import * as vscode from "vscode";
import { fetchSdkSummary } from "./cline";
import { CoauthorStore } from "./store";
import { ThreadController } from "./threadController";
import { AttributionController } from "./attributionController";
import { ProposalController } from "./proposalController";
import { buildFingerprint } from "./anchorer";
import { VersionGuard } from "./versionGuard";
import { BaselineStore } from "./baselineStore";
import { GlobalSidecarStore } from "./globalSidecarStore";
import { SidecarRouter } from "./sidecarRouter";
import { DiffViewController } from "./diffViewController";
import { GitBaselineAdapter } from "./gitBaseline";
import { EditFlow } from "./editFlow";
import { LiveProgressUi } from "./liveProgressUi";
import { EditorProposalController } from "./editorProposalController";
import { isAuthorable, routeEdit } from "./workspacePath";
import { CoeditingRegistry } from "./coeditingRegistry";
import { ScmSurfaceController } from "./scmSurface";
import type MarkdownIt from "markdown-it";
import { cowritingMarkdownItPlugin, type AnnotationInputs } from "./previewAnnotations";

const CHANNEL_NAME = "Cowriting (Cline SDK)";

export interface CowritingApi {
  threadController: ThreadController;
  attributionController: AttributionController;
  proposalController: ProposalController;
  versionGuard: VersionGuard;
  diffViewController: DiffViewController;
  editFlow: EditFlow;
  sidecarRouter: SidecarRouter;
  liveProgressUi: LiveProgressUi;
  editorProposalController: EditorProposalController;
  coeditingRegistry: CoeditingRegistry;
  scmSurfaceController: ScmSurfaceController;
  /** Task 7 test seam: the REAL production `inputsFor`, so E2E exercises the
   *  actual registry/diffView/attribution/proposals/config wiring (not a
   *  hand-rolled reimplementation of it). */
  previewAnnotationHost: { inputsFor(env: unknown): AnnotationInputs | undefined };
  /** Task 7 (D3/D21): the markdown-it plugin factory VS Code's built-in preview
   *  loads via `markdown.markdownItPlugins` (package.json). */
  extendMarkdownIt: (md: unknown) => unknown;
}

export function activate(context: vscode.ExtensionContext): CowritingApi | undefined {
  // --- POC command (Feature #2), unchanged ---
  const output = vscode.window.createOutputChannel(CHANNEL_NAME);
  context.subscriptions.push(output);

  // #60: shared live-progress UI (notification activity line + "Cowriting: Claude"
  // OutputChannel) for both Ask-Claude entry points.
  const liveProgressUi = new LiveProgressUi();
  context.subscriptions.push(liveProgressUi);
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.showClineSdkInfo", async () => {
      try {
        const summary = await fetchSdkSummary();
        output.clear();
        output.appendLine(`@cline/sdk version: ${summary.version}`);
        output.appendLine(`Builtin tools (${summary.tools.length}):`);
        for (const tool of summary.tools) output.appendLine(`  • ${tool.id} — ${tool.description}`);
        output.show(true);
        await vscode.window.showInformationMessage(
          `Cline SDK ${summary.version} loaded — ${summary.tools.length} builtin tools. See the "${CHANNEL_NAME}" output channel.`,
        );
      } catch (err) {
        const message = err instanceof Error ? err.message : String(err);
        output.appendLine(`Failed to drive @cline/sdk: ${message}`);
        output.show(true);
        await vscode.window.showErrorMessage(`Cowriting: failed to load @cline/sdk — ${message}`);
      }
    }),
  );

  // --- PUC-7 (native-surfaces migration): the INV-10 opt-in gate ---
  // Every later native surface (SCM/QuickDiff, comments, preview annotations,
  // edit commands, decorations) checks isCoediting before attaching. Persisted
  // in workspaceState so a reload restores the set.
  const coeditingRegistry = new CoeditingRegistry(context.workspaceState);
  context.subscriptions.push(coeditingRegistry);
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.coeditDocument", () => {
      const ed = vscode.window.activeTextEditor;
      if (!ed || ed.document.languageId !== "markdown" || !isAuthorable(ed.document.uri.scheme)) {
        void vscode.window.showWarningMessage("Cowriting: open a Markdown document to coedit it.");
        return;
      }
      coeditingRegistry.enter(ed.document.uri);
      coeditingRegistry.syncContext(ed);
    }),
    vscode.commands.registerCommand("cowriting.stopCoediting", () => {
      const ed = vscode.window.activeTextEditor;
      if (!ed) return;
      coeditingRegistry.exit(ed.document.uri);
      coeditingRegistry.syncContext(ed);
    }),
    vscode.window.onDidChangeActiveTextEditor((ed) => coeditingRegistry.syncContext(ed)),
  );
  coeditingRegistry.syncContext(vscode.window.activeTextEditor);

