package publish

import (
	"context"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/distributor/internal/bundle"
	"gitea.maximumdirect.net/eric/distributor/internal/config"
	"gitea.maximumdirect.net/eric/distributor/internal/storage"
	"gitea.maximumdirect.net/eric/distributor/internal/storage/fake"
	"gitea.maximumdirect.net/eric/distributor/internal/testutil"
)

func TestBuildPlansSingleOwnerTakeoverByPolicy(t *testing.T) {
	tests := []struct {
		name        string
		takeover    config.TakeoverPolicy
		mutateState func(*bundle.Manifest, *testutil.DestinationStateOptions)
		wantAction  Action
		wantErr     string
	}{
		{
			name:     "default same pipeline different source",
			takeover: config.TakeoverPolicy{},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				manifest.ID = "other.source"
			},
			wantAction: ActionReplaceTakeover,
		},
		{
			name:     "same pipeline different newer source",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeSamePipeline},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				manifest.ID = "other.source"
				manifest.Created = manifest.Created.AddDate(0, 0, 1)
			},
			wantAction: ActionReplaceTakeover,
		},
		{
			name:     "default same pipeline different destination",
			takeover: config.TakeoverPolicy{},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				opts.DestinationID = "web"
			},
			wantAction: ActionReplaceTakeover,
		},
		{
			name:     "same pipeline refuses different pipeline",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeSamePipeline},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				opts.PipelineID = "other"
			},
			wantErr: "fail_conflict",
		},
		{
			name:     "same source allows different pipeline",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeSameSource},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				opts.PipelineID = "other"
			},
			wantAction: ActionReplaceTakeover,
		},
		{
			name:     "same source refuses different source",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeSameSource},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				manifest.ID = "other.source"
			},
			wantErr: "fail_conflict",
		},
		{
			name:     "any managed allows different pipeline",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeAnyManaged},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				manifest.ID = "other.source"
				opts.PipelineID = "other"
			},
			wantAction: ActionReplaceTakeover,
		},
		{
			name:     "never refuses different source",
			takeover: config.TakeoverPolicy{Mode: config.TakeoverModeNever},
			mutateState: func(manifest *bundle.Manifest, opts *testutil.DestinationStateOptions) {
				manifest.ID = "other.source"
			},
			wantErr: "fail_conflict",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			sourceBackend := fake.New()
			sourceBundle := testutil.WriteFakeSourceBundle(t, sourceBackend, "bundle", testutil.BundleOptions{})
			destinationBackend := fake.New()
			destinationManifest := sourceBundle.Manifest
			destinationManifest.Files = append([]bundle.ManifestFile(nil), sourceBundle.Manifest.Files...)
			opts := testutil.DestinationStateOptions{}
			tt.mutateState(&destinationManifest, &opts)
			testutil.WriteFakeDestinationState(t, destinationBackend, "bundle", destinationManifest, opts)

			req := takeoverRequest(sourceBackend, destinationBackend, sourceBundle, tt.takeover, config.ReconciliationModeReplace)
			plan, err := Build(context.Background(), req)
			if tt.wantErr != "" {
				if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
					t.Fatalf("Build() error = %v, want %q", err, tt.wantErr)
				}
				return
			}
			if err != nil {
				t.Fatalf("Build() error = %v", err)
			}
			if plan.Action != tt.wantAction {
				t.Fatalf("plan action = %s, want %s", plan.Action, tt.wantAction)
			}
		})
	}
}

