package policy_test

import (
	"context"
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gopkg.in/yaml.v3"

	"github.com/netkingdom/flex-auth/internal/policy"
	"github.com/netkingdom/flex-auth/pkg/api"
)

func TestLoadPolicyPackageMarkdownValidates(t *testing.T) {
	pkg, err := policy.LoadAndValidateFile(context.Background(), filepath.Join("..", "..", "examples", "caring", "policy_package.md"))
	if err != nil {
		t.Fatalf("LoadAndValidateFile: %v", err)
	}

	if !pkg.Valid {
		t.Fatalf("pkg.Valid = false\n%s", formatValidation(pkg.Validation))
	}
	if pkg.Metadata.Caring.Profile != api.CaringProfileCaring040RC2 {
		t.Fatalf("metadata.Caring.Profile = %q; want %q", pkg.Metadata.Caring.Profile, api.CaringProfileCaring040RC2)
	}
	if pkg.Metadata.Namespace != "markitect:document" {
		t.Errorf("metadata.Namespace = %q; want markitect:document", pkg.Metadata.Namespace)
	}
	if !strings.HasPrefix(pkg.RegoModule, "package flexauth.markitect.documents") {
		t.Errorf("RegoModule prefix = %q; want flexauth.markitect.documents package", pkg.RegoModule[:min(len(pkg.RegoModule), 80)])
	}
	if len(pkg.RuleBlocks) != 1 || len(pkg.TestBlocks) != 1 || len(pkg.Fixtures) != 2 {
		t.Fatalf("blocks/fixtures = rules:%d tests:%d fixtures:%d; want 1/1/2", len(pkg.RuleBlocks), len(pkg.TestBlocks), len(pkg.Fixtures))
	}
	if len(pkg.Validation.Tests) != 2 {
		t.Fatalf("Validation.Tests len = %d; want 2", len(pkg.Validation.Tests))
	}
	for _, test := range pkg.Validation.Tests {
		if !test.Passed {
			t.Fatalf("test %s failed: %s", test.Name, test.Error)
		}
	}
	for _, fixture := range pkg.Validation.Fixtures {
		if !fixture.Passed {
			t.Fatalf("fixture %s failed: %s\nactual: %+v", fixture.ID, fixture.Error, fixture.Actual)
		}
	}
}

func TestRedactPolicyPackageMarkdownValidates(t *testing.T) {
	pkg, err := policy.LoadAndValidateFile(context.Background(), filepath.Join("..", "..", "examples", "caring", "redact_policy_package.md"))
	if err != nil {
		t.Fatalf("LoadAndValidateFile: %v", err)
	}

	if !pkg.Valid {
		t.Fatalf("pkg.Valid = false\n%s", formatValidation(pkg.Validation))
	}
	if len(pkg.Validation.Fixtures) != 1 {
		t.Fatalf("Validation.Fixtures len = %d; want 1", len(pkg.Validation.Fixtures))
	}
	fixture := pkg.Validation.Fixtures[0]
	if !fixture.Passed {
		t.Fatalf("fixture failed: %s\nactual: %+v", fixture.Error, fixture.Actual)
	}
	if fixture.Actual.Effect != api.DecisionEffectRedact {
		t.Fatalf("fixture.Actual.Effect = %q; want redact", fixture.Actual.Effect)
	}
	if len(fixture.Actual.Obligations) != 1 || fixture.Actual.Obligations[0].Type != "mask_fields" {
		t.Fatalf("fixture.Actual.Obligations = %+v; want mask_fields", fixture.Actual.Obligations)
	}
}

func TestCaringFindingsAreAdvisoryUntilEnforced(t *testing.T) {
	doc := inlinePolicy(false, "allow")
	pkg, err := policy.Load([]byte(doc), "inline-policy.md")
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	result := pkg.Validate(context.Background())
	if !result.Valid {
		t.Fatalf("result.Valid = false without CARING enforcement\n%s", formatValidation(result))
	}
	if len(result.CaringFindings) == 0 {
		t.Fatal("expected advisory CARING findings for missing metadata dimensions")
	}

