessageService;

  @Autowired(IEventBus)
  eventBus: IEventBus;

  @Autowired(ILogger)
  logger: ILogger;

  @Autowired(CommandService)
  private commandService: CommandService;

  @Autowired(IReporterService)
  private reporter: IReporterService;

  @Autowired(PreferenceService)
  preferences: PreferenceService;

  @Autowired(IHashCalculateService)
  private readonly hashCalculateService: IHashCalculateService;

  private saveQueue = new Throttler();

  private monacoModel: ITextModel;

  public _encoding = 'utf8';

  public readonly readonly: boolean = false;

  public readonly savable: boolean = false;

  public readonly alwaysDirty: boolean = false;

  public readonly closeAutoSave: boolean = false;

  public readonly disposeEvenDirty: boolean = false;

  private _originalEncoding: string = this._encoding;

  private _persistVersionId = 0;

  private _baseContent = '';

  private _baseContentMd5: string | null;

  private savingTasks: SaveTask[] = [];

  private dirtyChanges: IDirtyChange[] = [];

  private _previousVersionId: number;

  private _tryAutoSaveAfterDelay: (() => any) | undefined;

  private _isInitOption = true;

  private readonly _onDidChangeEncoding = new Emitter<void>();
  readonly onDidChangeEncoding = this._onDidChangeEncoding.event;

  constructor(public readonly uri: URI, content: string, options: EditorDocumentModelConstructionOptions = {}) {
    super();

    this.onDispose(() => {
      this.eventBus.fire(new EditorDocumentModelRemovalEvent(this.uri));
    });
    if (options.encoding) {
      this._encoding = options.encoding;
    }
    this.readonly = !!options.readonly;
    this.savable = !!options.savable;
    this.alwaysDirty = !!options.alwaysDirty;
    this.disposeEvenDirty = !!options.disposeEvenDirty;
    this.closeAutoSave = !!options.closeAutoSave;

    this.monacoModel = monaco.editor.createModel(content, options.languageId, MonacoURI.parse(uri.toString()));
    this.editorPreferences = createEditorPreferenceProxy(this.preferences, this.uri.toString(), this.languageId);
    this.updateOptions({});
    if (options.eol) {
      this.eol = options.eol;
    }
    this._originalEncoding = this._encoding;
    this._previousVersionId = this.monacoModel.getVersionId();
    this._persistVersionId = this.monacoModel.getAlternativeVersionId();
    this.baseContent = content;

    this._isInitOption = false;
    this.listenTo(this.monacoModel);
    this.readCacheToApply();

    this.addDispose(this._onDidChangeEncoding);

    this.addDispose(
      this.monacoModel.onDidChangeLanguage((e) => {
        this.eventBus.fire(
          new EditorDocumentModelOptionChangedEvent({
            uri: this.uri,
            languageId: e.newLanguage,
          }),
        );
      }),
    );
  }

  updateOptions(options: IDocModelUpdateOptions) {
    const finalOptions = {
      tabSize: this.editorPreferences['editor.tabSize'] || 1,
      insertSpaces: this.editorPreferences['editor.insertSpaces'],
      detectIndentation: this.editorPreferences['editor.detectIndentation'],
      ...options,
    } as IDocModelUpdateOptions;
    if (finalOptions.detectIndentation) {
      this.monacoModel.detectIndentation(finalOptions.insertSpaces!, finalOptions.tabSize!);
    } else {
      this.monacoModel.updateOptions(finalOptions);
    }
  }

  private listenTo(monacoModel: ITextModel) {
    this.addDispose(
      monacoModel.onDidChangeContent((e) => {
        if (e.changes && e.changes.length > 0) {
          this.dirtyChanges.push({
            fromVersionId: this._previousVersionId,
            toVersionId: e.versionId,
            changes: e.changes,
          });
        }
        this._previousVersionId = e.versionId;
        this.notifyChangeEvent(e.changes, e.isRedoing, e.isUndoing);
      }),
    );

    this.addDispose(monacoModel);
  }

  private readCacheToApply() {
    if (!this.cacheProvider.hasCache(this.uri)) {
      return;
    }

