client.ts

// Third party web dependencies
import {
  CompletionContext,
  CompletionResult,
  EditorView,
  gitIgnoreCompiler,
  syntaxTree,
} from "../common/deps.ts";
import { fileMetaToPageMeta, Space } from "./space.ts";
import { FilterOption, PageMeta } from "./types.ts";
import { parseYamlSettings } from "../common/util.ts";
import { EventHook } from "../plugos/hooks/event.ts";
import { AppCommand } from "./hooks/command.ts";
import { PathPageNavigator } from "./navigator.ts";

import { AppViewState, BuiltinSettings } from "./types.ts";

import type { AppEvent, CompleteEvent } from "../plug-api/app_event.ts";
import { throttle } from "$sb/lib/async.ts";
import { PlugSpacePrimitives } from "../common/spaces/plug_space_primitives.ts";
import { IndexedDBSpacePrimitives } from "../common/spaces/indexeddb_space_primitives.ts";
import { FileMetaSpacePrimitives } from "../common/spaces/file_meta_space_primitives.ts";
import { EventedSpacePrimitives } from "../common/spaces/evented_space_primitives.ts";
import {
  ISyncService,
  NoSyncSyncService,
  pageSyncInterval,
  SyncService,
} from "./sync_service.ts";
import { simpleHash } from "../common/crypto.ts";
import { DexieKVStore } from "../plugos/lib/kv_store.dexie.ts";
import { SyncStatus } from "../common/spaces/sync.ts";
import { HttpSpacePrimitives } from "../common/spaces/http_space_primitives.ts";
import { FallbackSpacePrimitives } from "../common/spaces/fallback_space_primitives.ts";
import { FilteredSpacePrimitives } from "../common/spaces/filtered_space_primitives.ts";
import { validatePageName } from "$sb/lib/page.ts";
import { ClientSystem } from "./client_system.ts";
import { createEditorState } from "./editor_state.ts";
import { OpenPages } from "./open_pages.ts";
import { MainUI } from "./editor_ui.tsx";
import { DexieMQ } from "../plugos/lib/mq.dexie.ts";
import { cleanPageRef } from "$sb/lib/resolve.ts";
import { expandPropertyNames } from "$sb/lib/json.ts";
import { SpacePrimitives } from "../common/spaces/space_primitives.ts";
import { FileMeta } from "$sb/types.ts";
const frontMatterRegex = /^---\n(([^\n]|\n)*?)---\n/;

const autoSaveInterval = 1000;

declare global {
  interface Window {
    // Injected via index.html
    silverBulletConfig: {
      spaceFolderPath: string;
      syncOnly: boolean;
    };
    client: Client;
  }
}

// TODO: Oh my god, need to refactor this
export class Client {
  system: ClientSystem;
  editorView: EditorView;
  private pageNavigator!: PathPageNavigator;

  private dbPrefix: string;

  plugSpaceRemotePrimitives!: PlugSpacePrimitives;
  // localSpacePrimitives!: FilteredSpacePrimitives;
  remoteSpacePrimitives!: HttpSpacePrimitives;
  space!: Space;

  saveTimeout?: number;
  debouncedUpdateEvent = throttle(() => {
    this.eventHook
      .dispatchEvent("editor:updated")
      .catch((e) => console.error("Error dispatching editor:updated event", e));
  }, 1000);

  // Track if plugs have been updated since sync cycle
  fullSyncCompleted = false;

  syncService: ISyncService;
  settings!: BuiltinSettings;
  kvStore: DexieKVStore;
  mq: DexieMQ;

  // Event bus used to communicate between components
  eventHook: EventHook;

  ui: MainUI;
  openPages: OpenPages;

  constructor(
    parent: Element,
    public syncMode = false,
  ) {
    if (!syncMode) {
      this.fullSyncCompleted = true;
    }
    // Generate a semi-unique prefix for the database so not to reuse databases for different space paths
    this.dbPrefix = "" + simpleHash(window.silverBulletConfig.spaceFolderPath);

    this.kvStore = new DexieKVStore(
      `${this.dbPrefix}_store`,
      "data",
      globalThis.indexedDB,
      globalThis.IDBKeyRange,
    );

    this.mq = new DexieMQ(`${this.dbPrefix}_mq`, indexedDB, IDBKeyRange);

    setInterval(() => {
      // Timeout after 5s, retries 3 times, otherwise drops the message (no DLQ)
      this.mq.requeueTimeouts(5000, 3, true).catch(console.error);
    }, 20000); // Look to requeue every 20s

