package app

import (
	"bytes"
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
	"gitea.maximumdirect.net/eric/narratio/internal/config"
	"gitea.maximumdirect.net/eric/narratio/internal/manifest"
)

func TestRestoreHoldsTransitionLockBeforePlanning(t *testing.T) {
	workspaceRoot := t.TempDir()
	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
	fake := &storage.FakeBackend{}
	cfg, _, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)

	origStoreFn := newObjectStoreFromConfigFn
	origDiscoverFn := discoverRemoteCurrentStateFn
	origPlanFn := buildRestorePlanFn
	t.Cleanup(func() {
		newObjectStoreFromConfigFn = origStoreFn
		discoverRemoteCurrentStateFn = origDiscoverFn
		buildRestorePlanFn = origPlanFn
	})

	current, err := discoverRemoteCurrentState(context.Background(), cfg, fake)
	if err != nil {
		t.Fatalf("discoverRemoteCurrentState() error = %v", err)
	}
	planning := make(chan struct{})
	releasePlanning := make(chan struct{})
	newObjectStoreFromConfigFn = func(context.Context, *config.Config) (storage.ObjectStore, error) { return fake, nil }
	discoverRemoteCurrentStateFn = func(context.Context, *config.Config, storage.ObjectStore) (*RemoteCurrentState, error) {
		return current, nil
	}
	buildRestorePlanFn = func(context.Context, *config.Config, *RemoteCurrentState, storage.ObjectStore, RestorePlanOptions) (*RestorePlan, error) {
		close(planning)
		<-releasePlanning
		return &RestorePlan{}, nil
	}

	restoreDone := make(chan error, 1)
	go func() {
		restoreDone <- Restore(context.Background(), []string{
			cfg.Session.SessionID,
			"--config", pipelinePath,
			"--campaign-file", campaignPath,
			"--session", sessionPath,
		}, &bytes.Buffer{})
	}()
	<-planning

	runnerCtx, cancelRunner := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancelRunner()
	if _, err := executeStages(runnerCtx, cfg, nil, RunOptions{}); err == nil || !strings.Contains(err.Error(), "acquire session lock") {
		t.Fatalf("runner while restore plans error = %v, want session-lock failure", err)
	}

	close(releasePlanning)
	if err := <-restoreDone; err != nil {
		t.Fatalf("Restore() error = %v", err)
	}
}

func TestExecuteStagesRefusesIncompleteRestore(t *testing.T) {
	cfg := testConfig(t)
	paths := artifacts.NewLocalStore(cfg.Pipeline.Workspace.Root).SessionPathsFor(cfg.Session.Campaign, cfg.Session.SessionID)
	if err := writeRestoreMarker(paths); err != nil {
		t.Fatalf("writeRestoreMarker() error = %v", err)
	}

	_, err := executeStages(context.Background(), cfg, nil, RunOptions{})
	if err == nil || !strings.Contains(err.Error(), "restore is incomplete") {
		t.Fatalf("executeStages() error = %v, want incomplete restore failure", err)
	}
}

func TestForcedRestoreRetryClearsIncompleteMarker(t *testing.T) {
	workspaceRoot := t.TempDir()
	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
	fake := &storage.FakeBackend{}
	cfg, sessionPrefix, _, _ := seedRestoreCommittedState(t, fake, pipelinePath, campaignPath, sessionPath)
	artifactKey := sessionPrefix + "artifacts/session_recap.md"
	transcriptKey := sessionPrefix + "transcripts/full.json"
	seedRestoreObject(fake, artifactKey, []byte("remote recap\n"))
	seedRestoreObject(fake, transcriptKey, []byte("remote transcript\n"))

	sessionRoot := artifacts.SessionWorkDirForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
	mustWriteTestFile(t, filepath.Join(sessionRoot, "artifacts", "session_recap.md"), "local recap\n")
	mustWriteTestFile(t, filepath.Join(sessionRoot, "transcripts", "full.json"), "local transcript\n")
	fake.DownloadHook = func(call storage.FakeDownloadCall) error {
		if call.Key == transcriptKey {
			return context.Canceled
		}
		return nil
	}
	restoreWithStoreAndRealPhases(t, fake)