    const maybePromiseCache = this.cacheProvider.getCache(this.uri, this.encoding);
    if (maybePromiseCache) {
      if (isThenable(maybePromiseCache)) {
        maybePromiseCache
          .then((cache) => {
            if (cache) {
              this.applyCache(cache);
            }
          })
          .catch((err) => {
            this.logger.error(`${EditorDocumentError.READ_CACHE_ERROR} ${err && err.message}`);
          });
      } else {
        this.applyCache(maybePromiseCache as IDocCache);
      }
    }
  }

  private applyCache(cache: IDocCache) {
    if (this.dirty) {
      this.logger.error(EditorDocumentError.APPLY_CACHE_TO_DIRTY_DOCUMENT);
      return;
    }

    if (this.baseContentMd5 !== cache.startMD5) {
      this.logger.error(EditorDocumentError.APPLY_CACHE_TO_DIFFERENT_DOCUMENT);
      return;
    }

    const parseRangeFrom = (cacheValue: IDocCacheValue): Range => {
      const [_text, startLineNumber, startColumn, endLineNumber, endColumn] = cacheValue;

      return Range.lift({
        startLineNumber,
        startColumn,
        endLineNumber,
        endColumn,
      });
    };

    if (isDocContentCache(cache)) {
      this.monacoModel.setValue(cache.content);
    } else {
      for (const changes of cache.changeMatrix) {
        const operations = changes.map((change) => ({
          range: parseRangeFrom(change),
          text: change[0],
        }));
        this.monacoModel.applyEdits(operations);
      }
    }
  }

  cleanAndUpdateContent(content) {
    this.monacoModel.setValue(content);
    (this.monacoModel as any)._commandManager.clear();
    this._persistVersionId = this.monacoModel.getAlternativeVersionId();
    this.savingTasks = [];
    this.notifyChangeEvent([], false, false);
    this.baseContent = content;
  }

  async updateEncoding(encoding: string) {
    let shouldFireChange = false;
    if (this._encoding !== encoding) {
      shouldFireChange = true;
    }
    this._encoding = encoding;
    await this.reload();
    if (shouldFireChange) {
      this.eventBus.fire(
        new EditorDocumentModelOptionChangedEvent({
          uri: this.uri,
          encoding: this._encoding,
        }),
      );
      this._onDidChangeEncoding.fire();
    }
  }

  get encoding() {
    return this._encoding;
  }

  set eol(eol) {
    this.monacoModel.setEOL(eol === EOL.LF ? EndOfLineSequence.LF : EndOfLineSequence.CRLF);
    if (!this._isInitOption) {
      this.eventBus.fire(
        new EditorDocumentModelOptionChangedEvent({
          uri: this.uri,
          eol,
        }),
      );
    }
  }

  get eol() {
    return this.monacoModel.getEOL() as EOL;
  }

  get dirty() {
    if (this.alwaysDirty) {
      return true;
    }
    if (!this.savable) {
      return false;
    }
    if (this.monacoModel.isDisposed()) {
      return false;
    }
    /**
     * https://github.com/microsoft/vscode/blob/1.95.3/src/vscode-dts/vscode.d.ts#L14007
     * 如果文档是只读状态，说明并不能进行保存, 自然不需要 dirty 状态
     */
    if (this.readonly) {
      return false;
    }
    return this._persistVersionId !== this.monacoModel.getAlternativeVersionId();
  }

  set languageId(languageId) {
    monaco.editor.setModelLanguage(this.monacoModel, languageId);
    this.eventBus.fire(
      new EditorDocumentModelOptionChangedEvent({
        uri: this.uri,
        languageId,
      }),
    );
  }

  get languageId() {
    return this.monacoModel.getLanguageId();
  }

  get id() {
    return this.monacoModel.id;
  }

  getMonacoModel(): ITextModel {
    return this.monacoModel;
  }

  async syncDocumentModelToExtThread() {
    await this.eventBus.fireAndAwait(
      new EditorDocumentModelOptionChangedEvent({
        uri: this.uri,
        languageId: this.languageId,
        encoding: this.encoding,
        eol: this.eol,
        dirty: this.dirty,
      }),
    );
  }

  async save(force = false, reason: SaveReason = SaveReason.Manual): Promise<boolean> {
    if (!this.dirty) {
      // 如果文档内容没有变化，则只同步新状态到插件进程
      await this.syncDocumentModelToExtThread();
      return false;
    }

    const provider = await this.contentRegistry.getProvider(this.uri);
    const isReadonly = await provider?.isReadonly(this.uri);

