package execenv

import (
	"encoding/json"
	"os"
)

// Catalog 是管理员可编辑的白名单。不在白名单里的包不会自动安装。
type Catalog struct {
	MaxWheelBytes int64          `json:"maxWheelBytes"`
	Allow         []CatalogEntry `json:"allow"`
	Deny          []string       `json:"deny"`
}

// CatalogEntry 的 Spec 为空表示任意版本；非空时是给人类看的范围说明，
// 自动批准只看包名是否在列，版本冲突另由基础层锁判定。
type CatalogEntry struct {
	Name   string `json:"name"`
	Spec   string `json:"spec,omitempty"`
	Reason string `json:"reason,omitempty"`
}

// DefaultCatalog 是第一次创建环境根时落下的名单。之后以磁盘上的 catalog.json 为准。
func DefaultCatalog() Catalog {
	return Catalog{
		MaxWheelBytes: 80 << 20,
		Allow: []CatalogEntry{
			{Name: "python-docx", Reason: "Word 交付物"},
			{Name: "openpyxl", Reason: "Excel"},
			{Name: "python-pptx", Reason: "PPT"},
			{Name: "lxml", Reason: "OOXML"},
			{Name: "pillow", Reason: "图片"},
			{Name: "numpy", Reason: "数值"},
			{Name: "matplotlib", Reason: "图表"},
			{Name: "pypdf", Reason: "PDF 读取"},
			{Name: "reportlab", Reason: "PDF 生成"},
			{Name: "markdown", Reason: "Markdown"},
			{Name: "pdfplumber", Reason: "PDF 抽取"},
		},
		Deny: []string{"setuptools", "pip"},
	}
}

func (r *Root) LoadCatalog() (Catalog, error) {
	raw, err := os.ReadFile(r.CatalogPath())
	if err != nil {
		return Catalog{}, err
	}
	var c Catalog
	if err := json.Unmarshal(raw, &c); err != nil {
		return Catalog{}, err
	}
	if c.MaxWheelBytes <= 0 {
		c.MaxWheelBytes = 80 << 20
	}
	return c, nil
}

func (c Catalog) allowed(name string) bool {
	n := normName(name)
	for _, e := range c.Allow {
		if normName(e.Name) == n {
			return true
		}
	}
	return false
}

func (c Catalog) denied(name string) bool {
	n := normName(name)
	for _, d := range c.Deny {
		if normName(d) == n {
			return true
		}
	}
	return false
}