package promptdef

import (
	"context"
	"errors"
	"io/fs"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
)

func TestFilesystemRepository_GetPromptDefinition(t *testing.T) {
	tmpDir := t.TempDir()
	if err := copyTree("testdata", tmpDir); err != nil {
		t.Fatalf("failed to copy testdata: %v", err)
	}

	repo := NewFilesystemRepository(tmpDir)
	ctx := context.Background()

	t.Run("valid inline prompt", func(t *testing.T) {
		p, err := repo.GetPromptDefinition(ctx, "valid-inline", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if p.ID != "valid-inline" {
			t.Fatalf("unexpected id: %q", p.ID)
		}
		if p.Version != "1.0.0" {
			t.Fatalf("unexpected version: %q", p.Version)
		}
		if p.OutputFormat != domain.FormatMarkdown {
			t.Fatalf("unexpected output format: %q", p.OutputFormat)
		}
		if p.Validation.ValidationMode != domain.ValidationBasic {
			t.Fatalf("unexpected validation mode: %q", p.Validation.ValidationMode)
		}
		if len(p.Templates) != 2 {
			t.Fatalf("expected 2 messages, got %d", len(p.Templates))
		}
		if len(p.Inputs) != 1 {
			t.Fatalf("expected 1 input, got %d", len(p.Inputs))
		}
		if p.Inputs[0].ContentType != "text/markdown" {
			t.Fatalf("expected input content_type to be preserved, got %q", p.Inputs[0].ContentType)
		}
	})

	t.Run("valid file-backed prompt", func(t *testing.T) {
		p, err := repo.GetPromptDefinition(ctx, "valid-file-backed", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if len(p.Templates) != 2 {
			t.Fatalf("expected 2 messages, got %d", len(p.Templates))
		}
		if !strings.Contains(p.Templates[1].Content, "{{input \"transcript\"}}") {
			t.Fatalf("expected content_file template body to be loaded, got %q", p.Templates[1].Content)
		}
		if p.Templates[1].ContentFile == "" {
			t.Fatal("expected ContentFile source metadata to be preserved")
		}
		if !filepath.IsAbs(p.Templates[1].ContentFile) {
			t.Fatalf("expected resolved content_file path to be absolute, got %q", p.Templates[1].ContentFile)
		}
	})

	t.Run("valid cache control with ttl", func(t *testing.T) {
		p, err := repo.GetPromptDefinition(ctx, "valid-cache-control-ttl", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if len(p.Templates) != 2 {
			t.Fatalf("expected 2 messages, got %d", len(p.Templates))
		}
		assertCacheControl(t, p.Templates[0].CacheControl, domain.CacheControlEphemeral, "1h")
		if p.Templates[1].CacheControl != nil {
			t.Fatalf("expected second message cache control to be nil, got %#v", p.Templates[1].CacheControl)
		}
	})

	t.Run("valid cache control without ttl", func(t *testing.T) {
		p, err := repo.GetPromptDefinition(ctx, "valid-cache-control-without-ttl", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if len(p.Templates) != 2 {
			t.Fatalf("expected 2 messages, got %d", len(p.Templates))
		}
		assertCacheControl(t, p.Templates[0].CacheControl, domain.CacheControlEphemeral, "")
		if p.Templates[1].CacheControl != nil {
			t.Fatalf("expected second message cache control to be nil, got %#v", p.Templates[1].CacheControl)
		}
	})

	t.Run("valid nested file-backed prompt resolves content file relative to nested YAML", func(t *testing.T) {
		nestedDir := filepath.Join(tmpDir, "dnd", "recap")
		if err := os.MkdirAll(nestedDir, 0o755); err != nil {
			t.Fatal(err)
		}
		writePromptTestFile(t, filepath.Join(nestedDir, "nested_recap.yaml"), `
id: nested-recap
version: "1.0.0"
messages:
  - role: user
    content_file: ./nested_recap.user.tmpl
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)
		writePromptTestFile(t, filepath.Join(nestedDir, "nested_recap.user.tmpl"), `Nested recap: {{input "transcript"}}`)

		p, err := repo.GetPromptDefinition(ctx, "nested-recap", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if len(p.Templates) != 1 {
			t.Fatalf("expected one template, got %d", len(p.Templates))
		}
		if !strings.Contains(p.Templates[0].Content, "Nested recap") {
			t.Fatalf("expected nested content file body, got %q", p.Templates[0].Content)
		}
		if !strings.Contains(p.Templates[0].ContentFile, filepath.Join("dnd", "recap", "nested_recap.user.tmpl")) {
			t.Fatalf("expected nested content file path, got %q", p.Templates[0].ContentFile)
		}
	})