    /**
     * 只读文件不允许保存
     * https://github.com/microsoft/vscode/blob/main/src/vscode-dts/vscode.d.ts#L13675
     */
    if (isReadonly) {
      return false;
    }

    const doSave = async (force = false, reason: SaveReason = SaveReason.Manual) => {
      await this.formatOnSave(reason);
      // 发送willSave并等待完成
      await this.eventBus.fireAndAwait(
        new EditorDocumentModelWillSaveEvent({
          uri: this.uri,
          reason,
          language: this.languageId,
          dirty: this.dirty,
        }),
      );
      if (!this.editorPreferences['editor.askIfDiff']) {
        force = true;
      }
      if (!this.dirty) {
        return false;
      }
      const versionId = this.monacoModel.getVersionId();
      const lastSavingTask = this.savingTasks[this.savingTasks.length - 1];
      if (lastSavingTask && lastSavingTask.versionId === versionId) {
        lastSavingTask.cancel();
        const task = this.savingTasks.pop();
        task?.dispose();
      }
      const task = new SaveTask(this.uri, versionId, this.monacoModel.getAlternativeVersionId(), this.getText(), force);
      this.savingTasks.push(task);
      if (this.savingTasks.length > 0) {
        this.initSave();
      }
      const res = await task.finished;
      if (res.state === SaveTaskResponseState.SUCCESS) {
        this.monacoModel.pushStackElement();
        return true;
      } else if (res.state === SaveTaskResponseState.ERROR) {
        if (res.errorMessage !== SaveTaskErrorCause.CANCEL) {
          this.logger.error(res.errorMessage);
          this.messageService.error(localize('doc.saveError.failed') + '\n' + res.errorMessage);
        }
        return false;
      } else if (res.state === SaveTaskResponseState.DIFF) {
        const diffAndSave = localize('doc.saveError.diffAndSave');
        const overwrite = localize('doc.saveError.overwrite');
        this.messageService
          .error(formatLocalize('doc.saveError.diff', this.uri.toString()), [diffAndSave, overwrite])
          .then((res) => {
            if (res === diffAndSave) {
              this.compareAndSave();
            } else if (res === overwrite) {
              doSave(true, reason);
            }
          });
        this.logger.error('The file cannot be saved, the version is inconsistent with the disk');
        return false;
      }
      return false;
    };
    return this.saveQueue.queue(doSave.bind(this, force, reason));
  }

  private async compareAndSave() {
    const originalUri = URI.from({
      scheme: ORIGINAL_DOC_SCHEME,
      query: URI.stringifyQuery({
        target: this.uri.toString(),
      }),
    });
    const fileName = this.uri.path.base;
    const res = await this.compareService.compare(
      originalUri,
      this.uri,
      formatLocalize('editor.compareAndSave.title', fileName, fileName),
    );
    if (res === CompareResult.revert) {
      this.revert();
    } else if (res === CompareResult.accept) {
      this.save(true);
    }
  }

  async initSave() {
    while (this.savingTasks.length > 0) {
      const changes = this.dirtyChanges;
      this.dirtyChanges = [];
      const res = await this.savingTasks[0].run(this.service, this.baseContent, changes, this.encoding, this.eol);
      if (res.state === 'success' && this.savingTasks[0]) {
        this.baseContent = this.savingTasks[0].content;

        this.eventBus.fire(new EditorDocumentModelSavedEvent(this.uri));
        this.setPersist(this.savingTasks[0].alternativeVersionId);
      } else {
        // 回滚 changes
        this.dirtyChanges.unshift(...changes);
      }
      this.savingTasks.shift();
    }
  }

  setPersist(versionId: number) {
    this._persistVersionId = versionId;
    this.notifyChangeEvent([], false, false);
  }

  async reload() {
    try {
      const content = await this.contentRegistry.getContentForUri(this.uri, this._encoding);
      if (!isUndefinedOrNull(content)) {
        this.cleanAndUpdateContent(content);
      }
    } catch (e) {
      this._persistVersionId = this.monacoModel.getAlternativeVersionId();
    }
  }