    // Event hook
    this.eventHook = new EventHook();

    // Instantiate a PlugOS system
    this.system = new ClientSystem(
      this,
      this.kvStore,
      this.mq,
      this.dbPrefix,
      this.eventHook,
    );

    const localSpacePrimitives = this.initSpace();

    this.syncService = this.syncMode
      ? new SyncService(
        localSpacePrimitives,
        this.plugSpaceRemotePrimitives,
        this.kvStore,
        this.eventHook,
        (path) => {
          // TODO: At some point we should remove the data.db exception here
          return path !== "data.db" &&
              // Exclude all plug space primitives paths
              !this.plugSpaceRemotePrimitives.isLikelyHandled(path) ||
            // Except federated ones
            path.startsWith("!");
        },
      )
      : new NoSyncSyncService(this.space);

    this.ui = new MainUI(this);
    this.ui.render(parent);

    this.editorView = new EditorView({
      state: createEditorState(this, "", "", false),
      parent: document.getElementById("sb-editor")!,
    });

    this.openPages = new OpenPages(this);

    this.focus();

    // This constructor will always be followed by an (async) invocatition of init()
  }

  /**
   * Initialize the client
   * This is a separated from the constructor to allow for async initialization
   */
  async init() {
    // Load settings
    this.settings = await this.loadSettings();

    // Pinging a remote space to ensure we're authenticated properly, if not will result in a redirect to auth page
    try {
      await this.remoteSpacePrimitives.ping();
    } catch (e: any) {
      if (e.message === "Not authenticated") {
        console.warn("Not authenticated, redirecting to auth page");
        return;
      }
      console.warn(
        "Could not reach remote server, we're offline or the server is down",
        e,
      );
    }

    await this.loadPlugs();
    this.initNavigator();
    this.initSync();

    this.loadCustomStyles().catch(console.error);

    await this.dispatchAppEvent("editor:init");

    setInterval(() => {
      // console.log("Syncing page", this.currentPage, "in background");
      try {
        this.syncService.syncFile(`${this.currentPage!}.md`).catch((e: any) => {
          console.error("Interval sync error", e);
        });
      } catch (e: any) {
        console.error("Interval sync error", e);
      }
      // console.log("End of kick-off of background sync of", this.currentPage);
    }, pageSyncInterval);
  }

  private initSync() {
    this.syncService.start();

    this.eventHook.addLocalListener("sync:success", async (operations) => {
      // console.log("Operations", operations);
      if (operations > 0) {
        // Update the page list
        await this.space.updatePageList();
      }
      if (operations !== undefined) {
        // "sync:success" is called with a number of operations only from syncSpace(), not from syncing individual pages
        this.fullSyncCompleted = true;
      }
      if (this.system.plugsUpdated) {
        // To register new commands, update editor state based on new plugs
        this.rebuildEditorState();
        this.dispatchAppEvent(
          "editor:pageLoaded",
          this.currentPage,
          undefined,
          true,
        );
        if (operations) {
          // Likely initial sync so let's show visually that we're synced now
          // this.flashNotification(`Synced ${operations} files`, "info");
          this.showProgress(100);
        }
      }
      // Reset for next sync cycle
      this.system.plugsUpdated = false;