	t.Run("prompt with default_profile", func(t *testing.T) {
		p, err := repo.GetPromptDefinition(ctx, "with-default-profile", "")
		if err != nil {
			t.Fatalf("expected no error, got %v", err)
		}
		if p.DefaultProfile != "local-default" {
			t.Fatalf("unexpected default profile: %q", p.DefaultProfile)
		}
		if len(p.Inputs) != 1 {
			t.Fatalf("expected one input, got %d", len(p.Inputs))
		}
		if p.Inputs[0].ContentType != "" {
			t.Fatalf("expected missing content_type to remain empty, got %q", p.Inputs[0].ContentType)
		}
	})

	t.Run("duplicate prompt IDs fail as ambiguous", func(t *testing.T) {
		writePromptTestFile(t, filepath.Join(tmpDir, "duplicate_a.yaml"), `
id: duplicate-prompt
version: "1.0.0"
messages:
  - role: user
    content: First duplicate.
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)
		nestedDir := filepath.Join(tmpDir, "nested")
		if err := os.MkdirAll(nestedDir, 0o755); err != nil {
			t.Fatal(err)
		}
		writePromptTestFile(t, filepath.Join(nestedDir, "duplicate_b.yaml"), `
id: duplicate-prompt
version: "2.0.0"
messages:
  - role: user
    content: Second duplicate.
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)

		_, err := repo.GetPromptDefinition(ctx, "duplicate-prompt", "")
		if !errors.Is(err, ErrInvalidPromptDefinition) {
			t.Fatalf("expected duplicate prompt to return ErrInvalidPromptDefinition, got %v", err)
		}
		for _, want := range []string{"duplicate prompt definition id", "duplicate_a.yaml", filepath.Join("nested", "duplicate_b.yaml")} {
			if !strings.Contains(err.Error(), want) {
				t.Fatalf("expected error to contain %q, got %v", want, err)
			}
		}
	})

	t.Run("duplicate prompt ID and requested version fails as ambiguous", func(t *testing.T) {
		writePromptTestFile(t, filepath.Join(tmpDir, "version_duplicate_a.yaml"), `
id: duplicate-version-prompt
version: "1.0.0"
messages:
  - role: user
    content: First duplicate version.
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)
		nestedDir := filepath.Join(tmpDir, "versioned")
		if err := os.MkdirAll(nestedDir, 0o755); err != nil {
			t.Fatal(err)
		}
		writePromptTestFile(t, filepath.Join(nestedDir, "version_duplicate_b.yaml"), `
id: duplicate-version-prompt
version: "1.0.0"
messages:
  - role: user
    content: Second duplicate version.
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)

		_, err := repo.GetPromptDefinition(ctx, "duplicate-version-prompt", "1.0.0")
		if !errors.Is(err, ErrInvalidPromptDefinition) {
			t.Fatalf("expected duplicate prompt version to return ErrInvalidPromptDefinition, got %v", err)
		}
		for _, want := range []string{"duplicate prompt definition id", "version \"1.0.0\"", "version_duplicate_a.yaml", filepath.Join("versioned", "version_duplicate_b.yaml")} {
			if !strings.Contains(err.Error(), want) {
				t.Fatalf("expected error to contain %q, got %v", want, err)
			}
		}
	})

	t.Run("non-matching malformed nested prompt is ignored for not found lookup", func(t *testing.T) {
		nestedDir := filepath.Join(tmpDir, "broken")
		if err := os.MkdirAll(nestedDir, 0o755); err != nil {
			t.Fatal(err)
		}
		writePromptTestFile(t, filepath.Join(nestedDir, "unrelated.yaml"), "id: [")

		_, err := repo.GetPromptDefinition(ctx, "does-not-exist-even-with-broken-nested-file", "")
		if !errors.Is(err, ErrPromptDefinitionNotFound) {
			t.Fatalf("expected ErrPromptDefinitionNotFound, got %v", err)
		}
	})

	t.Run("strict decode failure in nested prompt matches by YAML ID", func(t *testing.T) {
		nestedDir := filepath.Join(tmpDir, "strict")
		if err := os.MkdirAll(nestedDir, 0o755); err != nil {
			t.Fatal(err)
		}
		writePromptTestFile(t, filepath.Join(nestedDir, "not_named_like_id.yaml"), `
id: nested-strict-error
version: "1.0.0"
unknown_field: true
messages:
  - role: user
    content: Invalid because of unknown field.
output:
  format: markdown
  validation_mode: basic
  repair_attempts: 0
`)

