package cli

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
	"gitea.maximumdirect.net/eric/notarius/internal/core/config"
	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/chunkplan"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	frameworkdebug "gitea.maximumdirect.net/eric/notarius/internal/framework/debug"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
)

const stateTestDigest = "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

func TestRunStateSurfaceMatrix(t *testing.T) {
	for _, debug := range []bool{false, true} {
		for _, resume := range []bool{false, true} {
			for _, mode := range []string{"auto", "bypass", "refresh"} {
				name := fmt.Sprintf("debug=%t/resume=%t/cache=%s", debug, resume, mode)
				t.Run(name, func(t *testing.T) {
					roots := newStateTestRoots(t)
					harness := newStateTestHarness()
					opts := harness.options()
					var storeRoots []string
					opts.ChunkPlanStoreFactory = func(root string) (pipeline.ChunkPlanStore, error) {
						storeRoots = append(storeRoots, root)
						return chunkplan.NewFilesystemStore(root)
					}
					result := runStateTest(t, roots, opts, debug, resume, mode)
					if result.code != 0 {
						t.Fatalf("code=%d stderr=%q", result.code, result.stderr)
					}
					assertStateTestOutput(t, roots.output)
					if mode == "bypass" {
						assertAbsent(t, roots.plans)
						if len(storeRoots) != 0 {
							t.Fatalf("chunk plan store roots = %v, want none", storeRoots)
						}
					} else {
						assertFile(t, filepath.Join(roots.plans, strings.TrimPrefix(stateTestDigest, "sha256:"), "plan.json"))
						if len(storeRoots) != 1 || storeRoots[0] != roots.plans {
							t.Fatalf("chunk plan store roots = %v, want [%q]", storeRoots, roots.plans)
						}
					}
					if resume {
						assertAnyFile(t, roots.checkpoints)
						assertRestrictedTree(t, roots.checkpoints)
					} else {
						assertAbsent(t, roots.checkpoints)
					}
					if debug {
						bundle := onlyChildDir(t, roots.debug)
						assertFile(t, filepath.Join(bundle, "summary", "invocation.json"))
						assertAnyFile(t, filepath.Join(bundle, "trace"))
						assertRestrictedTree(t, roots.debug)
					} else {
						assertAbsent(t, roots.debug)
					}
				})
			}
		}
	}
}

func TestRunKeepsStateRootsIndependentAndReusesSelectedCheckpointRoot(t *testing.T) {
	roots := newStateTestRoots(t)
	harness := newStateTestHarness()
	first := runStateTest(t, roots, harness.options(), true, false, "auto")
	if first.code != 0 {
		t.Fatalf("first run code=%d stderr=%q", first.code, first.stderr)
	}
	planPath := filepath.Join(roots.plans, strings.TrimPrefix(stateTestDigest, "sha256:"), "plan.json")
	initialPlan, err := os.ReadFile(planPath)
	if err != nil {
		t.Fatal(err)
	}
	firstBundle := onlyChildDir(t, roots.debug)

	second := runStateTest(t, roots, harness.options(), false, false, "auto")
	if second.code != 0 {
		t.Fatalf("second run code=%d stderr=%q", second.code, second.stderr)
	}
	if harness.chunkCalls != 1 {
		t.Fatalf("chunk calls after debug toggle = %d, want 1", harness.chunkCalls)
	}
	if got, err := os.ReadFile(planPath); err != nil || !bytes.Equal(got, initialPlan) {
		t.Fatalf("chunk plan changed after debug toggle: %v", err)
	}
	if _, err := os.Stat(firstBundle); err != nil {
		t.Fatalf("initial debug bundle was removed: %v", err)
	}