      this.ui.viewDispatch({ type: "sync-change", syncSuccess: true });
    });
    this.eventHook.addLocalListener("sync:error", (_name) => {
      this.ui.viewDispatch({ type: "sync-change", syncSuccess: false });
    });
    this.eventHook.addLocalListener("sync:conflict", (name) => {
      this.flashNotification(
        `Sync: conflict detected for ${name} - conflict copy created`,
        "error",
      );
    });
    this.eventHook.addLocalListener("sync:progress", (status: SyncStatus) => {
      this.showProgress(
        Math.round(status.filesProcessed / status.totalFiles * 100),
      );
    });
    this.eventHook.addLocalListener(
      "file:synced",
      (meta: FileMeta, direction: string) => {
        if (meta.name.endsWith(".md") && direction === "secondary->primary") {
          // We likely polled the currently open page which trigggered a local update, let's update the editor accordingly
          this.space.getPageMeta(meta.name.slice(0, -3));
        }
      },
    );
  }

  private initNavigator() {
    this.pageNavigator = new PathPageNavigator(
      cleanPageRef(this.settings.indexPage),
    );

    this.pageNavigator.subscribe(async (pageName, pos: number | string) => {
      console.log("Now navigating to", pageName);

      const stateRestored = await this.loadPage(pageName);
      if (pos) {
        if (typeof pos === "string") {
          console.log("Navigating to anchor", pos);

          // We're going to look up the anchor through a direct page store query...
          // TODO: This should be extracted
          const posLookup = await this.system.localSyscall(
            "index.get",
            [
              pageName,
              `a:${pageName}:${pos}`,
            ],
          );

          if (!posLookup) {
            return this.flashNotification(
              `Could not find anchor @${pos}`,
              "error",
            );
          } else {
            pos = +posLookup;
          }
        }
        this.editorView.dispatch({
          selection: { anchor: pos },
          effects: EditorView.scrollIntoView(pos, { y: "start" }),
        });
      } else if (!stateRestored) {
        // Somewhat ad-hoc way to determine if the document contains frontmatter and if so, putting the cursor _after it_.
        const pageText = this.editorView.state.sliceDoc();

        // Default the cursor to be at position 0
        let initialCursorPos = 0;
        const match = frontMatterRegex.exec(pageText);
        if (match) {
          // Frontmatter found, put cursor after it
          initialCursorPos = match[0].length;
        }
        // By default scroll to the top
        this.editorView.scrollDOM.scrollTop = 0;
        this.editorView.dispatch({
          selection: { anchor: initialCursorPos },
          // And then scroll down if required
          scrollIntoView: true,
        });
      }
      await this.kvStore.set("lastOpenedPage", pageName);
    });

    if (location.hash === "#boot") {
      (async () => {
        // Cold start PWA load
        const lastPage = await this.kvStore.get("lastOpenedPage");
        if (lastPage) {
          await this.navigate(lastPage);
        }
      })().catch(console.error);
    }
  }

  initSpace(): SpacePrimitives {
    this.remoteSpacePrimitives = new HttpSpacePrimitives(
      location.origin,
      window.silverBulletConfig.spaceFolderPath,
    );

    this.plugSpaceRemotePrimitives = new PlugSpacePrimitives(
      this.remoteSpacePrimitives,
      this.system.namespaceHook,
    );

    let fileFilterFn: (s: string) => boolean = () => true;

    let localSpacePrimitives: SpacePrimitives | undefined;

    if (this.syncMode) {
      localSpacePrimitives = new FilteredSpacePrimitives(
        new FileMetaSpacePrimitives(
          new EventedSpacePrimitives(
            // Using fallback space primitives here to allow (by default) local reads to "fall through" to HTTP when files aren't synced yet
            new FallbackSpacePrimitives(
              new IndexedDBSpacePrimitives(
                `${this.dbPrefix}_space`,
                globalThis.indexedDB,
              ),
              this.plugSpaceRemotePrimitives,
            ),
            this.eventHook,
          ),
          this.system.indexSyscalls,
        ),
        (meta) => fileFilterFn(meta.name),
        // Run when a list of files has been retrieved
        async () => {
          await this.loadSettings();
          if (typeof this.settings?.spaceIgnore === "string") {
            fileFilterFn = gitIgnoreCompiler(this.settings.spaceIgnore).accepts;
          } else {
            fileFilterFn = () => true;
          }
        },
      );
    } else {
      localSpacePrimitives = new EventedSpacePrimitives(
        this.plugSpaceRemotePrimitives,
        this.eventHook,
      );
    }

