import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";

import { runAddTemplateFlow } from "../workflows/add-template-flow.ts";
import { runCommitFlow } from "../workflows/commit-flow.ts";
import { runListTemplatesFlow } from "../workflows/list-templates-flow.ts";
import { runRemoveTemplateFlow } from "../workflows/remove-template-flow.ts";

/** 支持的无参数模板管理快捷命令。 */
const SUBCOMMANDS = [
  {
    value: "add",
    label: "add",
    description: "Create a commit message template",
  },
  {
    value: "list",
    label: "list",
    description: "List templates and switch the active one",
  },
  {
    value: "remove",
    label: "remove",
    description: "Remove a user template",
  },
];

/** 把未知错误转换为稳定的用户提示。 */
function getErrorMessage(error: unknown): string {
  return error instanceof Error ? error.message : String(error);
}

/** 注册带会话内互斥保护的 /git-commit 命令。 */
export function registerGitCommitCommand(pi: ExtensionAPI): void {
  let running = false;

  pi.registerCommand("git-commit", {
    description: "Generate, review, and commit the current Git changes",

    /** 仅为无参数模板管理快捷命令提供首词补全。 */
    getArgumentCompletions: (prefix) => {
      if (prefix.includes(" ")) {
        return null;
      }
      const matched = SUBCOMMANDS.filter((item) => item.value.startsWith(prefix));
      return matched.length > 0 ? matched : null;
    },

    /** 执行 /git-commit 命令。 */
    handler: async (args, ctx) => {
      if (!ctx.hasUI) {
        console.error("[pi-ai-git-commit] /git-commit requires interactive TUI or RPC mode.");
        return;
      }
      if (running) {
        ctx.ui.notify("A /git-commit workflow is already running.", "warning");
        return;
      }

      running = true;
      try {
        const trimmed = args.trim();
        if (trimmed === "add") {
          await runAddTemplateFlow(pi, ctx);
          return;
        }
        if (trimmed === "list") {
          await runListTemplatesFlow(pi, ctx);
          return;
        }
        if (trimmed === "remove") {
          await runRemoveTemplateFlow(pi, ctx);
          return;
        }

        await ctx.waitForIdle();
        await runCommitFlow(pi, ctx, trimmed);
      } catch (error) {
        ctx.ui.setStatus("pi-ai-git-commit", undefined);
        ctx.ui.notify(getErrorMessage(error), "error");
      } finally {
        running = false;
      }
    },
  });
}