import { Autowired, Injectable } from '@opensumi/di';
import {
  IApplicationService,
  LRUMap,
  MessageType,
  OperatingSystem,
  URI,
  WithEventBus,
  formatLocalize,
  localize,
} from '@opensumi/ide-core-browser';
import { LabelService } from '@opensumi/ide-core-browser/lib/services';
import { FileChangeType, path } from '@opensumi/ide-core-common';
import { FileStat, IFileServiceClient } from '@opensumi/ide-file-service/lib/common';
import { IDialogService } from '@opensumi/ide-overlay';

import { AskSaveResult, DIFF_SCHEME, IResource, IResourceProvider, ResourceNeedUpdateEvent } from '../../common';
import { IEditorDocumentModelService } from '../doc-model/types';

import { FileTreeSet } from './file-tree-set';

const { Path } = path;

@Injectable()
export class FileSystemResourceProvider extends WithEventBus implements IResourceProvider {
  private static SUBNAME_LIMIT = 20;

  @Autowired()
  protected labelService: LabelService;

  @Autowired(IFileServiceClient)
  protected fileServiceClient: IFileServiceClient;

  @Autowired(IDialogService)
  protected dialogService: IDialogService;

  @Autowired(IEditorDocumentModelService)
  protected documentModelService: IEditorDocumentModelService;

  @Autowired(IApplicationService)
  protected applicationService: IApplicationService;

  cachedFileStat = new LRUMap<string, FileStat | undefined>(200, 100);

  private involvedFiles: FileTreeSet;

  private ready: Promise<void>;

  private userhomePath: URI | null;

  constructor() {
    super();
    this.ready = this.init();
    this.listen();
  }

  async init() {
    const os = await this.applicationService.getBackendOS();
    this.involvedFiles = new FileTreeSet(os === OperatingSystem.Windows);
  }

  handlesUri(uri: URI): number {
    const scheme = uri.scheme;
    if (this.fileServiceClient.handlesScheme(scheme)) {
      return 10;
    } else {
      return -1;
    }
  }

  protected listen() {
    this.fileServiceClient.onFilesChanged((e) => {
      e.forEach((change) => {
        if (change.type === FileChangeType.ADDED || change.type === FileChangeType.DELETED) {
          // 对于文件夹的删除，做要传递给子文件
          const effectedPaths = this.involvedFiles?.effects(new URI(change.uri).codeUri.fsPath);
          effectedPaths.forEach((p) => {
            const effected = URI.file(p);
            this.cachedFileStat.delete(effected.toString());
            this.eventBus.fire(new ResourceNeedUpdateEvent(effected));
          });
        } else {
          // Linux下，可能 update 事件代表了 create
          // 此时如果 cached 是undefined，就更新
          if (this.cachedFileStat.has(change.uri) && this.cachedFileStat.get(change.uri) === undefined) {
            this.cachedFileStat.delete(change.uri);
            this.eventBus.fire(new ResourceNeedUpdateEvent(new URI(change.uri)));
          }
        }
      });
    });
    this.labelService.onDidChange((uri) => {
      if (uri.codeUri.fsPath && this.involvedFiles?.effects(uri.codeUri.fsPath)) {
        this.eventBus.fire(new ResourceNeedUpdateEvent(uri));
      }
    });
  }

  async getFileStat(uri: string) {
    if (!this.cachedFileStat.has(uri)) {
      this.cachedFileStat.set(uri, await this.fileServiceClient.getFileStat(uri.toString()));
    }
    return this.cachedFileStat.get(uri);
  }

  private async getCurrentUserHome() {
    if (!this.userhomePath) {
      try {
        const userhome = await this.fileServiceClient.getCurrentUserHome();
        if (userhome) {
          this.userhomePath = new URI(userhome.uri);
        }
      } catch (err) {}
    }
    return this.userhomePath;
  }

  private async getReadableTooltip(path: URI) {
    const pathStr = path.toString();
    const userhomePath = await this.getCurrentUserHome();
    if (!userhomePath) {
      return decodeURIComponent(path.withScheme('').toString());
    }
    if (userhomePath.isEqualOrParent(path)) {
      const userhomePathStr = userhomePath && userhomePath.toString();
      return decodeURIComponent(pathStr.replace(userhomePathStr, '~'));
    }
    return decodeURIComponent(path.withScheme('').toString());
  }

  async provideResource(uri: URI): Promise<IResource<any>> {
    await this.ready;
    this.involvedFiles.add(uri.codeUri.fsPath);
    return Promise.all([
      this.getFileStat(uri.toString()),
      this.labelService.getName(uri),
      this.labelService.getIcon(uri),
      this.getReadableTooltip(uri),
    ] as const).then(([stat, name, icon, title]) => ({
      name: stat ? name : name + localize('file.resource-deleted', '(已删除)'),
      icon,
      uri,
      metadata: null,
      deleted: !stat,
      supportsRevive: true,
      title,
    }));
  }