    this.space = new Space(localSpacePrimitives, this.kvStore, this.eventHook);

    this.eventHook.addLocalListener("file:changed", (path: string) => {
      // Only reload when watching the current page (to avoid reloading when switching pages)
      if (
        this.space.watchInterval && `${this.currentPage}.md` === path
      ) {
        console.log("Page changed elsewhere, reloading");
        this.flashNotification("Page changed elsewhere, reloading");
        this.reloadPage();
      }
    });

    this.eventHook.addLocalListener("file:listed", (fileList: FileMeta[]) => {
      this.ui.viewDispatch({
        type: "pages-listed",
        pages: fileList.filter((f) => f.name.endsWith(".md")).map(
          fileMetaToPageMeta,
        ),
      });
    });

    this.space.watch();

    return localSpacePrimitives;
  }

  async loadSettings(): Promise<BuiltinSettings> {
    let settingsText: string | undefined;

    try {
      settingsText = (await this.space.readPage("SETTINGS")).text;
    } catch (e) {
      console.info("No SETTINGS page, falling back to default", e);
      settingsText = '```yaml\nindexPage: "[[index]]"\n```\n';
    }
    let settings = parseYamlSettings(settingsText!) as BuiltinSettings;

    settings = expandPropertyNames(settings);

    // console.log("Settings", settings);

    if (!settings.indexPage) {
      settings.indexPage = "[[index]]";
    }
    return settings;
  }

  get currentPage(): string | undefined {
    return this.ui.viewState.currentPage;
  }

  dispatchAppEvent(name: AppEvent, ...args: any[]): Promise<any[]> {
    return this.eventHook.dispatchEvent(name, ...args);
  }

  save(immediate = false): Promise<void> {
    return new Promise((resolve, reject) => {
      if (this.saveTimeout) {
        clearTimeout(this.saveTimeout);
      }
      this.saveTimeout = setTimeout(
        () => {
          if (this.currentPage) {
            if (
              !this.ui.viewState.unsavedChanges ||
              this.ui.viewState.uiOptions.forcedROMode
            ) {
              // No unsaved changes, or read-only mode, not gonna save
              return resolve();
            }
            console.log("Saving page", this.currentPage);
            this.space
              .writePage(
                this.currentPage,
                this.editorView.state.sliceDoc(0),
                true,
              )
              .then(async (meta) => {
                this.ui.viewDispatch({ type: "page-saved" });
                await this.dispatchAppEvent(
                  "editor:pageSaved",
                  this.currentPage,
                  meta,
                );
                resolve();
              })
              .catch((e) => {
                this.flashNotification(
                  "Could not save page, retrying again in 10 seconds",
                  "error",
                );
                this.saveTimeout = setTimeout(this.save.bind(this), 10000);
                reject(e);
              });
          } else {
            resolve();
          }
        },
        immediate ? 0 : autoSaveInterval,
      );
    });
  }

  flashNotification(message: string, type: "info" | "error" = "info") {
    const id = Math.floor(Math.random() * 1000000);
    this.ui.viewDispatch({
      type: "show-notification",
      notification: {
        id,
        type,
        message,
        date: new Date(),
      },
    });
    setTimeout(
      () => {
        this.ui.viewDispatch({
          type: "dismiss-notification",
          id: id,
        });
      },
      type === "info" ? 4000 : 5000,
    );
  }

  private progressTimeout?: number;
  showProgress(progressPerc: number) {
    this.ui.viewDispatch({
      type: "set-progress",
      progressPerc,
    });
    if (this.progressTimeout) {
      clearTimeout(this.progressTimeout);
    }
    this.progressTimeout = setTimeout(
      () => {
        this.ui.viewDispatch({
          type: "set-progress",
        });
      },
      10000,
    );
  }

  filterBox(
    label: string,
    options: FilterOption[],
    helpText = "",
    placeHolder = "",
  ): Promise<FilterOption | undefined> {
    return new Promise((resolve) => {
      this.ui.viewDispatch({
        type: "show-filterbox",
        label,
        options,
        placeHolder,
        helpText,
        onSelect: (option: any) => {
          this.ui.viewDispatch({ type: "hide-filterbox" });
          this.focus();
          resolve(option);
        },
      });
    });
  }

