package internal

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"gopkg.in/yaml.v3"
)

// Config YAML 配置结构（嵌套：分组 → 工作空间）
type Config struct {
	Groups []GroupConfig `yaml:"groups"`
}

type GroupConfig struct {
	Label string            `yaml:"label"`
	Desc  string            `yaml:"desc"`
	Base  int               `yaml:"base"`
	Items []WorkspaceConfig `yaml:"items"`
}

type WorkspaceConfig struct {
	Title  string `yaml:"title"`
	Prompt string `yaml:"prompt"`
	Tech   string `yaml:"tech"`
	Deploy string `yaml:"deploy"`
	Dir    string `yaml:"dir"`
}

// LoadConfig 加载配置文件
// 优先级: ~/.u-tabs/config.yaml > exe同目录/config.yaml
func LoadConfig() (*Config, error) {
	// 1. 尝试用户目录
	userDir, err := os.UserHomeDir()
	if err == nil {
		userCfg := filepath.Join(userDir, ".u-tabs", "config.yaml")
		if cfg, err := loadConfigFile(userCfg); err == nil {
			return cfg, nil
		}
	}

	// 2. 尝试 exe 同目录
	exePath, err := os.Executable()
	if err == nil {
		exeDir := filepath.Dir(exePath)
		exeCfg := filepath.Join(exeDir, "config.yaml")
		if cfg, err := loadConfigFile(exeCfg); err == nil {
			return cfg, nil
		}
	}

	return nil, fmt.Errorf("未找到配置文件")
}

func loadConfigFile(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}
	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, err
	}
	return &cfg, nil
}

// ToInternal 将 YAML 配置转换为内部数据结构
// 自动生成: index(全局索引), n(编号=base+序号), group(继承父级)
func (c *Config) ToInternal() ([]Group, []Workspace) {
	groups := make([]Group, len(c.Groups))
	var allWorkspaces []Workspace
	globalIdx := 0

	for gi, g := range c.Groups {
		groups[gi] = Group{Label: g.Label, Desc: g.Desc}

		for wi, w := range g.Items {
			allWorkspaces = append(allWorkspaces, Workspace{
				Index:  globalIdx,
				N:      g.Base + wi,
				Title:  w.Title,
				Prompt: w.Prompt,
				Tech:   w.Tech,
				Deploy: w.Deploy,
				Dir:    expandHome(w.Dir),
				Group:  g.Label,
			})
			globalIdx++
		}
	}
	return groups, allWorkspaces
}

// expandHome 将 ~ 展开为用户主目录
func expandHome(dir string) string {
	if strings.HasPrefix(dir, "~") {
		home, _ := os.UserHomeDir()
		return strings.Replace(dir, "~", home, 1)
	}
	return dir
}