package bazel

import (
	"strings"
)

// This function only handles fully formed labels, not label expressions, such as
// '//...', '//pkg/edge/edgeadmin/...', etc. It does NOT perform any validation of
// the input labels because it assumes the input is derived from the output of
// Bazel directly. If you need to validate labels, do so before simplifying them.
//
// Will not simplify repository references for external repositories because
// the function does not know the workspace label (i.e., you can only simplify
// @edge_infra//pkg/edge to //pkg/edge if you know that you are currently in
// the @edge_infra workspace).
func SimplifyLabel(l string) string {
	// remove '//' before splitting on path
	tokens := strings.Split(strings.TrimPrefix(l, "//"), "/")
	// get last token in package path, which is the package name + the target.
	// e.g., pkg/edge/edgeadmin:cli -> cli:cli
	// then separate target name from it by splitting on ":"
	targetTokens := strings.Split(tokens[len(tokens)-1], ":")
	// length of 1 means we already got the simplified label as input, e.g.,
	// pkg/edge/foo
	if len(targetTokens) == 1 {
		return strings.Join(tokens, "/")
	}
	// simplify target labels referring to target with same name as package
	// e.g., pkg/edge:edge -> pkg/edge
	if targetTokens[0] == targetTokens[1] {
		tokens[len(tokens)-1] = targetTokens[0]
	}
	return strings.Join(tokens, "/")
}

// PackageFromLabel returns the package name for the given label, e.g.:
//
//	//cmd/f8n/foo:container_push -> //cmd/f8n/foo
//
// If an invalid label is passed in, an empty string is returned.
func PackageFromLabel(l string) string {
	return strings.Split(l, ":")[0]
}