  prompt(
    message: string,
    defaultValue = "",
  ): Promise<string | undefined> {
    return new Promise((resolve) => {
      this.ui.viewDispatch({
        type: "show-prompt",
        message,
        defaultValue,
        callback: (value: string | undefined) => {
          this.ui.viewDispatch({ type: "hide-prompt" });
          this.focus();
          resolve(value);
        },
      });
    });
  }

  confirm(
    message: string,
  ): Promise<boolean> {
    return new Promise((resolve) => {
      this.ui.viewDispatch({
        type: "show-confirm",
        message,
        callback: (value: boolean) => {
          this.ui.viewDispatch({ type: "hide-confirm" });
          this.focus();
          resolve(value);
        },
      });
    });
  }

  async loadPlugs() {
    await this.system.reloadPlugsFromSpace(this.space);
    this.rebuildEditorState();
    await this.dispatchAppEvent("plugs:loaded");
  }

  rebuildEditorState() {
    const editorView = this.editorView;
    console.log("Rebuilding editor state");

    this.system.updateMarkdownParser();

    if (this.currentPage) {
      // And update the editor if a page is loaded
      this.openPages.saveState(this.currentPage);

      editorView.setState(
        createEditorState(
          this,
          this.currentPage,
          editorView.state.sliceDoc(),
          this.ui.viewState.currentPageMeta?.perm === "ro",
        ),
      );
      if (editorView.contentDOM) {
        this.tweakEditorDOM(
          editorView.contentDOM,
        );
      }

      this.openPages.restoreState(this.currentPage);
    }
  }

  // Code completion support
  private async completeWithEvent(
    context: CompletionContext,
    eventName: AppEvent,
  ): Promise<CompletionResult | null> {
    const editorState = context.state;
    const selection = editorState.selection.main;
    const line = editorState.doc.lineAt(selection.from);
    const linePrefix = line.text.slice(0, selection.from - line.from);

    const parentNodes: string[] = [];
    const currentNode = syntaxTree(editorState).resolveInner(selection.from);
    if (currentNode) {
      let node = currentNode;
      while (node.parent) {
        parentNodes.push(node.parent.name);
        node = node.parent;
      }
    }

    const results = await this.dispatchAppEvent(eventName, {
      pageName: this.currentPage!,
      linePrefix,
      pos: selection.from,
      parentNodes,
    } as CompleteEvent);
    let actualResult = null;
    for (const result of results) {
      if (result) {
        if (actualResult) {
          console.error(
            "Got completion results from multiple sources, cannot deal with that",
          );
          console.error("Previously had", actualResult, "now also got", result);
          return null;
        }
        actualResult = result;
      }
    }
    return actualResult;
  }

  editorComplete(
    context: CompletionContext,
  ): Promise<CompletionResult | null> {
    return this.completeWithEvent(context, "editor:complete");
  }

  miniEditorComplete(
    context: CompletionContext,
  ): Promise<CompletionResult | null> {
    return this.completeWithEvent(context, "minieditor:complete");
  }

  async reloadPage() {
    console.log("Reloading page");
    clearTimeout(this.saveTimeout);
    await this.loadPage(this.currentPage!);
  }

  focus() {
    const viewState = this.ui.viewState;
    if (
      [
        viewState.showCommandPalette,
        viewState.showPageNavigator,
        viewState.showFilterBox,
        viewState.showConfirm,
        viewState.showPrompt,
      ].some(Boolean)
    ) {
      // Some other modal UI element is visible, don't focus editor now
      return;
    }
    this.editorView.focus();
  }

  async navigate(
    name: string,
    pos?: number | string,
    replaceState = false,
    newWindow = false,
  ) {
    if (!name) {
      name = cleanPageRef(this.settings.indexPage);
    }

    try {
      validatePageName(name);
    } catch (e: any) {
      return this.flashNotification(e.message, "error");
    }

    if (newWindow) {
      const win = window.open(`${location.origin}/${name}`, "_blank");
      if (win) {
        win.focus();
      }
      return;
    }
    await this.pageNavigator!.navigate(name, pos, replaceState);
  }

  async loadPage(pageName: string): Promise<boolean> {
    const loadingDifferentPage = pageName !== this.currentPage;
    const editorView = this.editorView;
    const previousPage = this.currentPage;

