import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { isToolCallEventType } from "@earendil-works/pi-coding-agent";
import { matchesKey, Key } from "@earendil-works/pi-tui";
import { resolve } from "node:path";
import { readFile, access } from "node:fs/promises";

import { addFile, clearFiles, getFiles, getFileCount, rebuildFromSession } from "./state.js";
import { FileViewer, BorderFrame } from "./viewer.js";

export default function (pi: ExtensionAPI) {
  pi.on("session_start", async (_event, ctx) => {
    rebuildFromSession(ctx.sessionManager);
  });

  pi.on("tool_call", async (event, ctx) => {
    if (isToolCallEventType("read", event)) {
      const path = resolve(ctx.cwd, event.input.path);
      addFile(path, Date.now());
      pi.appendEntry("reader-file", { path, readAt: Date.now() });
    }
  });

  pi.registerCommand("reader", {
    description: "Browse files pi has read",
    handler: async (args, ctx) => {
      if (args) {
        const path = resolve(ctx.cwd, args.trim());
        addFile(path, Date.now());
        pi.appendEntry("reader-file", { path, readAt: Date.now() });
      }

      if (getFileCount() === 0) {
        ctx.ui.notify("No files tracked yet", "warning");
        return;
      }

      const allFiles = Array.from(getFiles().values());
      const contentCache = new Map<string, string>();
      const files: typeof allFiles = [];

      await Promise.all(
        allFiles.map(async (file) => {
          try {
            await access(file.path);
            contentCache.set(file.path, await readFile(file.path, "utf-8"));
            files.push(file);
          } catch {}
        })
      );

      const selected = await ctx.ui.custom<string | null>(
        (tui, theme, _kb, done) => {
          const viewer = new FileViewer(files, ctx.cwd, contentCache, tui, theme);
          const framed = new BorderFrame(viewer, (text) => theme.fg("accent", text));

          return {
            render: (width: number) => framed.render(width),
            invalidate: () => framed.invalidate(),
            handleInput: (data: string) => {
              viewer.handleInput(data);
              tui.requestRender();
              if (matchesKey(data, Key.enter)) {
                done(viewer.getSelectedFile());
                return;
              }
              if (matchesKey(data, Key.escape)) {
                done(null);
              }
            },
          };
        },
        {
          overlay: true,
          overlayOptions: {
            anchor: "center",
            width: "90%",
            maxHeight: "90%",
            margin: 1,
          },
        },
      );

      if (selected) {
        pi.sendMessage({
          customType: "reader",
          content: `File: ${selected}\n\n${contentCache.get(selected) ?? ""}`,
          display: true,
        });
      }
    },
  });
}