  provideResourceSubname(resource: IResource, groupResources: IResource[]): string | null {
    const shouldDiff: URI[] = [];
    for (const res of groupResources) {
      if (
        this.fileServiceClient.handlesScheme(res.uri.scheme) &&
        res.uri.displayName === resource.uri.displayName &&
        res !== resource
      ) {
        // 存在file协议的相同名称的文件
        shouldDiff.push(res.uri);
      }
    }
    if (shouldDiff.length > 0) {
      const tail = getMinimalDiffPath(resource.uri, shouldDiff);
      if (tail.startsWith(Path.separator)) {
        // 说明当前为全路径
        if (tail.length > FileSystemResourceProvider.SUBNAME_LIMIT) {
          return '...' + tail.slice(tail.length - FileSystemResourceProvider.SUBNAME_LIMIT);
        } else {
          return tail;
        }
      } else {
        return '...' + Path.separator + getMinimalDiffPath(resource.uri, shouldDiff);
      }
    } else {
      return null;
    }
  }

  onDisposeResource(resource) {
    this.involvedFiles?.delete(resource.uri.codeUri.fsPath);
    this.cachedFileStat.delete(resource.uri.toString());
  }
  async shouldCloseResourceWithoutConfirm(resource: IResource) {
    const documentModelRef = this.documentModelService.getModelDescription(resource.uri, 'close-resource-check');
    if (documentModelRef && documentModelRef.dirty) {
      return true;
    }
    return false;
  }
  async close(resource: IResource, saveAction?: AskSaveResult) {
    const documentModelRef = this.documentModelService.getModelReference(resource.uri, 'close-resource-check');
    if (!documentModelRef) {
      return false;
    }
    if (saveAction === AskSaveResult.SAVE) {
      const res = await documentModelRef.instance.save();
      documentModelRef.dispose();
      return res;
    } else if (saveAction === AskSaveResult.REVERT) {
      await documentModelRef.instance.revert();
      documentModelRef.dispose();
      return true;
    } else if (!saveAction || saveAction === AskSaveResult.CANCEL) {
      documentModelRef.dispose();
      return false;
    } else {
      documentModelRef.dispose();
      return true;
    }
  }
  async shouldCloseResource(resource: IResource, openedResources: IResource[][]): Promise<boolean> {
    let count = 0;
    for (const resources of openedResources) {
      for (const r of resources) {
        if (r.uri.scheme === DIFF_SCHEME && r.metadata && r.metadata.modified.toString() === resource.uri.toString()) {
          count++;
        }
        if (this.fileServiceClient.handlesScheme(r.uri.scheme) && r.uri.toString() === resource.uri.toString()) {
          count++;
        }
        if (count > 1) {
          return true;
        }
      }
    }
    const documentModelRef = this.documentModelService.getModelDescription(resource.uri, 'close-resource-check');
    if (!documentModelRef || !documentModelRef.dirty) {
      return true;
    }

    // 询问用户是否保存
    const buttons = {
      [localize('file.prompt.dontSave', "Don't Save")]: AskSaveResult.REVERT,
      [localize('file.prompt.save', 'Save')]: AskSaveResult.SAVE,
      [localize('file.prompt.cancel', 'Cancel')]: AskSaveResult.CANCEL,
    };
    const selection = await this.dialogService.open({
      message: formatLocalize('saveChangesMessage', resource.name),
      type: MessageType.Info,
      buttons: Object.keys(buttons),
    });
    const result = buttons[selection!];
    return this.close(resource, result);
  }
}

/**
 * 找到 source 文件 url 和中从末尾开始和 target 不一样的 path
 * @param source
 * @param targets
 */
function getMinimalDiffPath(source: URI, targets: URI[]): string {
  const sourceDirPartsReverse = source.path.dir.toString().split(Path.separator).reverse();
  const targetDirPartsReverses = targets.map((target) => target.path.dir.toString().split(Path.separator).reverse());
  for (let i = 0; i < sourceDirPartsReverse.length; i++) {
    let foundSame = false;
    for (const targetDirPartsReverse of targetDirPartsReverses) {
      if (targetDirPartsReverse[i] === sourceDirPartsReverse[i]) {
        foundSame = true;
        break;
      }
    }
    if (!foundSame) {
      return sourceDirPartsReverse
        .slice(0, i + 1)
        .reverse()
        .join(Path.separator);
    }
  }
  return sourceDirPartsReverse.reverse().join(Path.separator);
}