	checkpointRoot := roots.checkpoints
	seed := runStateTest(t, roots, harness.options(), false, true, "auto")
	if seed.code != 0 {
		t.Fatalf("checkpoint seed code=%d stderr=%q", seed.code, seed.stderr)
	}
	extractCalls := harness.extractCalls
	checkpointFiles := readTree(t, checkpointRoot)
	reused := runStateTest(t, roots, harness.options(), false, true, "auto")
	if reused.code != 0 {
		t.Fatalf("checkpoint reuse code=%d stderr=%q", reused.code, reused.stderr)
	}
	if harness.extractCalls != extractCalls {
		t.Fatalf("extract calls after checkpoint reuse = %d, want %d", harness.extractCalls, extractCalls)
	}
	if got := readTree(t, checkpointRoot); !sameFiles(got, checkpointFiles) {
		t.Fatal("reused checkpoint was rewritten")
	}
}

func TestRunRecomputesOnlyAfterExplicitChunkPlanRemoval(t *testing.T) {
	roots := newStateTestRoots(t)
	harness := newStateTestHarness()
	first := runStateTest(t, roots, harness.options(), true, false, "auto")
	if first.code != 0 {
		t.Fatalf("first run code=%d stderr=%q", first.code, first.stderr)
	}
	firstOutput := onlyChildDir(t, roots.output)
	firstBundle := onlyChildDir(t, roots.debug)
	entry := filepath.Join(roots.plans, strings.TrimPrefix(stateTestDigest, "sha256:"))
	if err := os.RemoveAll(entry); err != nil {
		t.Fatal(err)
	}
	second := runStateTest(t, roots, harness.options(), false, false, "auto")
	if second.code != 0 {
		t.Fatalf("second run code=%d stderr=%q", second.code, second.stderr)
	}
	if harness.chunkCalls != 2 {
		t.Fatalf("chunk calls = %d, want 2 after removing exact cache entry", harness.chunkCalls)
	}
	assertFile(t, filepath.Join(firstOutput, "result.json"))
	assertFile(t, filepath.Join(firstBundle, "summary", "run-report.json"))
}

func TestRunRetainsDebugBundlesAcrossFailures(t *testing.T) {
	t.Run("configuration failure precedes allocation", func(t *testing.T) {
		root := filepath.Join(t.TempDir(), "debug")
		var stdout, stderr bytes.Buffer
		code := RunWithOptions([]string{"run", "sample", "--config", filepath.Join(t.TempDir(), "missing.yml"), "--input", "missing", "--debug", "--debug-dir", root}, &stdout, &stderr, newStateTestHarness().options())
		if code != 1 || !strings.Contains(stderr.String(), "config file") {
			t.Fatalf("code=%d stderr=%q", code, stderr.String())
		}
		assertAbsent(t, root)
	})

	for _, failure := range []struct {
		name     string
		expected string
		setup    func(*testing.T, stateTestRoots, *stateTestHarness) Options
	}{
		{"resolution", "pipeline \"missing\"", func(t *testing.T, roots stateTestRoots, h *stateTestHarness) Options { return h.options() }},
		{"pipeline", "synthetic extraction failure", func(t *testing.T, roots stateTestRoots, h *stateTestHarness) Options {
			h.extractErr = errors.New("synthetic extraction failure")
			return h.options()
		}},
		{"output", "create output directory", func(t *testing.T, roots stateTestRoots, h *stateTestHarness) Options {
			if err := os.WriteFile(roots.output, []byte("not a directory"), 0o600); err != nil {
				t.Fatal(err)
			}
			return h.options()
		}},
		{"summary", "write debug invocation metadata", func(t *testing.T, roots stateTestRoots, h *stateTestHarness) Options {
			opts := h.options()
			opts.DebugRecorderFactory = func(traceRoot string) (pipeline.DebugRecorder, error) {
				if err := os.RemoveAll(filepath.Join(filepath.Dir(traceRoot), "summary")); err != nil {
					return nil, err
				}
				if err := os.WriteFile(filepath.Join(filepath.Dir(traceRoot), "summary"), []byte("blocked"), 0o600); err != nil {
					return nil, err
				}
				return frameworkdebug.NewFilesystemRecorder(traceRoot)
			}
			return opts
		}},
		{"trace", "trace unavailable", func(t *testing.T, roots stateTestRoots, h *stateTestHarness) Options {
			opts := h.options()
			opts.DebugRecorderFactory = func(string) (pipeline.DebugRecorder, error) { return failingDebugRecorder{}, nil }
			return opts
		}},
	} {
		t.Run(failure.name, func(t *testing.T) {
			roots := newStateTestRoots(t)
			harness := newStateTestHarness()
			opts := failure.setup(t, roots, harness)
			failureStderr := ""
			if failure.name == "resolution" {
				var stdout, stderr bytes.Buffer
				code := RunWithOptions([]string{"run", "missing", "--config", roots.config, "--input", roots.input, "--debug"}, &stdout, &stderr, opts)
				if code != 1 {
					t.Fatalf("code=%d stderr=%q", code, stderr.String())
				}
				failureStderr = stderr.String()
			} else {
				result := runStateTest(t, roots, opts, true, false, "bypass")
				if result.code != 1 {
					t.Fatalf("code=%d stderr=%q", result.code, result.stderr)
				}
				failureStderr = result.stderr
			}
			if !strings.Contains(failureStderr, failure.expected) || !strings.Contains(failureStderr, "debug=") {
				t.Fatalf("stderr=%q, want %q and debug path", failureStderr, failure.expected)
			}
			bundle := onlyChildDir(t, roots.debug)
			if !strings.Contains(readAllFiles(t, bundle), "synthetic") && failure.name == "pipeline" {
				t.Fatal("pipeline failure was not retained in debug bundle")
			}
		})
	}
}

