package api_test

import (
	"encoding/json"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
	"time"

	"gopkg.in/yaml.v3"

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

func TestCaringAccessDescriptorExampleParses(t *testing.T) {
	var got api.CaringAccessDescriptor
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "access_descriptor.yaml"), &got)

	if got.Profile != api.CaringProfileCaring040RC2 {
		t.Fatalf("Profile = %q; want %q", got.Profile, api.CaringProfileCaring040RC2)
	}
	if got.CanonicalRole != api.CanonicalRoleDoer {
		t.Errorf("CanonicalRole = %q; want Doer", got.CanonicalRole)
	}
	if got.Scope.Level != api.ScopeLevelResource || got.Scope.Tenant != "tenant:alpha" {
		t.Errorf("Scope = %+v; want resource scope in tenant:alpha", got.Scope)
	}
	if len(got.Restrictions) != 1 || got.Restrictions[0] != api.RestrictionExportBlocked {
		t.Errorf("Restrictions = %v; want [ExportBlocked]", got.Restrictions)
	}
}

func TestCheckRequestExampleParses(t *testing.T) {
	var got api.CheckRequest
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "check_request.yaml"), &got)

	if got.Subject.ID != "user:alice" {
		t.Errorf("Subject.ID = %q; want user:alice", got.Subject.ID)
	}
	if got.Resource.ID != "document:internal-note" {
		t.Errorf("Resource.ID = %q; want document:internal-note", got.Resource.ID)
	}
	if got.CaringContext == nil {
		t.Fatal("CaringContext is nil")
	}
	if got.CaringContext.AccessPath != api.AccessPathDirect {
		t.Errorf("CaringContext.AccessPath = %q; want direct", got.CaringContext.AccessPath)
	}
}

func TestRegistryExamplesParse(t *testing.T) {
	var subjects api.SubjectManifest
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "subject_manifest.yaml"), &subjects)
	if len(subjects.Subjects) != 1 || subjects.Subjects[0].Type != api.SubjectTypeHuman {
		t.Fatalf("subjects did not parse as expected: %+v", subjects.Subjects)
	}

	var relationship api.RelationshipFact
	loadYAML(t, filepath.Join("..", "..", "examples", "caring", "relationship_fact.yaml"), &relationship)
	if relationship.Caring == nil {
		t.Fatal("RelationshipFact.Caring is nil")
	}
	if relationship.Caring.SubjectType != api.SubjectTypeGroup {
		t.Errorf("RelationshipFact.Caring.SubjectType = %q; want Group", relationship.Caring.SubjectType)
	}
}

func TestDecisionAndAuditExamplesParse(t *testing.T) {
	var decision api.DecisionEnvelope
	loadJSON(t, filepath.Join("..", "..", "examples", "caring", "decision_envelope.json"), &decision)
	if decision.Effect != api.DecisionEffectAllow {
		t.Errorf("Decision.Effect = %q; want allow", decision.Effect)
	}
	if decision.Lifetime == nil || decision.Lifetime.Kind != api.DecisionLifetimeTTL {
		t.Fatalf("Decision.Lifetime = %+v; want ttl", decision.Lifetime)
	}
	if decision.ContractVersion != api.DecisionRecordContractV1 {
		t.Errorf("Decision.ContractVersion = %q", decision.ContractVersion)
	}
	if decision.Caring == nil || decision.Caring.Profile != api.CaringProfileCaring040RC2 {
		t.Fatalf("Decision.Caring = %+v; want CARING profile metadata", decision.Caring)
	}
	if len(decision.Caring.ConformanceFindings) != 1 {
		t.Errorf("ConformanceFindings len = %d; want 1", len(decision.Caring.ConformanceFindings))
	}

	var audit api.AuditEvent
	loadJSON(t, filepath.Join("..", "..", "examples", "caring", "audit_event.json"), &audit)
	if audit.DecisionID != decision.ID {
		t.Errorf("Audit.DecisionID = %q; want %q", audit.DecisionID, decision.ID)
	}

	var exposure api.CaringExposureEvent
	loadJSON(t, filepath.Join("..", "..", "examples", "caring", "exposure_event.json"), &exposure)
	if exposure.Type != api.ExposureEventSupport {
		t.Errorf("Exposure.Type = %q; want X-Support", exposure.Type)
	}
	if len(exposure.ExposureModes) != 1 || exposure.ExposureModes[0] != api.ExposureModeMasked {
		t.Errorf("Exposure.ExposureModes = %v; want [Masked]", exposure.ExposureModes)
	}
}