  // --- Baseline router (native-surfaces migration, spec §6.4, INV-7) — workspace-
  // INDEPENDENT --- The two-pane vscode.diff VIEW was removed in #34 (F10's
  // rendered preview is the single review surface); only the baseline data
  // layer survives, consumed by F7/F10. It tracks a baseline for ANY diffable
  // doc (file or untitled), so it is constructed regardless of whether a folder
  // is open. A SNAPSHOT baseline lives in VS Code's per-extension GLOBAL
  // storage (always present), never the repo (INV-19); a git-tracked doc's HEAD
  // baseline is never persisted (INV-7). Baselines are established only for
  // documents the CoeditingRegistry has entered — see the registry wiring
  // inside DiffViewController's constructor.
  const gitBaseline = new GitBaselineAdapter();
  context.subscriptions.push(gitBaseline);
  const baselineStorageDir = context.globalStorageUri?.fsPath;
  const baselineStore = baselineStorageDir ? new BaselineStore(baselineStorageDir) : null;
  const diffViewController = new DiffViewController(baselineStore, gitBaseline, coeditingRegistry);
  context.subscriptions.push(diffViewController);

  // Task 1 hook: expose the resolved baseline mode ("head"/"snapshot") to the
  // registry's context-key sync, and re-sync `cowriting.baselineMode` whenever
  // a baseline is (re)captured (entry, head-refresh, pin) — the "Mark Changes
  // as Reviewed" menu entry (snapshot-only, Task 3) is gated on that key.
  coeditingRegistry.baselineModeOf = (uri) => diffViewController.modeOf(uri.toString());
  context.subscriptions.push(
    diffViewController.onDidChangeBaseline(() => coeditingRegistry.syncContext(vscode.window.activeTextEditor)),
  );

  // --- Task 3: the native diff surface (spec §6.4/§5, INV-13) — QuickDiff
  // gutter bars, the cowriting-baseline: content provider, "Review Changes",
  // and the status-bar change count. Constructed after diffViewController
  // (consumes getBaseline/modeOf/onDidChangeBaseline) and the registry
  // (consumes isCoediting/onDidChange), gated on INV-10. ---
  const scmSurfaceController = new ScmSurfaceController(coeditingRegistry, diffViewController);
  context.subscriptions.push(scmSurfaceController);

  // F8: the out-of-workspace/untitled authoring sidecar — same GLOBAL storage
  // home as the F6 baseline, keyed by sha256(uri) (INV-19/24). Constructed
  // workspace-independently; the router falls back to it for any non-in-folder
  // doc. When globalStorageUri is unavailable, file writes throw (authoring
  // degrades to errors-on-write, the F6-equivalent edge) but untitled in-memory
  // still works — PUC-5.
  const globalSidecarStore = new GlobalSidecarStore(baselineStorageDir ?? "");

  // --- F8: authoring on ANY document (in-folder, out-of-folder, untitled) ---
  // The router routes per-document: in-workspace file: → the committable repo
  // `.threads/` sidecar (CoauthorStore, INV-2); out-of-folder file: + untitled:
  // → the global-storage sidecar (GlobalSidecarStore). Constructed even with NO
  // folder open (everything then routes global) — the F6 #19 precedent, now
  // extended to authoring (F2 threads, F3 attribution, F4 propose/accept).
  const root = vscode.workspace.workspaceFolders?.[0]?.uri.fsPath;
  const coauthorStore = root ? new CoauthorStore(root) : null;
  const sidecarRouter = new SidecarRouter(coauthorStore, globalSidecarStore, root);
  // F5 (INV-16): one shared guard — newer-major sidecars are read-only, one
  // warning per doc across the three co-owning controllers.
  const versionGuard = new VersionGuard(sidecarRouter);