  async revert(notOnDisk?: boolean) {
    if (notOnDisk) {
      // FIXME: 暂时就让它不 dirty, 不是真正的 revert
      this._persistVersionId = this.monacoModel.getAlternativeVersionId();
    } else {
      // 利用修改编码的副作用
      await this.updateEncoding(this._originalEncoding);
    }
  }

  getText(range?: IRange) {
    if (range) {
      return this.monacoModel.getValueInRange(range);
    } else {
      return this.monacoModel.getValue();
    }
  }

  updateContent(content: string, eol?: EOL, setPersist = false) {
    if (eol) {
      this.eol = eol;
    }

    const defaultEOL = this.eol === EOL.CRLF ? DefaultEndOfLine.CRLF : DefaultEndOfLine.LF;
    const { textBuffer, disposable } = createTextBuffer(content, defaultEOL);
    // 计算新旧 Monaco 文档的差异，避免全量更新导致的高亮闪烁问题
    const singleEditOperation = EditorDocumentModel._computeEdits(this.monacoModel, textBuffer);
    this.monacoModel.pushEditOperations([], singleEditOperation, () => []);

    if (setPersist) {
      this.setPersist(this.monacoModel.getAlternativeVersionId());
      this.baseContent = content;
      this.dirtyChanges = [];
    }
    disposable.dispose();
  }

  /**
   * Compute edits to bring `model` to the state of `textSource`.
   */
  public static _computeEdits(model: ITextModel, textBuffer: ITextBuffer): ISingleEditOperation[] {
    const modelLineCount = model.getLineCount();
    const textBufferLineCount = textBuffer.getLineCount();
    const commonPrefix = this._commonPrefix(model, modelLineCount, 1, textBuffer, textBufferLineCount, 1);

    if (modelLineCount === textBufferLineCount && commonPrefix === modelLineCount) {
      // equality case
      return [];
    }

    const commonSuffix = this._commonSuffix(
      model,
      modelLineCount - commonPrefix,
      commonPrefix,
      textBuffer,
      textBufferLineCount - commonPrefix,
      commonPrefix,
    );

    let oldRange: Range;
    let newRange: Range;
    if (commonSuffix > 0) {
      oldRange = new Range(commonPrefix + 1, 1, modelLineCount - commonSuffix + 1, 1);
      newRange = new Range(commonPrefix + 1, 1, textBufferLineCount - commonSuffix + 1, 1);
    } else if (commonPrefix > 0) {
      oldRange = new Range(
        commonPrefix,
        model.getLineMaxColumn(commonPrefix),
        modelLineCount,
        model.getLineMaxColumn(modelLineCount),
      );
      newRange = new Range(
        commonPrefix,
        1 + textBuffer.getLineLength(commonPrefix),
        textBufferLineCount,
        1 + textBuffer.getLineLength(textBufferLineCount),
      );
    } else {
      oldRange = new Range(1, 1, modelLineCount, model.getLineMaxColumn(modelLineCount));
      newRange = new Range(1, 1, textBufferLineCount, 1 + textBuffer.getLineLength(textBufferLineCount));
    }

    return [EditOperation.replaceMove(oldRange, textBuffer.getValueInRange(newRange, EndOfLinePreference.TextDefined))];
  }

  private static _commonPrefix(
    a: ITextModel,
    aLen: number,
    aDelta: number,
    b: ITextBuffer,
    bLen: number,
    bDelta: number,
  ): number {
    const maxResult = Math.min(aLen, bLen);

    let result = 0;
    for (let i = 0; i < maxResult && a.getLineContent(aDelta + i) === b.getLineContent(bDelta + i); i++) {
      result++;
    }
    return result;
  }

  private static _commonSuffix(
    a: ITextModel,
    aLen: number,
    aDelta: number,
    b: ITextBuffer,
    bLen: number,
    bDelta: number,
  ): number {
    const maxResult = Math.min(aLen, bLen);

    let result = 0;
    for (let i = 0; i < maxResult && a.getLineContent(aDelta + aLen - i) === b.getLineContent(bDelta + bLen - i); i++) {
      result++;
    }
    return result;
  }

