package state

import (
	"errors"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/distributor/internal/bundle"
)

func TestCompareOutcomes(t *testing.T) {
	source := validManifest(t)
	tests := []struct {
		name   string
		status DestinationStatus
		want   Outcome
	}{
		{
			name:   "destination absent",
			status: DestinationStatus{},
			want:   OutcomeDestinationAbsent,
		},
		{
			name:   "destination unmanaged",
			status: DestinationStatus{HasContents: true},
			want:   OutcomeDestinationUnmanaged,
		},
		{
			name:   "invalid destination state",
			status: DestinationStatus{StateErr: errors.New("invalid json")},
			want:   OutcomeInvalidState,
		},
		{
			name:   "pipeline mismatch",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) { s.PipelineID = "other" })},
			want:   OutcomeIdentityMismatch,
		},
		{
			name:   "destination mismatch",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) { s.DestinationID = "other" })},
			want:   OutcomeIdentityMismatch,
		},
		{
			name:   "same source manifest",
			status: DestinationStatus{State: withState(t, source, nil)},
			want:   OutcomeSameSource,
		},
		{
			name: "destination older",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) {
				s.Source.Manifest.Created = source.Created.Add(-time.Hour)
			})},
			want: OutcomeDestinationOlder,
		},
		{
			name: "destination newer",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) {
				s.Source.Manifest.Created = source.Created.Add(time.Hour)
			})},
			want: OutcomeDestinationNewer,
		},
		{
			name: "same created digest conflict",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) {
				s.Source.Manifest.Files[0].SHA256 = "sha256:3333333333333333333333333333333333333333333333333333333333333333"
				s.Source.Manifest.Digest = bundle.BundleDigest(s.Source.Manifest.Files)
			})},
			want: OutcomeSameCreatedConflict,
		},
		{
			name: "different source id",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) {
				s.Source.Manifest.ID = "other.source"
			})},
			want: OutcomeDifferentSourceConflict,
		},
		{
			name: "invalid state object",
			status: DestinationStatus{State: withState(t, source, func(s *DistributorState) {
				s.Outputs[0].Kind = "other"
			})},
			want: OutcomeInvalidState,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := Compare(source, "reports", "archive", tt.status)
			if got.Outcome != tt.want {
				t.Fatalf("Compare() outcome = %s reason=%q, want %s", got.Outcome, got.Reason, tt.want)
			}
			if got.Reason == "" {
				t.Fatal("Compare() reason is empty")
			}
		})
	}
}

func withState(t *testing.T, source bundle.Manifest, mutate func(*DistributorState)) *DistributorState {
	t.Helper()
	stateManifest := source
	stateManifest.Files = append([]bundle.ManifestFile(nil), source.Files...)
	state := DistributorState{
		SchemaVersion: SchemaVersion,
		PipelineID:    "reports",
		DestinationID: "archive",
		PublishedAt:   time.Date(2026, 5, 30, 11, 12, 0, 0, time.UTC),
		Source:        SourceState{Manifest: stateManifest},
		Outputs: []OutputFile{{
			Path:       "report.md",
			Kind:       OutputKindSource,
			SourcePath: "report.md",
			SHA256:     source.Files[0].SHA256,
			Size:       source.Files[0].Size,
		}},
	}
	if mutate != nil {
		mutate(&state)
	}
	return &state
}