  // --- F3: live attribution (Feature #6) ---
  const attributionController = new AttributionController(sidecarRouter, root, versionGuard, coeditingRegistry);
  context.subscriptions.push(attributionController);

  // --- F4: propose/accept (Feature #12) ---
  const proposalController = new ProposalController(
    sidecarRouter,
    attributionController,
    root,
    versionGuard,
    coeditingRegistry,
  );
  context.subscriptions.push(proposalController);

  // --- F11/F12 (native-surfaces migration, spec §6.10): the edit flow — the
  // `cowriting.editDocument` command, the instruction-prompt/progress-wrapped
  // "ask Claude" gesture (INV-10 gate), and the turn→proposal(s) cut
  // (`runEditAndPropose`, INV-39/40). Constructed BEFORE the thread controller,
  // which consumes it too (Task 6: the comment-loop's "make this edit" offer
  // calls runEditAndPropose). ---
  const editFlow = new EditFlow(proposalController);
  context.subscriptions.push(editFlow);

  // --- F2/F10 (Task 6, D19/D10/D8): comments-first ask + the comment→reply→
  // offer→proposal loop. Consumes editFlow (offer → pending proposals) and
  // liveProgressUi (the shared "asking Claude…" notification + output channel). ---
  const threadController = new ThreadController(sidecarRouter, root, versionGuard, coeditingRegistry, editFlow, liveProgressUi);
  context.subscriptions.push(threadController);

  // --- F12 (#64): the editor surface — optimistic-apply proposals into the buffer,
  // decorate the diff, and provide Accept ▾/Reject ▾ CodeLens (INV-48/49/52/53). ---
  const editorProposalController = new EditorProposalController(
    proposalController,
    diffViewController,
    attributionController,
    coeditingRegistry,
  );
  context.subscriptions.push(editorProposalController);

  // #46 (INV-42): accept every pending proposal on the active doc in one gesture
  // (also reachable from the top-of-file "Keep all (N)" CodeLens, Task 8 PUC-2).
  // Reuses the batched F4 seam + reports applied-vs-skipped, routing directly to
  // ProposalController (native-surfaces migration: no preview-controller
  // indirection).
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.acceptAllProposals", async () => {
      const doc = vscode.window.activeTextEditor?.document;
      if (!doc || doc.languageId !== "markdown") {
        void vscode.window.showWarningMessage("Cowriting: open a Markdown document to accept its proposals.");
        return;
      }
      const { applied, skipped } = await proposalController.acceptAllProposals(doc);
      if (applied === 0 && skipped === 0) return;
      const skipNote = skipped > 0 ? `, ${skipped} skipped (target text changed — undo or reject)` : "";
      void vscode.window.showInformationMessage(
        `Cowriting: accepted ${applied} proposal${applied === 1 ? "" : "s"}${skipNote}.`,
      );
    }),
  );

  // #64 (INV-53): reject every pending proposal on the active doc in one gesture
  // (native-surfaces migration: routes directly to ProposalController).
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.rejectAllProposals", async () => {
      const doc = vscode.window.activeTextEditor?.document;
      if (!doc || doc.languageId !== "markdown") {
        void vscode.window.showWarningMessage("Cowriting: open a Markdown document to reject its proposals.");
        return;
      }
      const { reverted } = await proposalController.rejectAll(doc);
      if (reverted > 0) {
        void vscode.window.showInformationMessage(
          `Cowriting: rejected ${reverted} proposal${reverted === 1 ? "" : "s"}.`,
        );
      }
    }),
  );

  // NOTE (native-surfaces migration, INV-7/INV-18 retirement): the shipped
  // machine-landing baseline advance (#48) — wiring
  // attributionController.onDidApplyAgentEdit → diffViewController.advance —
  // was removed here. A landed Claude edit now stays a visible change-since-
  // baseline until the file is committed (head mode) or reviewed via
  // "Mark Changes as Reviewed" (snapshot mode).

