package scanner

import (
	"regexp"
	"strings"
)

var (
	yearRe       = regexp.MustCompile(`[\.\s_-]((19|20)\d{2})[\.\s_-]`)
	resolutionRe = regexp.MustCompile(`(?i)\b(2160p|1080p|720p|480p|4K)\b`)
	sourceRe     = regexp.MustCompile(`(?i)\b(UHD\s*BluRay|BluRay|WEB-DL|WEBRip|HDTV|DVDRip)\b`)
	releaseRe    = regexp.MustCompile(`(?i)\b(REMUX|PROPER|REPACK)\b`)
	videoRe      = regexp.MustCompile(`(?i)\b(HEVC|H\.?264|H\.?265|x264|x265|AV1|XviD)\b`)
	audioRe      = regexp.MustCompile(`(?i)\b(TrueHD(\s*Atmos)?|DTS-HD|DTS|AAC|AC3|Atmos|EAC3)\b`)
	seriesRe1    = regexp.MustCompile(`(?i)(.+?)[\.\s_-]S(\d{1,2})E(\d{1,2})`)
	seriesRe2    = regexp.MustCompile(`(?i)(.+?)[\.\s_-](\d{1,2})x(\d{1,2})`)
)

func parseMovie(base string) map[string]interface{} {
	yearMatch := yearRe.FindStringSubmatchIndex(base)
	var titlePart string
	var year int
	if len(yearMatch) >= 4 {
		titlePart = base[:yearMatch[0]]
		year = atoi(base[yearMatch[2]:yearMatch[3]])
	} else {
		titlePart = base
	}
	title := cleanTitle(titlePart)
	if title == "" {
		return nil
	}
	result := map[string]interface{}{"title": title}
	if year > 0 {
		result["year"] = year
	}
	if m := resolutionRe.FindStringSubmatch(base); len(m) > 1 {
		result["resolution"] = m[1]
	}
	if m := sourceRe.FindStringSubmatch(base); len(m) > 1 {
		result["source"] = m[1]
	}
	if m := releaseRe.FindStringSubmatch(base); len(m) > 1 {
		result["releaseType"] = m[1]
	}
	if m := videoRe.FindStringSubmatch(base); len(m) > 1 {
		result["videoCodec"] = m[1]
	}
	if m := audioRe.FindStringSubmatch(base); len(m) > 0 {
		result["audio"] = m[0]
	}
	return result
}

func parseSeries(base string) map[string]interface{} {
	for _, re := range []*regexp.Regexp{seriesRe1, seriesRe2} {
		m := re.FindStringSubmatch(base)
		if len(m) >= 4 {
			title := cleanTitle(m[1])
			season := atoi(m[2])
			episode := atoi(m[3])
			if title == "" || season <= 0 || episode <= 0 {
				continue
			}
			result := map[string]interface{}{
				"title":   title,
				"season":  season,
				"episode": episode,
			}
			if rm := resolutionRe.FindStringSubmatch(base); len(rm) > 1 {
				result["resolution"] = rm[1]
			}
			if vm := videoRe.FindStringSubmatch(base); len(vm) > 1 {
				result["videoCodec"] = vm[1]
			}
			if am := audioRe.FindStringSubmatch(base); len(am) > 0 {
				result["audio"] = am[0]
			}
			return result
		}
	}
	return nil
}

func cleanTitle(s string) string {
	return strings.TrimSpace(strings.ReplaceAll(strings.ReplaceAll(s, ".", " "), "_", " "))
}

func atoi(s string) int {
	n := 0
	for _, c := range s {
		if c < '0' || c > '9' {
			return 0
		}
		n = n*10 + int(c-'0')
	}
	return n
}