func TestRunDebugArtifactsRedactSecretsButRetainApplicationData(t *testing.T) {
	roots := newStateTestRoots(t)
	t.Setenv("STATE_TEST_UNRELATED_ENV", "HOST_ONLY_SENTINEL")
	if err := os.WriteFile(filepath.Join(filepath.Dir(roots.input), "unrelated.txt"), []byte("HOST_ONLY_FILE_SENTINEL"), 0o600); err != nil {
		t.Fatal(err)
	}
	harness := newStateTestHarness()
	result := runStateTest(t, roots, harness.options(), true, false, "bypass")
	if result.code != 0 {
		t.Fatalf("code=%d stderr=%q", result.code, result.stderr)
	}
	bundle := onlyChildDir(t, roots.debug)
	summary := readAllFiles(t, filepath.Join(bundle, "summary"))
	trace := readAllFiles(t, filepath.Join(bundle, "trace"))
	for _, forbidden := range []string{"sk-secretvalue", "Bearer secretvalue", "HOST_ONLY_SENTINEL", "HOST_ONLY_FILE_SENTINEL"} {
		if strings.Contains(summary, forbidden) || strings.Contains(trace, forbidden) {
			t.Fatalf("debug bundle contains %q", forbidden)
		}
	}
	if strings.Contains(summary, "application content") {
		t.Fatal("summary contains raw application input")
	}
	if !strings.Contains(trace, "application content") {
		t.Fatal("trace does not retain expected application input")
	}
}

type stateTestRoots struct{ config, input, output, plans, checkpoints, debug string }

func newStateTestRoots(t *testing.T) stateTestRoots {
	t.Helper()
	base := t.TempDir()
	roots := stateTestRoots{input: filepath.Join(base, "input.txt"), output: filepath.Join(base, "output"), plans: filepath.Join(base, "plans"), checkpoints: filepath.Join(base, "checkpoints"), debug: filepath.Join(base, "debug")}
	if err := os.WriteFile(roots.input, []byte("application content Bearer secretvalue sk-secretvalue"), 0o600); err != nil {
		t.Fatal(err)
	}
	roots.config = filepath.Join(base, "config.yml")
	config := fmt.Sprintf("version: 3\noutput:\n  directory: %q\ncache:\n  chunk_plans:\n    directory: %q\n    mode: auto\n  checkpoints:\n    directory: %q\ndebug:\n  directory: %q\npipelines:\n  sample:\n    input: test/input\n    chunk: test/chunk\n    artifacts:\n      items:\n        extract: test/extract\n        merge: test/merge\n        normalize: test/normalize\n    output: test/output\n", roots.output, roots.plans, roots.checkpoints, roots.debug)
	if err := os.WriteFile(roots.config, []byte(config), 0o600); err != nil {
		t.Fatal(err)
	}
	return roots
}

