package source

import (
	"crypto/md5"
	"strings"
)

// Source is the base interface for all sources.
type Source interface {
	ID() int64
	Name() string
	Lang() string
}

// CatalogueSource is the full interface every source must implement.
type CatalogueSource interface {
	Source
	SupportsLatest() bool
	GetPopularManga(page int) (MangasPage, error)
	GetLatestUpdates(page int) (MangasPage, error)
	GetSearchManga(page int, query string, filters []Filter) (MangasPage, error)
	GetMangaDetails(manga SManga) (SManga, error)
	GetChapterList(manga SManga) ([]SChapter, error)
	GetPageList(chapter SChapter) ([]Page, error)
	// GetImageURL resolves the final image URL for a page.
	// Sources that embed image URLs directly in pages return page.ImageURL unchanged.
	GetImageURL(page Page) (string, error)
	GetFilterList() []Filter
}

// GenerateSourceID replicates Tachiyomi/Suwayomi HttpSource.generateId:
//
//	key = "${name.lowercase()}/$lang/$versionId"
//	MD5(key) → first 8 bytes as big-endian int64, sign bit cleared (& Long.MAX_VALUE)
func GenerateSourceID(name, lang string) int64 {
	return GenerateSourceIDv(name, lang, 1)
}

func GenerateSourceIDv(name, lang string, versionID int) int64 {
	key := strings.ToLower(name) + "/" + lang + "/" + itoa(versionID)
	b := md5.Sum([]byte(key))
	var id int64
	for i := 0; i < 8; i++ {
		id |= int64(b[i]) << (8 * (7 - i))
	}
	return id & int64(^uint64(0)>>1) // clear sign bit (& Long.MAX_VALUE)
}

func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	digits := []byte{}
	for n > 0 {
		digits = append([]byte{byte('0' + n%10)}, digits...)
		n /= 10
	}
	return string(digits)
}