func TestActionAuthorizationExampleParses(t *testing.T) {
	var authorization api.ActionAuthorization
	loadJSON(t, filepath.Join("..", "..", "examples", "caring", "action_authorization.json"), &authorization)
	if authorization.Status != api.ActionAuthorizationApproved {
		t.Fatalf("Status = %q; want approved", authorization.Status)
	}
	if authorization.Request.Action != "destroy" || authorization.Decision.Binding == nil {
		t.Fatalf("authorization is not action-bound: %+v", authorization)
	}
	if authorization.Approvals.RequiredCount != 2 || len(authorization.Approvals.Entries) != 2 {
		t.Fatalf("Approvals = %+v; want two-person approval", authorization.Approvals)
	}
	wantBinding := api.NewDecisionBinding(authorization.Request)
	if !reflect.DeepEqual(authorization.Decision.Binding, wantBinding) {
		t.Fatalf("Decision.Binding = %+v; want canonical binding %+v", authorization.Decision.Binding, wantBinding)
	}
}

func TestRequestDigestIgnoresIDAndChangesWithAction(t *testing.T) {
	request := api.CheckRequest{
		ID:      "check:one",
		Tenant:  "tenant:alpha",
		Subject: api.SubjectRef{ID: "user:alice", Type: api.SubjectTypeHuman},
		Action:  "read",
		Resource: api.ResourceRef{
			ID:     "document:internal-note",
			Type:   "document",
			System: "markitect-tool",
		},
		Context: map[string]any{"purpose": "project-delivery"},
	}
	first := api.RequestDigest(request)
	if !strings.HasPrefix(first, "sha256:") || len(first) != len("sha256:")+64 {
		t.Fatalf("RequestDigest = %q", first)
	}

	same := request
	same.ID = "check:other"
	same.PolicyVersion = "v9"
	if api.RequestDigest(same) != first {
		t.Fatal("digest changed when only id/policy_version changed")
	}

	changed := request
	changed.Action = "destroy"
	if api.RequestDigest(changed) == first {
		t.Fatal("digest did not change when action changed")
	}

	binding := api.NewDecisionBinding(request)
	if binding.RequestDigest != first {
		t.Fatalf("binding digest %q != RequestDigest %q", binding.RequestDigest, first)
	}
}

func TestApplyAllowLifetimeDefaultDeclaredAndNone(t *testing.T) {
	now := mustParseTime(t, "2026-08-29T12:00:00Z")

	allow := api.DecisionEnvelope{Effect: api.DecisionEffectAllow, Reason: "reader_relation"}
	api.ApplyAllowLifetime(&allow, "", now)
	if allow.Effect != api.DecisionEffectAllow || allow.Lifetime == nil {
		t.Fatalf("default TTL denied or skipped: %+v", allow)
	}
	if allow.Lifetime.TTL != "15m" || allow.Lifetime.ExpiresAt != "2026-08-29T12:15:00Z" {
		t.Fatalf("default lifetime = %+v", allow.Lifetime)
	}

	declared := api.DecisionEnvelope{Effect: api.DecisionEffectAllow, Reason: "reader_relation"}
	api.ApplyAllowLifetime(&declared, "5m", now)
	if declared.Lifetime == nil || declared.Lifetime.TTL != "5m" || declared.Lifetime.ExpiresAt != "2026-08-29T12:05:00Z" {
		t.Fatalf("declared lifetime = %+v", declared.Lifetime)
	}

	unstated := api.DecisionEnvelope{Effect: api.DecisionEffectAllow, Reason: "reader_relation"}
	api.ApplyAllowLifetime(&unstated, "none", now)
	if unstated.Effect != api.DecisionEffectDeny || unstated.Reason != api.ReasonAllowLifetimeUnstated {
		t.Fatalf("unstated allow = %+v; want deny", unstated)
	}
	if unstated.Lifetime != nil {
		t.Fatalf("unstated allow still has lifetime %+v", unstated.Lifetime)
	}
}

func mustParseTime(t *testing.T, value string) time.Time {
	t.Helper()
	parsed, err := time.Parse(time.RFC3339, value)
	if err != nil {
		t.Fatalf("parse time %q: %v", value, err)
	}
	return parsed
}

func TestSchemaFilesAreJSON(t *testing.T) {
	schemaDir := filepath.Join("..", "..", "schemas")
	entries, err := os.ReadDir(schemaDir)
	if err != nil {
		t.Fatalf("read schema dir: %v", err)
	}

	for _, entry := range entries {
		if entry.IsDir() || filepath.Ext(entry.Name()) != ".json" {
			continue
		}
		t.Run(entry.Name(), func(t *testing.T) {
			var got map[string]any
			loadJSON(t, filepath.Join(schemaDir, entry.Name()), &got)
			if got["$schema"] == "" || got["$id"] == "" {
				t.Fatalf("%s missing $schema or $id", entry.Name())
			}
		})
	}
}

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)
	}
}

func loadJSON(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 := json.Unmarshal(data, out); err != nil {
		t.Fatalf("unmarshal %s: %v", path, err)
	}
}