	enforced := strings.Replace(doc, "enforce: false", "enforce: true", 1)
	pkg, err = policy.Load([]byte(enforced), "inline-policy.md")
	if err != nil {
		t.Fatalf("Load enforced: %v", err)
	}
	result = pkg.Validate(context.Background())
	if result.Valid {
		t.Fatalf("result.Valid = true with CARING enforcement; want invalid\n%s", formatValidation(result))
	}
}

func TestFixtureMismatchInvalidatesPackage(t *testing.T) {
	pkg, err := policy.Load([]byte(inlinePolicy(false, "deny")), "inline-policy.md")
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	result := pkg.Validate(context.Background())
	if result.Valid {
		t.Fatalf("result.Valid = true; want fixture mismatch to invalidate package\n%s", formatValidation(result))
	}
	if len(result.Fixtures) != 1 || result.Fixtures[0].Passed {
		t.Fatalf("fixture result = %+v; want one failed fixture", result.Fixtures)
	}
}

func TestPolicyPackageMetadataParses(t *testing.T) {
	var metadata api.PolicyPackageMetadata
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "policy_package.yaml"), &metadata)

	if metadata.Caring.Profile != api.CaringProfileCaring040RC2 {
		t.Fatalf("metadata.Caring.Profile = %q; want %q", metadata.Caring.Profile, api.CaringProfileCaring040RC2)
	}
	if len(metadata.Caring.Capabilities) != 1 || metadata.Caring.Capabilities[0] != api.CapabilityView {
		t.Errorf("metadata.Caring.Capabilities = %v; want [View]", metadata.Caring.Capabilities)
	}
	if len(metadata.Caring.Restrictions) != 1 || metadata.Caring.Restrictions[0] != api.RestrictionExportBlocked {
		t.Errorf("metadata.Caring.Restrictions = %v; want [ExportBlocked]", metadata.Caring.Restrictions)
	}
}

func TestPolicyFixtureParses(t *testing.T) {
	var fixture api.PolicyFixture
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "policy_fixture.yaml"), &fixture)

	if fixture.Expect.Effect != api.DecisionEffectAllow {
		t.Errorf("fixture.Expect.Effect = %q; want allow", fixture.Expect.Effect)
	}
	if fixture.Request.CaringContext == nil {
		t.Fatal("fixture.Request.CaringContext is nil")
	}
}

func inlinePolicy(enforce bool, expectedEffect string) string {
	enforceValue := "false"
	if enforce {
		enforceValue = "true"
	}

	fence := "```"
	doc := strings.ReplaceAll(`---
id: inline.allow
version: v1
package: flexauth.inline
caring:
  profile: caring-0.4.0-rc2
  enforce: ENFORCE
---

# Inline Policy

`+fence+`rego
default decision := {"effect": "allow", "reason": "ok"}
`+fence+`

`+fence+`rego test
package flexauth.inline_test

import future.keywords.if
import data.flexauth.inline

test_allow if {
  inline.decision.effect == "allow"
}
`+fence+`

`+fence+`yaml fixture
id: fixture:inline
request:
  subject:
    id: user:alice
  action: read
  resource:
    id: document:inline
expect:
  effect: EXPECTED
  reason: ok
`+fence+`
`, "ENFORCE", enforceValue)
	return strings.ReplaceAll(doc, "EXPECTED", expectedEffect)
}

func formatValidation(result policy.ValidationResult) string {
	data, err := json.MarshalIndent(result, "", "  ")
	if err != nil {
		return err.Error()
	}
	return string(data)
}

func loadYAML(t *testing.T, path string, out any) {
	t.Helper()

	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read %s: %v", path, err)
	}
	if err := yaml.Unmarshal(data, out); err != nil {
		t.Fatalf("unmarshal %s: %v", path, err)
	}
}