package promptdebug

import (
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptexec"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
)

func TestPromptDebugWriterWritesIsolatedArtifacts(t *testing.T) {
	root := filepath.Join(t.TempDir(), "operator-debug")
	writer, err := NewPromptDebugWriter(root)
	if err != nil {
		t.Fatalf("NewPromptDebugWriter() error = %v", err)
	}
	ref := promptDebugRef()
	preparationDir, err := writer.WritePreparation(ref, promptDebugPreparationFixture(), &promptexec.PreparationDebug{
		RenderedMessages: []promptexec.RenderedMessage{{Role: "system", Content: "Use the supplied weather facts."}},
		StructuredSchema: []byte(`{"type":"object","required":["summary"]}`),
		Endpoint:         "https://direct:resolved-secret-value@llm.example.test/v1/chat?api_key=resolved-secret-value",
		ParametersJSON:   []byte(`{"temperature":0.2,"api_key":"resolved-secret-value"}`),
	})
	if err != nil {
		t.Fatalf("WritePreparation() error = %v", err)
	}
	wantDirectory := filepath.Join(root, "daily", "2026-05-29", "run-123")
	if preparationDir != wantDirectory {
		t.Fatalf("WritePreparation() directory = %q, want %q", preparationDir, wantDirectory)
	}
	executionDir, err := writer.WriteExecution(ref, promptDebugExecutionFixture())
	if err != nil {
		t.Fatalf("WriteExecution() error = %v", err)
	}
	if executionDir != preparationDir {
		t.Fatalf("WriteExecution() directory = %q, want %q", executionDir, preparationDir)
	}
	preparationData := readPromptDebugFile(t, filepath.Join(preparationDir, "preparation.json"))
	for _, want := range []string{"Use the supplied weather facts.", `"type": "object"`, "https://llm.example.test/v1/chat?api_key=%5Bredacted%5D", `"temperature": 0.2`, `"api_key": "[redacted]"`} {
		if !strings.Contains(string(preparationData), want) {
			t.Fatalf("preparation debug artifact missing %q:\n%s", want, preparationData)
		}
	}
	executionData := readPromptDebugFile(t, filepath.Join(executionDir, "execution.json"))
	for _, want := range []string{"Generated forecast prose.", "validation details", `"status": "passed"`} {
		if !strings.Contains(string(executionData), want) {
			t.Fatalf("execution debug artifact missing %q:\n%s", want, executionData)
		}
	}
	for _, data := range [][]byte{preparationData, executionData} {
		if strings.Contains(string(data), "credential") || strings.Contains(string(data), "resolved-secret-value") {
			t.Fatalf("debug artifact contains credentials:\n%s", data)
		}
	}
	if runtime.GOOS != "windows" {
		assertPromptDebugMode(t, root, debugDirectoryMode)
		assertPromptDebugMode(t, preparationDir, debugDirectoryMode)
		assertPromptDebugMode(t, filepath.Join(preparationDir, "preparation.json"), debugFileMode)
		assertPromptDebugMode(t, filepath.Join(executionDir, "execution.json"), debugFileMode)
	}
}

func TestPromptDebugWriterAtomicallyReplacesArtifacts(t *testing.T) {
	writer, err := NewPromptDebugWriter(filepath.Join(t.TempDir(), "debug"))
	if err != nil {
		t.Fatalf("NewPromptDebugWriter() error = %v", err)
	}
	ref := promptDebugRef()
	first := promptDebugPreparationFixture()
	first.PromptHash = "old-hash"
	if _, err := writer.WritePreparation(ref, first, nil); err != nil {
		t.Fatalf("first WritePreparation() error = %v", err)
	}
	second := promptDebugPreparationFixture()
	second.PromptHash = "new-hash"
	directory, err := writer.WritePreparation(ref, second, nil)
	if err != nil {
		t.Fatalf("second WritePreparation() error = %v", err)
	}
	data := readPromptDebugFile(t, filepath.Join(directory, "preparation.json"))
	if strings.Contains(string(data), "old-hash") || !strings.Contains(string(data), "new-hash") {
		t.Fatalf("replacement artifact = %s", data)
	}
	temporary, err := filepath.Glob(filepath.Join(directory, ".preparation.json.*.tmp"))
	if err != nil || len(temporary) != 0 {
		t.Fatalf("temporary files = %v, %v", temporary, err)
	}
}

func TestPromptDebugWriterDisabledDoesNotAccessFilesystem(t *testing.T) {
	writer, err := NewPromptDebugWriter("")
	if err != nil {
		t.Fatalf("NewPromptDebugWriter() error = %v", err)
	}
	if writer.Enabled() {
		t.Fatal("disabled writer reports enabled")
	}
	directory, err := writer.WritePreparation(PromptDebugRef{ReportID: report.ID("../unsafe")}, promptDebugPreparationFixture(), nil)
	if err != nil || directory != "" {
		t.Fatalf("disabled WritePreparation() = %q, %v", directory, err)
	}
}