		_, err := repo.GetPromptDefinition(ctx, "nested-strict-error", "")
		if !errors.Is(err, ErrInvalidYAML) {
			t.Fatalf("expected ErrInvalidYAML, got %v", err)
		}
		if !strings.Contains(err.Error(), filepath.Join("strict", "not_named_like_id.yaml")) {
			t.Fatalf("expected nested path in error, got %v", err)
		}
	})

	t.Run("version lookup", func(t *testing.T) {
		_, err := repo.GetPromptDefinition(ctx, "valid-inline", "9.9.9")
		if !errors.Is(err, ErrPromptDefinitionNotFound) {
			t.Fatalf("expected ErrPromptDefinitionNotFound, got %v", err)
		}
	})

	cases := []struct {
		name       string
		id         string
		targetErr  error
		errSubstrs []string
	}{
		{name: "invalid YAML", id: "invalid_yaml", targetErr: ErrInvalidYAML},
		{name: "missing id", id: "missing_id", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"id is required"}},
		{name: "no messages", id: "no_messages", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"at least one message is required"}},
		{name: "both content and content_file", id: "both_content_and_content_file", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"exactly one"}},
		{name: "neither content nor content_file", id: "neither_content_nor_content_file", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"exactly one"}},
		{name: "missing content_file", id: "missing_content_file", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"failed to read content_file"}},
		{name: "duplicate input names", id: "duplicate_input_names", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"duplicate input name"}},
		{name: "invalid validation mode", id: "invalid_validation_mode", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"invalid validation mode"}},
		{name: "json_schema without schema_path", id: "json_schema_without_schema_path", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"schema_path"}},
		{name: "unknown input field", id: "unknown_input_field", targetErr: ErrInvalidYAML, errSubstrs: []string{"field unknown_input_setting not found"}},
		{name: "empty cache control type", id: "empty_cache_control_type", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"cache_control", "type is required"}},
		{name: "unsupported cache control type", id: "unsupported_cache_control_type", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"cache_control", "unsupported type"}},
		{name: "unsupported cache control ttl", id: "unsupported_cache_control_ttl", targetErr: ErrInvalidPromptDefinition, errSubstrs: []string{"cache_control", "unsupported ttl"}},
		{name: "unknown cache control field", id: "unknown_cache_control_field", targetErr: ErrInvalidYAML, errSubstrs: []string{"field unexpected not found"}},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			_, err := repo.GetPromptDefinition(ctx, tc.id, "")
			if !errors.Is(err, tc.targetErr) {
				t.Fatalf("expected %v, got %v", tc.targetErr, err)
			}
			for _, sub := range tc.errSubstrs {
				if !strings.Contains(err.Error(), sub) {
					t.Fatalf("expected error to contain %q, got %v", sub, err)
				}
			}
		})
	}

	t.Run("prompt definition not found", func(t *testing.T) {
		_, err := repo.GetPromptDefinition(ctx, "does-not-exist", "")
		if !errors.Is(err, ErrPromptDefinitionNotFound) {
			t.Fatalf("expected ErrPromptDefinitionNotFound, got %v", err)
		}
	})
}

func assertCacheControl(t *testing.T, got *domain.CacheControl, wantType domain.CacheControlType, wantTTL string) {
	t.Helper()
	if got == nil {
		t.Fatal("expected cache control, got nil")
	}
	if got.Type != wantType {
		t.Fatalf("unexpected cache control type: got %q want %q", got.Type, wantType)
	}
	if got.TTL != wantTTL {
		t.Fatalf("unexpected cache control ttl: got %q want %q", got.TTL, wantTTL)
	}
}

func writePromptTestFile(t *testing.T, path string, content string) {
	t.Helper()
	if err := os.WriteFile(path, []byte(strings.TrimLeft(content, "\n")), 0o644); err != nil {
		t.Fatalf("failed to write prompt test file %q: %v", path, err)
	}
}

func copyTree(src, dst string) error {
	return filepath.WalkDir(src, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		rel, err := filepath.Rel(src, path)
		if err != nil {
			return err
		}
		if rel == "." {
			return nil
		}

		target := filepath.Join(dst, rel)
		if d.IsDir() {
			return os.MkdirAll(target, 0o755)
		}

		data, err := os.ReadFile(path)
		if err != nil {
			return err
		}
		return os.WriteFile(target, data, 0o644)
	})
}