package main

import (
	"fmt"
	"os"
	"strings"

	"gopkg.in/yaml.v3"
)

// LoadAgent 从 .md 文件加载 agent 定义
// 搜索结果：项目目录 → 全局配置目录
func LoadAgent(name string) (*AgentDef, error) {
	path := SearchFile(name)
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("读取 agent 文件失败 (搜索路径: %s): %w", name, err)
	}

	content := string(data)
	frontmatter, body, err := parseFrontmatter(content)
	if err != nil {
		return nil, err
	}

	def := &AgentDef{SystemPrompt: strings.TrimSpace(body)}
	if err := yaml.Unmarshal([]byte(frontmatter), def); err != nil {
		return nil, fmt.Errorf("解析 frontmatter 失败: %w", err)
	}

	if def.Name == "" {
		return nil, fmt.Errorf("agent 定义缺少 name 字段")
	}

	// 注入能力边界目录到 system prompt
	def.SystemPrompt += BuildInjectPrompt(def.Tools)

	return def, nil
}

func parseFrontmatter(content string) (string, string, error) {
	lines := strings.Split(content, "\n")
	if len(lines) < 2 || strings.TrimSpace(lines[0]) != "---" {
		return "", content, nil
	}

	endIdx := -1
	for i := 1; i < len(lines); i++ {
		if strings.TrimSpace(lines[i]) == "---" {
			endIdx = i
			break
		}
	}
	if endIdx == -1 {
		return "", content, nil
	}

	frontmatter := strings.Join(lines[1:endIdx], "\n")
	body := strings.Join(lines[endIdx+1:], "\n")
	return frontmatter, body, nil
}

// LoadSkill 按名称加载 skill 知识内容
// 搜索结果：skills/<name>/SKILL.md → ~/.config/weather-cli/skills/<name>/SKILL.md
func LoadSkill(name string) (string, error) {
	relativePath := fmt.Sprintf("skills/%s/SKILL.md", name)
	path := SearchFile(relativePath)

	data, err := os.ReadFile(path)
	if err != nil {
		return "", fmt.Errorf("skill %q 未找到", name)
	}

	_, body, _ := parseFrontmatter(string(data))
	return strings.TrimSpace(body), nil
}