  set baseContent(content: string) {
    this._baseContent = content;
    this._baseContentMd5 = null;
  }

  get baseContent() {
    return this._baseContent;
  }

  get baseContentMd5() {
    if (!this._baseContentMd5) {
      this._baseContentMd5 = this.hashCalculateService.calculate(this._baseContent);
    }
    return this._baseContentMd5;
  }

  get tryAutoSaveAfterDelay() {
    if (!this._tryAutoSaveAfterDelay) {
      this._tryAutoSaveAfterDelay = debounce(() => {
        this.save(undefined, SaveReason.AfterDelay);
      }, this.editorPreferences['editor.autoSaveDelay'] || 1000);
      this.addDispose(
        this.editorPreferences.onPreferenceChanged((change) => {
          if (change.preferenceName === 'editor.autoSaveDelay') {
            this._tryAutoSaveAfterDelay = debounce(() => {
              this.save(undefined, SaveReason.AfterDelay);
            }, this.editorPreferences['editor.autoSaveDelay'] || 1000);
          }
        }),
      );
    }
    return this._tryAutoSaveAfterDelay;
  }

  getBaseContentMd5(): string {
    if (!this._baseContentMd5) {
      this._baseContentMd5 = this.hashCalculateService.calculate(this._baseContent);
    }
    return this._baseContentMd5!;
  }

  private notifyChangeEvent(changes: IEditorDocumentModelContentChange[] = [], isRedoing: boolean, isUndoing: boolean) {
    if (
      !this.closeAutoSave &&
      this.savable &&
      this.editorPreferences['editor.autoSave'] === AUTO_SAVE_MODE.AFTER_DELAY
    ) {
      this.tryAutoSaveAfterDelay();
    }
    // 发出内容变化的事件
    this.eventBus.fire(
      new EditorDocumentModelContentChangedEvent({
        uri: this.uri,
        dirty: this.dirty,
        readonly: this.readonly,
        changes,
        eol: this.eol,
        isRedoing,
        isUndoing,
        versionId: this.monacoModel.getVersionId(),
      }),
    );

    const self = this;
    this.cacheProvider.persistCache(this.uri, {
      // 使用 getter 让需要计算的数据变成 lazy 获取的
      get dirty() {
        return self.dirty;
      },
      get startMD5() {
        return self.getBaseContentMd5();
      },
      get content() {
        return self.getText();
      },
      get changeMatrix() {
        // 计算从起始版本到现在所有的 change 内容，然后让缓存对象进行持久化
        return self.dirtyChanges.map(({ changes }) => changes);
      },
      encoding: this.encoding,
    });
  }

  protected async formatOnSave(reason: SaveReason) {
    const formatOnSave = this.editorPreferences['editor.formatOnSave'];

    // 和 vscode 逻辑保持一致，如果是 AfterDelay 则不执行 formatOnSave
    if (formatOnSave && reason !== SaveReason.AfterDelay) {
      const formatOnSaveTimeout = this.editorPreferences['editor.formatOnSaveTimeout'] || 3000;
      const timer = this.reporter.time(REPORT_NAME.FORMAT_ON_SAVE);
      try {
        await Promise.race([
          new Promise((_, reject) => {
            setTimeout(() => {
              const err = new Error(formatLocalize('preference.editor.formatOnSaveTimeoutError', formatOnSaveTimeout));
              err.name = 'FormatOnSaveTimeoutError';
              reject(err);
            }, formatOnSaveTimeout);
          }),
          this.commandService.executeCommand(EDITOR_COMMANDS.FORMAT_DOCUMENT.id),
        ]);
      } catch (err) {
        if (err.name === 'FormatOnSaveTimeoutError') {
          this.reporter.point(REPORT_NAME.FORMAT_ON_SAVE_TIMEOUT_ERROR, this.uri.toString());
        }
        // 目前 command 没有读取到 contextkey，在不支持 format 的地方执行 format 命令会报错，先警告下，后续要接入 contextkey 来判断
        this.logger.warn(`${EditorDocumentError.FORMAT_ERROR} ${err && err.message}`);
      } finally {
        timer.timeEnd(this.uri.path.ext);
      }
    }
  }
}