    // Persist current page state and nicely close page
    if (previousPage) {
      this.openPages.saveState(previousPage);
      this.space.unwatchPage(previousPage);
      if (previousPage !== pageName) {
        await this.save(true);
      }
    }

    this.ui.viewDispatch({
      type: "page-loading",
      name: pageName,
    });

    // Fetch next page to open
    let doc;
    try {
      doc = await this.space.readPage(pageName);
      if (doc.meta.contentType.startsWith("text/html")) {
        throw new Error("Got HTML page, not markdown");
      }
    } catch (e: any) {
      if (e.message.includes("Not found")) {
        // Not found, new page
        console.log("Page doesn't exist, creating new page:", pageName);
        doc = {
          text: "",
          meta: { name: pageName, lastModified: 0, perm: "rw" } as PageMeta,
        };
      } else {
        console.error("Could not load page", pageName, e);
        doc = {
          text: `**ERROR**: ${e.message}`,
          meta: { name: pageName, lastModified: 0, perm: "ro" } as PageMeta,
        };
      }
    }

    const editorState = createEditorState(
      this,
      pageName,
      doc.text,
      doc.meta.perm === "ro",
    );
    editorView.setState(editorState);
    if (editorView.contentDOM) {
      this.tweakEditorDOM(editorView.contentDOM);
    }
    const stateRestored = this.openPages.restoreState(pageName);
    this.space.watchPage(pageName);

    this.ui.viewDispatch({
      type: "page-loaded",
      meta: doc.meta,
    });

    // Note: these events are dispatched asynchronously deliberately (not waiting for results)
    if (loadingDifferentPage) {
      this.eventHook.dispatchEvent("editor:pageLoaded", pageName, previousPage)
        .catch(
          console.error,
        );
    } else {
      this.eventHook.dispatchEvent("editor:pageReloaded", pageName).catch(
        console.error,
      );
    }

    return stateRestored;
  }

  tweakEditorDOM(contentDOM: HTMLElement) {
    contentDOM.spellcheck = true;
    contentDOM.setAttribute("autocorrect", "on");
    contentDOM.setAttribute("autocapitalize", "on");
  }

  async loadCustomStyles() {
    if (this.settings.customStyles) {
      const accumulatedCSS: string[] = [];
      let customStylePages = this.settings.customStyles;
      if (!Array.isArray(customStylePages)) {
        customStylePages = [customStylePages];
      }
      for (const customStylesPage of customStylePages) {
        try {
          const { text: stylesText } = await this.space.readPage(
            cleanPageRef(customStylesPage),
          );
          const cssBlockRegex = /```css([^`]+)```/;
          const match = cssBlockRegex.exec(stylesText);
          if (!match) {
            return;
          }
          accumulatedCSS.push(match[1]);
        } catch (e: any) {
          console.error("Failed to load custom styles", e);
        }
      }
      document.getElementById("custom-styles")!.innerHTML = accumulatedCSS.join(
        "\n\n",
      );
    }
  }

  async runCommandByName(name: string) {
    const cmd = this.ui.viewState.commands.get(name);
    if (cmd) {
      await cmd.run();
    } else {
      throw new Error(`Command ${name} not found`);
    }
  }

  getCommandsByContext(
    state: AppViewState,
  ): Map<string, AppCommand> {
    const commands = new Map(state.commands);
    for (const [k, v] of state.commands.entries()) {
      if (
        v.command.contexts &&
        (!state.showCommandPaletteContext ||
          !v.command.contexts.includes(state.showCommandPaletteContext))
      ) {
        commands.delete(k);
      }
    }

    return commands;
  }

  getContext(): string | undefined {
    const state = this.editorView.state;
    const selection = state.selection.main;
    if (selection.empty) {
      return syntaxTree(state).resolveInner(selection.from).type.name;
    }
    return;
  }
}