	var stdout bytes.Buffer
	var stderr bytes.Buffer
	args := []string{"session", "restore", cfg.Session.SessionID, "--config", pipelinePath, "--campaign-file", campaignPath, "--session", sessionPath, "--force"}
	if code := Execute(args, &stdout, &stderr); code == 0 {
		t.Fatal("forced restore exit code = 0, want partial-install failure")
	}
	markerPath := artifacts.SessionRestoreMarkerPathForCampaign(workspaceRoot, cfg.Session.Campaign, cfg.Session.SessionID)
	if _, err := os.Stat(markerPath); err != nil {
		t.Fatalf("incomplete restore marker missing after partial forced restore: %v", err)
	}
	mustReadEquals(t, filepath.Join(sessionRoot, "artifacts", "session_recap.md"), "remote recap\n")

	fake.DownloadHook = nil
	stdout.Reset()
	stderr.Reset()
	if code := Execute(args, &stdout, &stderr); code != 0 {
		t.Fatalf("restore retry exit code = %d, want 0; stderr=%q", code, stderr.String())
	}
	if _, err := os.Stat(markerPath); !os.IsNotExist(err) {
		t.Fatalf("incomplete restore marker should be cleared after retry; stat err=%v", err)
	}
	mustReadEquals(t, filepath.Join(sessionRoot, "transcripts", "full.json"), "remote transcript\n")
}

func TestRebaseRestoredManifestPathsRejectsUnsafeReferencesAndRebasesPortablePaths(t *testing.T) {
	for _, test := range []struct {
		name      string
		workDir   string
		output    string
		wantPath  string
		wantError string
	}{
		{
			name:     "unix absolute path within producer root",
			workDir:  "/producer/work/sample-campaign/2026-05-03/runs/20260519T010203Z-a1b2c3d4",
			output:   "/producer/work/sample-campaign/2026-05-03/artifacts/recap.md",
			wantPath: "artifacts/recap.md",
		},
		{
			name:     "windows absolute path within producer root",
			workDir:  `C:\producer\work\sample-campaign\2026-05-03\runs\20260519T010203Z-a1b2c3d4`,
			output:   `C:\producer\work\sample-campaign\2026-05-03\artifacts\recap.md`,
			wantPath: "artifacts/recap.md",
		},
		{
			name:      "absolute path outside producer root",
			workDir:   "/producer/work/sample-campaign/2026-05-03/runs/20260519T010203Z-a1b2c3d4",
			output:    "/another-machine/recap.md",
			wantError: "outside the producer session root",
		},
		{
			name:      "relative traversal",
			workDir:   "/producer/work/sample-campaign/2026-05-03/runs/20260519T010203Z-a1b2c3d4",
			output:    "../recap.md",
			wantError: "unsafe relative path",
		},
	} {
		t.Run(test.name, func(t *testing.T) {
			cfg := testConfig(t)
			m := manifest.New(cfg.Session.SessionID, nowUTC())
			m.Campaign = cfg.Session.Campaign
			m.RunID = "20260519T010203Z-a1b2c3d4"
			m.LocalWorkDir = test.workDir
			m.Stages["analyze"] = &manifest.StageRecord{Outputs: []manifest.ArtifactRecord{{Kind: "recap", LocalPath: test.output}}}
			destination := artifacts.SessionWorkDirForCampaign(cfg.Pipeline.Workspace.Root, cfg.Session.Campaign, cfg.Session.SessionID)

			err := rebaseRestoredManifestPaths(cfg, m, destination)
			if test.wantError != "" {
				if err == nil || !strings.Contains(err.Error(), test.wantError) {
					t.Fatalf("rebaseRestoredManifestPaths() error = %v, want %q", err, test.wantError)
				}
				return
			}
			if err != nil {
				t.Fatalf("rebaseRestoredManifestPaths() error = %v", err)
			}
			if got, want := m.Stages["analyze"].Outputs[0].LocalPath, filepath.Join(destination, test.wantPath); got != want {
				t.Fatalf("rebased local path = %q, want %q", got, want)
			}
		})
	}
}