package validation

import (
	"path"
	"strings"
)

const defaultFileSizeLimit int64 = 1_000_000

func checkFileSize(tree *CandidateTree, settings *FileSizeSettings) error {
	limit := defaultFileSizeLimit
	if settings.LimitBytes != nil {
		limit = *settings.LimitBytes
	}
	exclusions := normalizedExclusions(settings.Exclusions)
	for _, entry := range tree.Entries() {
		if entry.Type != "blob" || !entry.HasSize || excludedByPath(entry.Path, exclusions) {
			continue
		}
		if entry.Size > limit {
			return &Failure{
				Check: FileSize,
				Findings: []Finding{{
					Path:    entry.Path,
					Message: "committed file exceeds the selected size limit",
				}},
				Measurement: &FileSizeMeasurement{Bytes: entry.Size, LimitBytes: limit},
			}
		}
	}
	return nil
}

func normalizedExclusions(exclusions []string) []string {
	result := make([]string, 0, len(exclusions))
	for _, exclusion := range exclusions {
		if exclusion == "" {
			continue
		}
		result = append(result, path.Clean(exclusion))
	}
	return result
}

func excludedByPath(filePath string, exclusions []string) bool {
	for _, exclusion := range exclusions {
		if exclusion == "." || filePath == exclusion || strings.HasPrefix(filePath, exclusion+"/") {
			return true
		}
	}
	return false
}