package version

import (
	"runtime/debug"
	"testing"
)

func buildInfoWith(settings ...debug.BuildSetting) func() (*debug.BuildInfo, bool) {
	return func() (*debug.BuildInfo, bool) {
		return &debug.BuildInfo{Settings: settings}, true
	}
}

func TestResolve_precedenceAndFallback(t *testing.T) {
	t.Parallel()

	noBuildInfo := func() (*debug.BuildInfo, bool) { return nil, false }

	tests := []struct {
		name          string
		ldflagsCommit string
		readBuildInfo func() (*debug.BuildInfo, bool)
		want          string
	}{
		{
			name:          "ldflags stamp wins over build info",
			ldflagsCommit: "abc123def456-dirty",
			readBuildInfo: buildInfoWith(debug.BuildSetting{Key: "vcs.revision", Value: "ffffffffffffffffffffffffffffffffffffffff"}),
			want:          "abc123def456-dirty",
		},
		{
			name:          "no stamp, no build info",
			readBuildInfo: noBuildInfo,
			want:          "unknown",
		},
		{
			name:          "build info without vcs settings",
			readBuildInfo: buildInfoWith(),
			want:          "unknown",
		},
		{
			name: "full revision truncated to 12 chars",
			readBuildInfo: buildInfoWith(
				debug.BuildSetting{Key: "vcs.revision", Value: "0123456789abcdef0123456789abcdef01234567"},
				debug.BuildSetting{Key: "vcs.modified", Value: "false"},
			),
			want: "0123456789ab",
		},
		{
			name: "modified tree gets dirty suffix",
			readBuildInfo: buildInfoWith(
				debug.BuildSetting{Key: "vcs.revision", Value: "0123456789abcdef0123456789abcdef01234567"},
				debug.BuildSetting{Key: "vcs.modified", Value: "true"},
			),
			want: "0123456789ab-dirty",
		},
		{
			name: "short revision kept as-is",
			readBuildInfo: buildInfoWith(
				debug.BuildSetting{Key: "vcs.revision", Value: "abc123"},
			),
			want: "abc123",
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			if got := resolve(tc.ldflagsCommit, tc.readBuildInfo); got != tc.want {
				t.Errorf("resolve() = %q, want %q", got, tc.want)
			}
		})
	}
}