func TestBuildDoesNotTakeOverInvalidOrUnmanagedDestination(t *testing.T) {
	tests := []struct {
		name    string
		prepare func(t *testing.T, backend *fake.Backend)
		wantErr string
	}{
		{
			name: "invalid state",
			prepare: func(t *testing.T, backend *fake.Backend) {
				t.Helper()
				statePath, err := storage.StatePath("bundle")
				if err != nil {
					t.Fatalf("state path: %v", err)
				}
				testutil.WriteFakeFile(t, backend, statePath, "{invalid")
			},
			wantErr: "fail_conflict",
		},
		{
			name: "unmanaged content",
			prepare: func(t *testing.T, backend *fake.Backend) {
				t.Helper()
				testutil.WriteFakeFile(t, backend, "bundle/old.txt", "old")
			},
			wantErr: "fail_unmanaged",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			sourceBackend := fake.New()
			sourceBundle := testutil.WriteFakeSourceBundle(t, sourceBackend, "bundle", testutil.BundleOptions{})
			destinationBackend := fake.New()
			tt.prepare(t, destinationBackend)

			req := takeoverRequest(sourceBackend, destinationBackend, sourceBundle, config.TakeoverPolicy{Mode: config.TakeoverModeAnyManaged}, config.ReconciliationModeReplace)
			_, err := Build(context.Background(), req)
			if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
				t.Fatalf("Build() error = %v, want %q", err, tt.wantErr)
			}
		})
	}
}

func TestExecuteTakeoverMergeDoesNotRetainOldSourceOutputs(t *testing.T) {
	sourceBackend := fake.New()
	sourceBundle := testutil.WriteFakeSourceBundle(t, sourceBackend, "bundle", testutil.BundleOptions{
		Files: []testutil.SourceFile{{Path: "report.md", Data: "# Report\nNew.\n"}},
	})
	destinationBackend := fake.New()
	oldManifest := sourceBundle.Manifest
	oldManifest.ID = "old.source"
	oldManifest.Files = []bundle.ManifestFile{
		{Path: "report.md", SHA256: bundle.FileDigest([]byte("old\n")), Size: int64(len("old\n"))},
		{Path: "summary.txt", SHA256: bundle.FileDigest([]byte("old summary\n")), Size: int64(len("old summary\n"))},
	}
	oldManifest.Digest = bundle.BundleDigest(oldManifest.Files)
	testutil.WriteFakeDestinationState(t, destinationBackend, "bundle", oldManifest, testutil.DestinationStateOptions{})

	req := takeoverRequest(sourceBackend, destinationBackend, sourceBundle, config.TakeoverPolicy{Mode: config.TakeoverModeSamePipeline}, config.ReconciliationModeMerge)
	plan, err := Build(context.Background(), req)
	if err != nil {
		t.Fatalf("Build() error = %v", err)
	}
	if plan.Action != ActionReplaceTakeover {
		t.Fatalf("plan action = %s, want %s", plan.Action, ActionReplaceTakeover)
	}
	if err := Execute(context.Background(), req, plan); err != nil {
		t.Fatalf("Execute() error = %v", err)
	}

	testutil.AssertFakeFile(t, destinationBackend, "bundle/report.md", "# Report\nNew.\n")
	testutil.AssertFakeMissing(t, destinationBackend, "bundle/summary.txt")
	destinationState := readFakeState(t, destinationBackend, "bundle")
	if got, want := len(destinationState.Outputs), 1; got != want {
		t.Fatalf("state output count = %d, want %d", got, want)
	}
	if got, want := destinationState.Source.Manifest.ID, sourceBundle.Manifest.ID; got != want {
		t.Fatalf("state source id = %q, want %q", got, want)
	}
}

func takeoverRequest(sourceBackend, destinationBackend *fake.Backend, sourceBundle bundle.Bundle, takeover config.TakeoverPolicy, reconciliationMode string) Request {
	return Request{
		PipelineID:            "reports",
		DestinationID:         "archive",
		SourceBundle:          sourceBundle,
		SourceBackend:         sourceBackend,
		DestinationBackend:    destinationBackend,
		DestinationBundlePath: sourceBundle.RootRelativePath,
		Publish:               config.PublishPolicy{Source: true},
		Reconciliation:        config.ReconciliationPolicy{Mode: reconciliationMode},
		Takeover:              takeover,
		Transfer:              defaultTransfer(),
		DistributorVersion:    "test",
	}
}