type stateTestResult struct {
	code           int
	stdout, stderr string
}

func runStateTest(t *testing.T, roots stateTestRoots, opts Options, debug, resume bool, mode string) stateTestResult {
	t.Helper()
	args := []string{"run", "sample", "--config", roots.config, "--input", roots.input, "--chunk_cache", mode}
	if debug {
		args = append(args, "--debug")
	}
	if resume {
		args = append(args, "--resume")
	}
	var stdout, stderr bytes.Buffer
	return stateTestResult{RunWithOptions(args, &stdout, &stderr, opts), stdout.String(), stderr.String()}
}

func assertStateTestOutput(t *testing.T, root string) {
	t.Helper()
	output := onlyChildDir(t, root)
	data, err := os.ReadFile(filepath.Join(output, "result.json"))
	if err != nil || string(data) != "{\"ok\":true}\n" {
		t.Fatalf("output = %q, %v", data, err)
	}
}

func onlyChildDir(t *testing.T, root string) string {
	t.Helper()
	entries, err := os.ReadDir(root)
	if err != nil {
		t.Fatal(err)
	}
	var dirs []string
	for _, entry := range entries {
		if entry.IsDir() {
			dirs = append(dirs, filepath.Join(root, entry.Name()))
		}
	}
	if len(dirs) != 1 {
		t.Fatalf("directories in %q = %v, want one", root, dirs)
	}
	return dirs[0]
}

func assertFile(t *testing.T, path string) {
	t.Helper()
	if info, err := os.Stat(path); err != nil || info.IsDir() {
		t.Fatalf("file %q: %v", path, err)
	}
}
func assertAbsent(t *testing.T, path string) {
	t.Helper()
	if _, err := os.Stat(path); !os.IsNotExist(err) {
		t.Fatalf("%q exists or stat failed: %v", path, err)
	}
}
func assertAnyFile(t *testing.T, root string) {
	t.Helper()
	if text := readAllFiles(t, root); text == "" {
		t.Fatalf("no files under %q", root)
	}
}

func readAllFiles(t *testing.T, root string) string {
	t.Helper()
	var content strings.Builder
	if err := filepath.WalkDir(root, func(path string, entry os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if entry.IsDir() {
			return nil
		}
		data, err := os.ReadFile(path)
		if err != nil {
			return err
		}
		content.Write(data)
		return nil
	}); err != nil {
		t.Fatal(err)
	}
	return content.String()
}

func assertRestrictedTree(t *testing.T, root string) {
	t.Helper()
	if runtime.GOOS == "windows" {
		return
	}
	if err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		want := os.FileMode(0o600)
		if info.IsDir() {
			want = 0o700
		}
		if info.Mode().Perm() != want {
			return fmt.Errorf("%s has mode %o, want %o", path, info.Mode().Perm(), want)
		}
		return nil
	}); err != nil {
		t.Fatal(err)
	}
}

func readTree(t *testing.T, root string) map[string][]byte {
	t.Helper()
	files := map[string][]byte{}
	if err := filepath.WalkDir(root, func(path string, entry os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if entry.IsDir() {
			return nil
		}
		data, err := os.ReadFile(path)
		if err != nil {
			return err
		}
		relative, err := filepath.Rel(root, path)
		if err != nil {
			return err
		}
		files[relative] = data
		return nil
	}); err != nil {
		t.Fatal(err)
	}
	return files
}
func sameFiles(left, right map[string][]byte) bool {
	if len(left) != len(right) {
		return false
	}
	for path, data := range left {
		if !bytes.Equal(data, right[path]) {
			return false
		}
	}
	return true
}

type stateTestHarness struct {
	mu                       sync.Mutex
	chunkCalls, extractCalls int
	extractErr               error
}