  // One SHARED sidecar watcher for both controllers; self-writes are suppressed
  // centrally in the repo store (only repo `.threads/` sidecars are watched —
  // global artifacts live outside the workspace). Harmless when no folder is open.
  const watcher = vscode.workspace.createFileSystemWatcher("**/.threads/**/*.json");
  const onSidecar = (uri: vscode.Uri) => {
    if (sidecarRouter.consumeSelfWrite(uri.fsPath)) return;
    threadController.handleExternalSidecarChange(uri);
    attributionController.handleExternalSidecarChange(uri);
    proposalController.handleExternalSidecarChange(uri);
  };
  watcher.onDidChange(onSidecar);
  watcher.onDidCreate(onSidecar);
  context.subscriptions.push(watcher);

  // The seam as a command (INV-9): the only machine-edit ingress, hidden from
  // the palette — for the host E2E harness and future SDK turn plumbing.
  context.subscriptions.push(
    vscode.commands.registerCommand(
      "cowriting.applyAgentEdit",
      (args: {
        uri: string; start: number; end: number; newText: string;
        model?: string; sessionId?: string; turnId?: string;
      }) => {
        const doc = vscode.workspace.textDocuments.find((d) => d.uri.toString() === args.uri);
        if (!doc) return Promise.resolve(false);
        const range = new vscode.Range(doc.positionAt(args.start), doc.positionAt(args.end));
        const provenance = {
          kind: "agent" as const,
          id: "claude",
          agent: { sdk: "@cline/sdk", model: args.model ?? "sonnet", sessionId: args.sessionId ?? "" },
        };
        return attributionController.applyAgentEdit(doc, range, args.newText, provenance, { turnId: args.turnId });
      },
    ),
  );

  // The propose ingress as a command (spec §6.4): records a pending proposal,
  // NEVER touches the document (INV-10) — for the host E2E harness.
  context.subscriptions.push(
    vscode.commands.registerCommand(
      "cowriting.proposeAgentEdit",
      (args: {
        uri: string; start: number; end: number; newText: string;
        model?: string; sessionId?: string; turnId?: string; instruction?: string;
      }) => {
        const doc = vscode.workspace.textDocuments.find((d) => d.uri.toString() === args.uri);
        if (!doc) return Promise.resolve(undefined);
        const fp = buildFingerprint(doc.getText(), { start: args.start, end: args.end });
        const provenance = {
          kind: "agent" as const,
          id: "claude",
          agent: { sdk: "@cline/sdk", model: args.model ?? "sonnet", sessionId: args.sessionId ?? "" },
        };
        return proposalController.propose(doc, fp, args.newText, provenance, {
          turnId: args.turnId,
          instruction: args.instruction,
        });
      },
    ),
  );

  // Task 6 (D19): the comments-first ask replaces the old inline turn
  // plumbing here — the ask now IS a comment. threadController.askClaude()
  // opens a focused comment box on the current selection (or, with no
  // selection, a top-anchored whole-document thread); the comment→reply→
  // offer→proposal loop (ThreadController.respondInThread/makeThreadEdit)
  // takes it from there. Kept as its own command (rather than folded into
  // cowriting.edit) for the host E2E harness and the internal seams.
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.editSelection", async () => {
      await threadController.askClaude();
    }),
  );

