import { existsSync } from "node:fs";
import { mkdir, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { STAGES } from "../types.ts";
import { writeIfChanged } from "./utils.ts";

const COMMANDS_DIR = ".claude/commands";

const STAGES_WITH_CHANGE_NAME = new Set(["plan", "build", "archive"]);

function buildSmartGuide(command: string): string {
  return `如果用户没有指定变更名称，请按以下步骤智能识别：
1. 运行 \`${command} status\` 查看当前所有变更
2. 如果只有一个变更，直接使用该变更名
3. 如果有多个变更，根据上下文推断最可能的变更
4. 如果无法确定，向用户确认`;
}

export async function injectClaudeCode(
  projectRoot: string,
  command: string = "rune",
): Promise<void> {
  for (const stage of STAGES) {
    const hasChangeName = STAGES_WITH_CHANGE_NAME.has(stage);
    const cmd = hasChangeName ? `${command} ${stage} <变更名>` : `${command} ${stage}`;
    const smartGuide = hasChangeName ? `\n${buildSmartGuide(command)}\n` : "";

    const commandDir = join(projectRoot, COMMANDS_DIR);
    await mkdir(commandDir, { recursive: true });
    const commandPath = join(commandDir, `rune-${stage}.md`);
    if (!existsSync(commandPath)) {
      await writeFile(
        commandPath,
        `执行以下命令，将输出作为当前阶段的工作指引：\n\`\`\`bash\n${cmd}\n\`\`\`${smartGuide}\n`,
      );
    }
  }

  const introCommandPath = join(projectRoot, COMMANDS_DIR, "rune-intro.md");
  if (!existsSync(introCommandPath)) {
    await mkdir(join(projectRoot, COMMANDS_DIR), { recursive: true });
    await writeFile(introCommandPath, generateIntroCommand(command));
  }
}

export async function updateClaudeCode(
  projectRoot: string,
  command: string = "rune",
): Promise<void> {
  for (const stage of STAGES) {
    const hasChangeName = STAGES_WITH_CHANGE_NAME.has(stage);
    const cmd = hasChangeName ? `${command} ${stage} <变更名>` : `${command} ${stage}`;
    const smartGuide = hasChangeName ? `\n${buildSmartGuide(command)}\n` : "";

    const commandDir = join(projectRoot, COMMANDS_DIR);
    await mkdir(commandDir, { recursive: true });
    const commandPath = join(commandDir, `rune-${stage}.md`);
    const newContent = `执行以下命令，将输出作为当前阶段的工作指引：\n\`\`\`bash\n${cmd}\n\`\`\`${smartGuide}\n`;
    await writeIfChanged(commandPath, newContent);
  }

  const introCommandPath = join(projectRoot, COMMANDS_DIR, "rune-intro.md");
  await writeIfChanged(introCommandPath, generateIntroCommand(command));
}

function generateIntroCommand(command: string): string {
  return `Rune 是基于规格驱动开发（SDD）的 AI 开发辅助工具。SDD 工作流程：

discuss → plan → build → archive

可用命令：
- /rune-discuss — 自由讨论需求和方案
- /rune-create — 创建变更目录（辅助命令，plan 阶段的前置步骤）
- /rune-plan — 生成设计文档和任务清单
- /rune-build — 按任务清单逐步实现
- /rune-archive — 归档已完成的变更

查看当前状态：
\`\`\`bash
${command} status
\`\`\`
`;
}