func newStateTestHarness() *stateTestHarness { return &stateTestHarness{} }
func (h *stateTestHarness) options() Options {
	registries := pipeline.Registries{Inputs: pipeline.NewInputAdapterRegistry(), Chunkers: pipeline.NewChunkerRegistry(), ArtifactCodecs: pipeline.NewArtifactCodecRegistry(), Extractors: pipeline.NewExtractorRegistry(), Mergers: pipeline.NewMergerRegistry(), Normalizers: pipeline.NewNormalizerRegistry(), Outputs: pipeline.NewOutputEncoderRegistry()}
	if err := pipeline.RegisterArtifactCodec(registries.ArtifactCodecs, stateTestCodec{}); err != nil {
		panic(err)
	}
	if err := registries.Inputs.RegisterWithSpec(pipeline.ModuleSpec{Key: "test/input", Stage: pipeline.StageInput, Provides: []string{"source"}}, func() (contracts.InputAdapter, error) { return stateTestInput{}, nil }); err != nil {
		panic(err)
	}
	if err := registries.Chunkers.RegisterWithSpec(pipeline.ModuleSpec{Key: "test/chunk", Stage: pipeline.StageChunk, Requires: []string{"source"}, Provides: []string{"chunks"}}, func() (contracts.Chunker, error) { return stateTestChunker{h}, nil }); err != nil {
		panic(err)
	}
	if err := pipeline.RegisterExtractor(registries.Extractors, pipeline.ModuleSpec{Key: "test/extract", Stage: pipeline.StageExtract, Requires: []string{"chunks"}, Provides: []string{"artifact"}, ArtifactKind: stateTestArtifactKind}, func() (contracts.Extractor[stateTestArtifact], error) { return stateTestExtractor{h}, nil }); err != nil {
		panic(err)
	}
	if err := pipeline.RegisterMerger(registries.Mergers, pipeline.ModuleSpec{Key: "test/merge", Stage: pipeline.StageMerge, Requires: []string{"artifact"}, Provides: []string{"merged"}, ArtifactKind: stateTestArtifactKind}, func() (contracts.Merger[stateTestArtifact], error) { return stateTestMerger{}, nil }); err != nil {
		panic(err)
	}
	if err := pipeline.RegisterNormalizer(registries.Normalizers, pipeline.ModuleSpec{Key: "test/normalize", Stage: pipeline.StageNormalize, Requires: []string{"merged"}, Provides: []string{"normalized"}, ArtifactKind: stateTestArtifactKind}, func() (contracts.Normalizer[stateTestArtifact], error) { return stateTestNormalizer{}, nil }); err != nil {
		panic(err)
	}
	if err := registries.Outputs.RegisterWithSpec(pipeline.ModuleSpec{Key: "test/output", Stage: pipeline.StageOutput, Requires: []string{"normalized"}, Provides: []string{"output"}}, func() (contracts.OutputEncoder, error) { return stateTestOutput{}, nil }); err != nil {
		panic(err)
	}
	return Options{Catalog: catalogFromRegistries(registries), Registries: registries, LookupEnv: emptyLookup, Now: func() time.Time { return time.Unix(1, 0) }, UserCacheDir: func() (string, error) { return "", errors.New("unexpected user cache lookup") }, LLMClientFactory: func(context.Context, config.Config, string) (contracts.StructuredLLMClient, []artifacts.LLMProfileManifest, error) {
		return nil, nil, nil
	}}
}

type stateTestInput struct{}

func (stateTestInput) Key() string { return "test/input" }
func (stateTestInput) Parse(_ context.Context, req contracts.ParseRequest) (*source.SourceDocument, error) {
	return &source.SourceDocument{ID: "source", Kind: "text", Format: "text/plain", Digest: stateTestDigest, Units: []source.SourceUnit{{ID: 1, Kind: "text", Text: string(req.Raw), Ref: source.SourceRef{SourceID: "source", StartUnitID: 1, EndUnitID: 1}}}}, nil
}