  // Code-review fix (Finding 1, session native-surfaces-exec): `cowriting.editDocument`
  // used to delegate to `EditFlow.askClaude(doc, {kind:"document"})`, which prompted via
  // `askEditInstruction` — a rejecting stub after Task 6 sunset the input webview
  // (spec §6.10; both `askClaude`/`askEditInstruction` were deleted from EditFlow in
  // Task 8 once their only caller, the review webview, died too). Reached with no
  // selection (the common case for `cowriting.edit`), that was a SILENT dead end: the
  // reject fired before EditFlow.askClaude's own try/catch and was `void`'d, so no
  // toast, no thread, nothing. This command now resolves
  // its target document exactly as before (a tab's clicked URI, falling back to the
  // active editor), focuses it, and hands off to the SAME comments-first ask as
  // `cowriting.editSelection` — `ThreadController.askClaude()` top-anchors a
  // whole-document ask when the (now-focused) editor's selection is empty (D19). Kept
  // registered + hidden from the palette for the host E2E harness and #42's
  // tab-targeting behavior; `EditFlow.runEditAndPropose` (untouched) stays the E2E seam
  // for driving a turn without the native comment UI — see f12Reach.test.ts /
  // f11Toolbar.test.ts / f12Accept.test.ts / f12Review.test.ts.
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.editDocument", async (uri?: vscode.Uri) => {
      const doc = uri
        ? vscode.workspace.textDocuments.find((d) => d.uri.toString() === uri.toString()) ??
          (await vscode.workspace.openTextDocument(uri))
        : vscode.window.activeTextEditor?.document;
      if (!doc || doc.languageId !== "markdown") {
        void vscode.window.showWarningMessage("Cowriting: open a Markdown document to ask Claude to edit it.");
        return;
      }
      if (vscode.window.activeTextEditor?.document.uri.toString() !== doc.uri.toString()) {
        await vscode.window.showTextDocument(doc);
      }
      await threadController.askClaude();
    }),
  );

  // The single user-facing "Ask Claude to Edit" gesture (one command, one
  // keybinding, one menu entry). It routes to the selection flow (editSelection)
  // or the whole-document flow (editDocument) by selection/context — see
  // routeEdit. Both underlying commands now end at ThreadController.askClaude()
  // (comments-first ask, D19); they stay registered for the host E2E harness and
  // the internal seams, but are hidden from the palette.
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.edit", async (uri?: vscode.Uri) => {
      const editor = vscode.window.activeTextEditor;
      const route = routeEdit({
        hasUri: !!uri,
        uriMatchesActiveEditor: !!uri && editor?.document.uri.toString() === uri.toString(),
        hasActiveEditor: !!editor,
        selectionEmpty: editor?.selection.isEmpty ?? true,
      });
      if (route === "selection") {
        await vscode.commands.executeCommand("cowriting.editSelection");
      } else {
        await vscode.commands.executeCommand("cowriting.editDocument", uri);
      }
    }),
  );

  // Task 8 (native-surfaces migration, spec §6.10): the minimal gateway replacing
  // the sunset review-webview's #41 right-click entries. Resolves the clicked
  // doc (or falls back to the active editor, mirroring editDocument/#41), enters
  // coediting if not already (so a fresh doc gets a baseline to review against —
  // no-op if already entered or not authorable), then hands off to VS Code's
  // OWN "Open Preview to the Side" — the built-in preview IS the review surface
  // now (Task 7's annotations render inside it).
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.openReviewPreview", async (uri?: vscode.Uri) => {
      const doc = uri
        ? vscode.workspace.textDocuments.find((d) => d.uri.toString() === uri.toString()) ??
          (await vscode.workspace.openTextDocument(uri))
        : vscode.window.activeTextEditor?.document;
      if (!doc || doc.languageId !== "markdown") {
        void vscode.window.showWarningMessage("Cowriting: open a Markdown document to review it.");
        return;
      }
      if (vscode.window.activeTextEditor?.document.uri.toString() !== doc.uri.toString()) {
        await vscode.window.showTextDocument(doc);
      }
      if (!coeditingRegistry.isCoediting(doc.uri) && isAuthorable(doc.uri.scheme)) {
        await vscode.commands.executeCommand("cowriting.coeditDocument");
      }
      await vscode.commands.executeCommand("markdown.showPreviewToSide", doc.uri);
    }),
  );

  // Render threads + attributions for already-open editors, and on future opens.
  // INV-10: gated on the registry too — belt-and-suspenders with the per-controller
  // gates (renderAll/loadAll already early-return), but keeps the intent explicit
  // at the call site and avoids the no-op calls for a non-entered doc.
  const renderIfOpen = (doc: vscode.TextDocument) => {
    if (isAuthorable(doc.uri.scheme) && coeditingRegistry.isCoediting(doc.uri)) {
      // Finding 3 (final whole-branch review): DiffViewController only
      // establishes a baseline on the registry's enter TRANSITION and, at
      // startup, for documents already open. A doc that is a PERSISTED
      // coediting member but wasn't open yet at either of those moments (e.g.
      // lazily restored after a window reload) reaches this handler with no
      // baseline/mode — establish it now so QuickDiff/Review-Changes/Mark-
      // Reviewed never see a silent empty-baseline gap.
      if (diffViewController.modeOf(doc.uri.toString()) === undefined) void diffViewController.establish(doc);
      threadController.renderAll(doc);
      attributionController.loadAll(doc);
      proposalController.renderAll(doc);
    }
  };
  vscode.workspace.textDocuments.forEach(renderIfOpen);
  context.subscriptions.push(vscode.workspace.onDidOpenTextDocument(renderIfOpen));