func TestPromptDebugWriterRejectsUnsafeRootsAndReferences(t *testing.T) {
	root := t.TempDir()
	if _, err := NewPromptDebugWriter("relative-debug"); err == nil {
		t.Fatal("NewPromptDebugWriter(relative) error = nil")
	}
	nonDirectory := filepath.Join(root, "not-a-directory")
	if err := os.WriteFile(nonDirectory, []byte("x"), 0o600); err != nil {
		t.Fatalf("write non-directory root: %v", err)
	}
	if _, err := NewPromptDebugWriter(nonDirectory); err == nil {
		t.Fatal("NewPromptDebugWriter(file) error = nil")
	}
	if runtime.GOOS != "windows" {
		target := filepath.Join(root, "target")
		link := filepath.Join(root, "root-link")
		if err := os.Mkdir(target, debugDirectoryMode); err != nil {
			t.Fatalf("create root symlink target: %v", err)
		}
		if err := os.Symlink(target, link); err != nil {
			t.Fatalf("create root symlink: %v", err)
		}
		if _, err := NewPromptDebugWriter(link); err == nil {
			t.Fatal("NewPromptDebugWriter(symlink) error = nil")
		}
	}

	writer, err := NewPromptDebugWriter(filepath.Join(root, "debug"))
	if err != nil {
		t.Fatalf("NewPromptDebugWriter() error = %v", err)
	}
	for _, ref := range []PromptDebugRef{
		{ReportID: report.ID("../daily"), ValidDate: "2026-05-29", RunID: "run-123"},
		{ReportID: report.Daily, ValidDate: "2026/05/29", RunID: "run-123"},
		{ReportID: report.Daily, ValidDate: "2026-05-29", RunID: "/run-123"},
		{ReportID: report.Daily, ValidDate: "not-a-date", RunID: "run-123"},
	} {
		if _, err := writer.WritePreparation(ref, promptDebugPreparationFixture(), nil); err == nil {
			t.Fatalf("WritePreparation(%#v) error = nil", ref)
		}
	}
	if runtime.GOOS != "windows" {
		outside := filepath.Join(root, "outside")
		if err := os.Mkdir(outside, debugDirectoryMode); err != nil {
			t.Fatalf("create symlink component target: %v", err)
		}
		if err := os.Symlink(outside, filepath.Join(root, "debug", "daily")); err != nil {
			t.Fatalf("create symlink component: %v", err)
		}
		if _, err := writer.WritePreparation(promptDebugRef(), promptDebugPreparationFixture(), nil); err == nil {
			t.Fatal("WritePreparation(symlink component) error = nil")
		}
	}
}

func promptDebugRef() PromptDebugRef {
	return PromptDebugRef{ReportID: report.Daily, ValidDate: "2026-05-29", RunID: "run-123"}
}

func promptDebugPreparationFixture() promptexec.Preparation {
	startedAt := time.Date(2026, 5, 29, 12, 0, 0, 0, time.UTC)
	return promptexec.Preparation{
		PromptID: "weather.daily", PromptVersion: "v1", PromptHash: "prompt-hash", RenderedPromptHash: "rendered-hash",
		InputHashes: map[string]string{"data_package": "input-hash"}, ProfileID: "local", BackendID: "local", ModelName: "weather-model",
		Output:    promptexec.OutputContract{Format: "json_schema", ValidationMode: "strict", SchemaPath: "schemas/daily.json"},
		StartedAt: startedAt, EndedAt: startedAt.Add(time.Second), Duration: time.Second, DataPackagePath: "/packages/daily.yaml",
	}
}

func promptDebugExecutionFixture() promptexec.Execution {
	startedAt := time.Date(2026, 5, 29, 12, 0, 0, 0, time.UTC)
	return promptexec.Execution{
		RunID: "run-123", PromptID: "weather.daily", PromptVersion: "v1", PromptHash: "prompt-hash", RenderedPromptHash: "rendered-hash",
		InputHashes: map[string]string{"data_package": "input-hash"}, ProfileID: "local", BackendID: "local", ModelName: "weather-model",
		GeneratedHash: "generated-hash", Usage: promptexec.TokenUsage{PromptTokens: 10, CompletionTokens: 5, TotalTokens: 15},
		StartedAt: startedAt, EndedAt: startedAt.Add(time.Second), Duration: time.Second,
		Validation:      promptexec.NewValidation(promptexec.ValidationPassed, "strict", "schemas/daily.json", []string{"validation details"}),
		DataPackagePath: "/packages/daily.yaml", RawOutput: []byte("Generated forecast prose."),
		Debug: &promptexec.ExecutionDebug{ValidationDiagnostics: []string{"validation details"}},
	}
}

func readPromptDebugFile(t *testing.T, path string) []byte {
	t.Helper()
	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read %q: %v", path, err)
	}
	return data
}

func assertPromptDebugMode(t *testing.T, path string, want os.FileMode) {
	t.Helper()
	info, err := os.Stat(path)
	if err != nil {
		t.Fatalf("stat %q: %v", path, err)
	}
	if got := info.Mode().Perm(); got != want {
		t.Fatalf("mode for %q = %#o, want %#o", path, got, want)
	}
}