import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
import * as fs from "node:fs";
import * as path from "node:path";
import { parseFeaturesMd } from "../lib/features-parser.js";
import { runAgent } from "../lib/agents.js";
import { TO_FEATURES_MD_TASK } from "../lib/prompts.js";

export function registerToFeaturesMdCommand(pi: ExtensionAPI) {
  pi.registerCommand("hive:to-features-md", {
    description: "Convert .hive/ analysis into features.md",
    handler: async (_args, ctx) => {
      const hiveDir = path.join(ctx.cwd, ".hive");
      const mapPath = path.join(hiveDir, "codebase-map.json");
      const summaryPath = path.join(hiveDir, "summary.md");

      // Verify prerequisites
      if (!fs.existsSync(mapPath) || !fs.existsSync(summaryPath)) {
        const mapOk = fs.existsSync(mapPath);
        const sumOk = fs.existsSync(summaryPath);
        ctx.ui.notify(
          `.hive/ analysis not found or incomplete.\n\n  codebase-map.json: ${mapOk ? "✓" : "✗"}\n  summary.md: ${sumOk ? "✓" : "✗"}\n\nRun /hive:map-codebase first.`,
          "warning",
        );
        return;
      }

      // Check if features.md already exists
      const featuresPath = path.join(ctx.cwd, "features.md");
      if (fs.existsSync(featuresPath)) {
        const autoApprove = pi.getFlag("--auto-approve") as boolean;
        if (!autoApprove) {
          const ok = await ctx.ui.confirm(
            "features.md already exists",
            "Overwrite? (current will be backed up to features.md.backup)",
          );
          if (!ok) return;
        }
        fs.copyFileSync(featuresPath, path.join(ctx.cwd, "features.md.backup"));
      }

      ctx.ui.notify("Generating features from .hive/ analysis...", "info");
      ctx.ui.setStatus("hive", "Generating features...");

      // Planner agent reads .hive/ and generates features.md
      const result = await runAgent("planner", TO_FEATURES_MD_TASK, ctx.cwd);

      ctx.ui.setStatus("hive", undefined);

      if (result.exitCode !== 0) {
        ctx.ui.notify(`Feature generation failed: ${result.stderr || result.output}`, "error");
        return;
      }

      // Verify features.md was created/updated
      if (fs.existsSync(featuresPath)) {
        const content = fs.readFileSync(featuresPath, "utf-8");
        const features = parseFeaturesMd(content);
        ctx.ui.notify(
          `features.md created with ${features.length} features.\n\nNext steps:\n  /hive:worktree-split --count 3\n  /hive:run`,
          "info",
        );
      } else {
        ctx.ui.notify(
          "Planner completed but features.md was not written.\nTry /hive:spec instead (uses current session with write access).",
          "warning",
        );
      }
    },
  });
}