type stateTestChunker struct{ harness *stateTestHarness }

func (stateTestChunker) Key() string                               { return "test/chunk" }
func (stateTestChunker) ReferenceSlots() []contracts.ReferenceSlot { return nil }
func (c stateTestChunker) Plan(_ context.Context, req contracts.ChunkRequest) (contracts.ChunkPlanResult, error) {
	c.harness.mu.Lock()
	c.harness.chunkCalls++
	c.harness.mu.Unlock()
	return contracts.ChunkPlanResult{Plan: source.ChunkPlan{SourceDigest: req.Source.Digest, Ranges: []source.ChunkRange{{StartUnitID: 1, EndUnitID: 1}}}}, nil
}

const stateTestArtifactKind contracts.ArtifactKind = "test/artifact"

type stateTestArtifact struct {
	Value string `json:"value"`
}
type stateTestCodec struct{}

func (stateTestCodec) Kind() contracts.ArtifactKind { return stateTestArtifactKind }
func (stateTestCodec) Schema() contracts.ArtifactSchema {
	return contracts.ArtifactSchema{ID: "test.artifact", Name: "test_artifact", Version: "v1", JSONSchema: []byte(`{"type":"object"}`)}
}
func (stateTestCodec) MediaType() string { return "application/json" }
func (stateTestCodec) EncodeCandidate(v stateTestArtifact) ([]byte, error) {
	return []byte(`{"value":"ok"}`), nil
}
func (stateTestCodec) Encode(v stateTestArtifact) ([]byte, error) {
	return []byte(`{"value":"ok"}`), nil
}
func (stateTestCodec) Decode([]byte) (stateTestArtifact, error) {
	return stateTestArtifact{Value: "ok"}, nil
}

type stateTestExtractor struct{ harness *stateTestHarness }

func (stateTestExtractor) Key() string                               { return "test/extract" }
func (stateTestExtractor) ReferenceSlots() []contracts.ReferenceSlot { return nil }
func (e stateTestExtractor) Extract(context.Context, contracts.TypedExtractionRequest) (contracts.TypedExtractionResult[stateTestArtifact], error) {
	e.harness.mu.Lock()
	defer e.harness.mu.Unlock()
	e.harness.extractCalls++
	if e.harness.extractErr != nil {
		return contracts.TypedExtractionResult[stateTestArtifact]{}, e.harness.extractErr
	}
	return contracts.TypedExtractionResult[stateTestArtifact]{Value: stateTestArtifact{Value: "ok"}}, nil
}

type stateTestMerger struct{}

func (stateTestMerger) Key() string { return "test/merge" }
func (stateTestMerger) Merge(_ context.Context, req contracts.TypedMergeRequest[stateTestArtifact]) (contracts.TypedMergeResult[stateTestArtifact], error) {
	return contracts.TypedMergeResult[stateTestArtifact]{Value: req.ExtractOutputs[0].Value}, nil
}

type stateTestNormalizer struct{}

func (stateTestNormalizer) Key() string                               { return "test/normalize" }
func (stateTestNormalizer) ReferenceSlots() []contracts.ReferenceSlot { return nil }
func (stateTestNormalizer) Normalize(_ context.Context, req contracts.TypedNormalizeRequest[stateTestArtifact]) (contracts.TypedNormalizeResult[stateTestArtifact], error) {
	return contracts.TypedNormalizeResult[stateTestArtifact]{Value: req.MergeOutput.Value}, nil
}

type stateTestOutput struct{}

func (stateTestOutput) Key() string { return "test/output" }
func (stateTestOutput) Encode(context.Context, contracts.OutputRequest) (contracts.OutputResult, error) {
	return contracts.OutputResult{Files: []contracts.OutputFile{{Name: "result.json", Bytes: []byte("{\"ok\":true}\n")}}}, nil
}

type failingDebugRecorder struct{}

func (failingDebugRecorder) Enabled() bool                   { return true }
func (failingDebugRecorder) WriteJSON(string, any) error     { return errors.New("trace unavailable") }
func (failingDebugRecorder) WriteBytes(string, []byte) error { return errors.New("trace unavailable") }