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

import { setActiveTemplate } from "../config/update-config.ts";
import { tryResolveGitRepositoryRoot } from "../git/collect-changes.ts";
import { GitClient } from "../git/git-client.ts";
import { isValidTemplateName } from "../templates/load-template.ts";
import { saveUserTemplate, userTemplateExists } from "../templates/save-template.ts";

const CANCELLED_MESSAGE = "Cancelled. No template was saved.";

/**
 * 执行 /git-commit add 的模板创建工作流：
 * 输入名称、编辑内容、写入用户模板目录，并按需立即启用。
 */
export async function runAddTemplateFlow(
  pi: ExtensionAPI,
  ctx: ExtensionCommandContext,
): Promise<void> {
  const input = await ctx.ui.input("Template name (letters, digits, . _ -)");
  // Esc 取消输入不是失败，保持与提交工作流一致的普通提示。
  if (input === undefined) {
    ctx.ui.notify(CANCELLED_MESSAGE, "info");
    return;
  }
  const name = input.trim();

  if (!isValidTemplateName(name)) {
    throw new Error(
      `Template name "${name}" is invalid. Use letters, digits, dots, hyphens, or underscores, starting with a letter or digit.`,
    );
  }

  const exists = await userTemplateExists(name);
  let overwrite = false;
  if (exists) {
    overwrite = await ctx.ui.confirm(
      "Overwrite template",
      `Template "${name}" already exists in your templates directory. Overwrite it?`,
    );
    if (!overwrite) {
      ctx.ui.notify(CANCELLED_MESSAGE, "info");
      return;
    }
  }

  const content = await ctx.ui.editor(`Template content for "${name}"`);
  if (content === undefined || !content.trim()) {
    ctx.ui.notify(CANCELLED_MESSAGE, "info");
    return;
  }

  const path = await saveUserTemplate(name, content, { overwrite });

  const useNow = await ctx.ui.confirm(
    "Activate template",
    `Template "${name}" was saved. Use it for future generations?`,
  );
  if (useNow) {
    // 与 list 一致：项目配置存在时写项目层，否则写全局配置。
    const projectDir = await tryResolveGitRepositoryRoot(new GitClient(pi), ctx.cwd);
    const target = await setActiveTemplate(name, projectDir);
    const scopeText = target.scope === "project" ? "project configuration" : "global configuration";
    ctx.ui.notify(`Template "${name}" saved and activated in the ${scopeText}.\n${path}`, "info");
    return;
  }
  ctx.ui.notify(`Template "${name}" saved.\n${path}`, "info");
}