import type { ExtensionAPI, ToolInfo } from "@earendil-works/pi-coding-agent";
import { fileURLToPath } from "node:url";
import { homedir } from "node:os";
import * as fs from "node:fs";
import * as path from "node:path";

// Resolve the pi-coding-agent package directory
// Search in: project node_modules, then global mise node_modules
function findPkgDir(): string {
  // Try project node_modules first
  const projectPkg = path.join(process.cwd(), "node_modules", "@earendil-works", "pi-coding-agent");
  if (fs.existsSync(projectPkg)) return projectPkg;

  // Try global mise node_modules
  const home = homedir();
  const globalPkg = path.join(home, ".local", "share", "mise", "installs", "node", "*", "lib", "node_modules", "@earendil-works", "pi-coding-agent");
  const matches = fs.readdirSync(path.join(home, ".local", "share", "mise", "installs", "node")).filter((d) =>
    fs.existsSync(path.join(home, ".local", "share", "mise", "installs", "node", d)),
  );
  for (const version of matches) {
    const candidate = path.join(
      home,
      ".local",
      "share",
      "mise",
      "installs",
      "node",
      version,
      "lib",
      "node_modules",
      "@earendil-works",
      "pi-coding-agent",
    );
    if (fs.existsSync(candidate)) return candidate;
  }

  // Fallback: try the directory of the loaded module
  const extPath = fileURLToPath(import.meta.url);
  let dir = extPath;
  for (let i = 0; i < 20; i++) {
    const candidate = path.join(dir, "node_modules", "@earendil-works", "pi-coding-agent");
    if (fs.existsSync(candidate)) return candidate;
    const parent = path.dirname(dir);
    if (parent === dir) break;
    dir = parent;
  }

  throw new Error("Could not find @earendil-works/pi-coding-agent package");
}

const pkgDir = findPkgDir();
const exportHtmlModule = await import(path.join(pkgDir, "dist", "core", "export-html", "index.js"));
const { exportSessionToHtml } = exportHtmlModule;

export default function (pi: ExtensionAPI) {
  pi.registerCommand("clear", {
    description: "Export session to transcripts/ and start a new session",
    handler: async (_args, ctx) => {
      if (ctx.mode !== "tui") {
        ctx.ui.notify("clear requires interactive mode", "error");
        return;
      }

      // Prompt for transcript name
      const name = await ctx.ui.input("Clear & Export", "Transcript name (spaces become dashes)", {
        timeout: 60000,
      });
      if (!name || !name.trim()) {
        ctx.ui.notify("Clear & Export cancelled", "info");
        return;
      }

      // Sanitize: spaces → dashes, ensure .html extension
      const sanitizedName = name.trim().replace(/\s+/g, "-");
      const fileName = sanitizedName.endsWith(".html") ? sanitizedName : `${sanitizedName}.html`;

      // Build output path in transcripts/
      const transcriptsDir = path.join(ctx.cwd, "transcripts");
      const outputPath = path.join(transcriptsDir, fileName);

      // Ensure transcripts directory exists
      if (!fs.existsSync(transcriptsDir)) {
        fs.mkdirSync(transcriptsDir, { recursive: true });
      }

      // Get session file path
      const sessionFile = ctx.sessionManager.getSessionFile();
      if (!sessionFile) {
        ctx.ui.notify("No session to export", "error");
        return;
      }

      // Build state from in-memory data (not available in a separate pi process)
      const state = {
        systemPrompt: ctx.getSystemPrompt(),
        tools: pi.getAllTools(),
      };

      // Export session to HTML with full in-memory state
      await exportSessionToHtml(ctx.sessionManager, state, { outputPath });

      ctx.ui.notify(`Exported to: transcripts/${fileName}`, "info");

      // Start a new session
      const currentSessionFile = ctx.sessionManager.getSessionFile();
      const newResult = await ctx.newSession({
        parentSession: currentSessionFile,
        withSession: (replacementCtx) => {
          replacementCtx.ui.notify("Session cleared and exported", "info");
        },
      });

      if (newResult.cancelled) {
        ctx.ui.notify("New session cancelled", "info");
      }
    },
  });
}