package rc

import (
	"embed"
	_ "embed"
	"path"
	"strings"

	"go.stargrave.org/godlighty"
)

const MIMEDir = "mime"

var (
	//go:embed mime
	mimes embed.FS

	CompressibleMIMEBundles = map[string]struct{}{
		"mail":     struct{}{},
		"playlist": struct{}{},
		"subtitle": struct{}{},
		"text":     struct{}{},
		"web":      struct{}{},
		"xml":      struct{}{},
	}
	CompressibleMIMEExts = []string{
		".dvi",
		".eps",
		".fb2",
		".meta4",
		".metalink",
		".ps",
	}
)

func parseMIME(p string) map[string]string {
	tsv, err := mimes.ReadFile(path.Join(MIMEDir, p))
	if err != nil {
		panic(err)
	}
	m := make(map[string]string)
	for _, line := range strings.Split(string(tsv), "\n") {
		if len(line) == 0 || line[0] == '#' {
			continue
		}
		cols := strings.SplitN(line, "\t", 2)
		m[cols[0]] = cols[1]
	}
	return m
}

func init() {
	entries, err := mimes.ReadDir(MIMEDir)
	if err != nil {
		panic(err)
	}
	for _, entry := range entries {
		bundle := entry.Name()
		_, allCompressible := CompressibleMIMEBundles[bundle]
		for ext, mediaType := range parseMIME(bundle) {
			godlighty.ContentTypes[ext] = mediaType
			if allCompressible {
				godlighty.CompressibleContentTypes[mediaType] = struct{}{}
			}
		}
	}
	CompressibleMIMEBundles = nil
	for _, ext := range CompressibleMIMEExts {
		mediaType := godlighty.ContentTypes[ext]
		godlighty.CompressibleContentTypes[mediaType] = struct{}{}
	}
	CompressibleMIMEExts = nil
}