/* Copyright 2026 Marimo. All rights reserved. */
import type { Extension } from "@codemirror/state";
import { EditorView } from "@codemirror/view";
import { focusPackagesInput } from "@/components/editor/chrome/panels/packages-utils";
import { chromeAtom } from "@/components/editor/chrome/state";
import { Kbd } from "@/components/ui/kbd";
import { userConfigAtom } from "@/core/config/config";
import { getRequestClient } from "@/core/network/requests";
import { store } from "@/core/state/jotai";
import { toast } from "../../../components/ui/use-toast";

interface ReplaceCommand {
  match: string;
  onMatch: () => void;
  title: React.ReactNode;
  description: React.ReactNode;
}

const COMMON_MAGIC_COMMANDS = [
  // Line magics
  "%alias",
  "%cd",
  "%clear",
  "%debug",
  "%env",
  "%load",
  "%load_ext",
  "%lsmagic",
  "%matplotlib",
  "%pwd",
  "%who_ls",
  "%system",
  // Cell magics
  "%%time",
  "%%timeit",
  "%%writefile",
  "%%capture",
  "%%html",
  "%%latex",
];

let toastResponse: ReturnType<typeof toast>;

export function jupyterHelpExtension(): Extension {
  // Function to update the module reload mode
  // Updates local config and saves to server
  const handleUpdateModuleReload = async (mode: "lazy" | "autorun" | "off") => {
    const config = store.get(userConfigAtom);
    const { saveUserConfig } = getRequestClient();
    // Send only the changed portion to avoid overwriting other config values
    await saveUserConfig({ config: { runtime: { auto_reload: mode } } }).then(
      () =>
        // Update local state with merged config
        store.set(userConfigAtom, {
          ...config,
          runtime: { ...config.runtime, auto_reload: mode },
        }),
    );
  };

  const commands: ReplaceCommand[] = [
    // Package installation
    {
      match: "!pip install",
      onMatch: () => {
        store.set(chromeAtom, (prev) => ({
          ...prev,
          isSidebarOpen: true,
          selectedPanel: "packages",
        }));

        focusPackagesInput();
      },
      title: "Package Installation",
      description: (
        <>
          The package manager sidebar has been opened.
          <br />
          Install packages directly from there instead.
        </>
      ),
    },
    {
      match: "!uv pip install",
      onMatch: () => {
        store.set(chromeAtom, (prev) => ({
          ...prev,
          isSidebarOpen: true,
          selectedPanel: "packages",
        }));

        focusPackagesInput();
      },
      title: "Package Installation",
      description: (
        <>
          The package manager sidebar has been opened.
          <br />
          Install packages directly from there instead.
        </>
      ),
    },
    {
      match: "!uv add",
      onMatch: () => {
        store.set(chromeAtom, (prev) => ({
          ...prev,
          isSidebarOpen: true,
          selectedPanel: "packages",
        }));

        focusPackagesInput();
      },
      title: "Package Installation",
      description: (
        <>
          The package manager sidebar has been opened.
          <br />
          Install packages directly from there instead.
        </>
      ),
    },

    // Module reload
    {
      match: "%autoreload 2",
      onMatch: async () => {
        await handleUpdateModuleReload("autorun");
      },
      title: "Module reload",
      description: (
        <>
          Module reload mode set to <b>autorun</b> - module changes will re-run
          the cells that import them.
        </>
      ),
    },
    {
      match: "%autoreload 1",
      onMatch: async () => {
        await handleUpdateModuleReload("lazy");
      },
      title: "Module reload",
      description: (
        <>
          Module reload mode set to <b>lazy</b> - module changes will mark the
          cells that import them as stale.
        </>
      ),
    },
    {
      match: "%autoreload 0",
      onMatch: async () => {
        await handleUpdateModuleReload("off");
      },
      title: "Module reload",
      description: (
        <>Module reload disabled - module changes will not be detected.</>
      ),
    },

    // Shell commands
    {
      match: "!ls",
      onMatch: () => {
        // noop
      },
      title: "Listing files",
      description: (
        <>
          Shell commands are not directly supported.
          <br />
          Use <code>import subprocess; subprocess.run(['ls'])</code> instead.
        </>
      ),
    },

    // Common magic commands
    ...COMMON_MAGIC_COMMANDS.map((cmd) => ({
      match: cmd,
      onMatch: () => {
        // noop
      },
      title: <Kbd className="inline">{cmd}</Kbd>,
      description: (
        <>
          Magic commands are not supported in marimo. Read more about
          replacements in the{" "}
          <a
            href="https://docs.marimo.io/guides/coming_from/jupyter/#adapting-to-the-absence-of-magic-commands"
            target="_blank"
            className="text-link underline cursor-pointer"
            rel="noopener noreferrer"
          >
            documentation
          </a>
          .
        </>
      ),
    })),
  ];

  const commandMap = new Map(commands.map((cmd) => [cmd.match, cmd]));

  return EditorView.updateListener.of((update) => {
    if (update.docChanged) {
      const cursor = update.state.selection.main;
      // Get text from the start of the line to the cursor
      const doc = update.state.doc;
      const line = doc.lineAt(cursor.head);
      const text = doc.sliceString(line.from, cursor.anchor).trim();

      const cmd = commandMap.get(text);
      if (cmd) {
        // Execute the command
        cmd.onMatch();

        // Show toast
        if (toastResponse) {
          toastResponse.upsert({
            title: cmd.title,
            description: cmd.description,
          });
        } else {
          toastResponse = toast({
            title: cmd.title,
            description: cmd.description,
          });
        }
      }
    }
  });
}