  // --- Task 7 (D3/D21, PUC-3): annotations in the BUILT-IN Markdown preview ---
  // `env.currentDocument` (VS Code's markdown-it render env) is an OBSERVED
  // preview-engine behavior, not a documented contract, so `lastCoeditedUri`
  // is the fallback that keeps single-doc correctness when it's absent — the
  // last editor that WAS coediting when it lost focus (e.g. focus moved to the
  // preview pane itself) stays the annotation target until a different
  // coedited doc becomes active.
  let lastCoeditedUri: string | undefined;
  const trackLastCoedited = (ed: vscode.TextEditor | undefined) => {
    if (ed && coeditingRegistry.isCoediting(ed.document.uri)) lastCoeditedUri = ed.document.uri.toString();
  };
  trackLastCoedited(vscode.window.activeTextEditor);
  context.subscriptions.push(
    vscode.window.onDidChangeActiveTextEditor(trackLastCoedited),
    // The active editor doesn't itself change when `cowriting.coeditDocument`
    // enters IT into coediting — re-check on every gate change too, so the
    // very first render after entering already has an annotation target.
    coeditingRegistry.onDidChange(() => trackLastCoedited(vscode.window.activeTextEditor)),
  );

  const previewAnnotationHost = {
    inputsFor(env: unknown): AnnotationInputs | undefined {
      const envUri = (env as { currentDocument?: { toString(): string } } | undefined)?.currentDocument?.toString();
      // Finding 1 (final whole-branch review): the `lastCoeditedUri` fallback
      // is for an ABSENT env only (env.currentDocument didn't resolve) — a
      // present envUri is authoritative for the doc actually being previewed
      // and must never fall back to a different (or since-exited) document's
      // inputs. Either way, the winning key must currently be a coediting
      // member (INV-10) — an exited doc's stale `lastCoeditedUri` fails this
      // check too, closing the "preview stays annotated after stopCoediting"
      // gap.
      const key = envUri === undefined ? lastCoeditedUri : envUri;
      if (!key || !coeditingRegistry.list().includes(key)) return undefined;
      const doc = vscode.workspace.textDocuments.find((d) => d.uri.toString() === key);
      if (!doc) return undefined;
      const baseline = diffViewController.getBaseline(key);
      return {
        baselineText: baseline?.text,
        baselineReason: baseline?.reason,
        spans: attributionController.spansFor(doc),
        proposals: proposalController.listProposals(doc),
        enabled: vscode.workspace.getConfiguration("cowriting").get<boolean>("annotations", true),
      };
    },
  };

  // Toggle: flips `cowriting.annotations` + refreshes the built-in preview
  // (VS Code re-invokes extendMarkdownIt's plugin on the next render — no
  // extension-side re-render call exists beyond the standard refresh command).
  context.subscriptions.push(
    vscode.commands.registerCommand("cowriting.toggleAnnotations", async () => {
      const config = vscode.workspace.getConfiguration("cowriting");
      const current = config.get<boolean>("annotations", true);
      await config.update("annotations", !current, vscode.ConfigurationTarget.Global);
      await vscode.commands.executeCommand("markdown.preview.refresh");
    }),
  );

  return {
    threadController,
    attributionController,
    proposalController,
    versionGuard,
    diffViewController,
    editFlow,
    sidecarRouter,
    liveProgressUi,
    editorProposalController,
    coeditingRegistry,
    scmSurfaceController,
    previewAnnotationHost,
    extendMarkdownIt: (md: unknown) => cowritingMarkdownItPlugin(md as MarkdownIt, previewAnnotationHost),
  };
}

export function deactivate(): void {
  // Disposables registered on the context handle cleanup.
}