package opapolicychecker

import (
	"bytes"
	"context"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/open-policy-agent/opa/v1/bundle"

	"github.com/beckn-one/beckn-onix/pkg/model"
)

// Helper: create a StepContext with the given action path and JSON body.
func makeStepCtx(action string, body string) *model.StepContext {
	req, _ := http.NewRequest("POST", "/bpp/caller/"+action, nil)
	return &model.StepContext{
		Context: context.Background(),
		Request: req,
		Body:    []byte(body),
	}
}

// Helper: write a .rego file to a temp dir and return the dir path.
func writePolicyDir(t *testing.T, filename, content string) string {
	t.Helper()
	dir := t.TempDir()
	err := os.WriteFile(filepath.Join(dir, filename), []byte(content), 0644)
	if err != nil {
		t.Fatalf("failed to write policy file: %v", err)
	}
	return dir
}

// --- Config Tests ---

func TestParseConfig_RequiresPolicySource(t *testing.T) {
	_, err := ParseConfig(map[string]string{})
	if err == nil {
		t.Fatal("expected error when no policy source given")
	}
}

func TestParseConfig_Defaults(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":     "dir",
		"location": "/tmp",
		"query":    "data.policy.violations",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(cfg.Actions) != 0 {
		t.Errorf("expected empty default actions (all enabled), got %v", cfg.Actions)
	}
	if !cfg.Enabled {
		t.Error("expected enabled=true by default")
	}
}

func TestParseConfig_RequiresQuery(t *testing.T) {
	_, err := ParseConfig(map[string]string{
		"type":     "dir",
		"location": "/tmp",
	})
	if err == nil {
		t.Fatal("expected error when no query given")
	}
}

func TestParseConfig_RuntimeConfigForwarding(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":                 "dir",
		"location":             "/tmp",
		"query":                "data.policy.violations",
		"minDeliveryLeadHours": "6",
		"customParam":          "value",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if cfg.RuntimeConfig["minDeliveryLeadHours"] != "6" {
		t.Errorf("expected minDeliveryLeadHours=6, got %q", cfg.RuntimeConfig["minDeliveryLeadHours"])
	}
	if cfg.RuntimeConfig["customParam"] != "value" {
		t.Errorf("expected customParam=value, got %q", cfg.RuntimeConfig["customParam"])
	}
}

func TestParseConfig_CustomActions(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":     "dir",
		"location": "/tmp",
		"query":    "data.policy.violations",
		"actions":  "confirm, select, init",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(cfg.Actions) != 3 {
		t.Fatalf("expected 3 actions, got %d: %v", len(cfg.Actions), cfg.Actions)
	}
	expected := []string{"confirm", "select", "init"}
	for i, want := range expected {
		if cfg.Actions[i] != want {
			t.Errorf("action[%d] = %q, want %q", i, cfg.Actions[i], want)
		}
	}
}

func TestParseConfig_PolicyPaths(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":     "url",
		"location": "https://example.com/a.rego, https://example.com/b.rego",
		"query":    "data.policy.violations",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(cfg.PolicyPaths) != 2 {
		t.Fatalf("expected 2 paths, got %d: %v", len(cfg.PolicyPaths), cfg.PolicyPaths)
	}
	if cfg.PolicyPaths[0] != "https://example.com/a.rego" {
		t.Errorf("path[0] = %q", cfg.PolicyPaths[0])
	}
}

// --- Evaluator Tests (with inline policies) ---

func TestEvaluator_NoViolations(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains msg if {
    input.value < 0
    msg := "value is negative"
}
`
	dir := writePolicyDir(t, "test.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{"value": 10}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations, got %d: %v", len(violations), violations)
	}
}

func TestEvaluator_WithViolation(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains msg if {
    input.value < 0
    msg := "value is negative"
}
`
	dir := writePolicyDir(t, "test.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{"value": -5}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Fatalf("expected 1 violation, got %d: %v", len(violations), violations)
	}
	if violations[0] != "value is negative" {
		t.Errorf("unexpected violation: %q", violations[0])
	}
}

func TestEvaluator_RuntimeConfig(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains msg if {
    input.value > to_number(data.config.maxValue)
    msg := "value exceeds maximum"
}
`
	dir := writePolicyDir(t, "test.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", map[string]string{"maxValue": "100"}, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// Under limit
	violations, err := eval.Evaluate(context.Background(), []byte(`{"value": 50}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations for value=50, got %v", violations)
	}

	// Over limit
	violations, err = eval.Evaluate(context.Background(), []byte(`{"value": 150}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Errorf("expected 1 violation for value=150, got %v", violations)
	}
}

func TestEvaluator_SkipsTestFiles(t *testing.T) {
	dir := t.TempDir()

	policy := `
package policy
import rego.v1
violations contains "always" if { true }
`
	os.WriteFile(filepath.Join(dir, "policy.rego"), []byte(policy), 0644)

	// Test file would cause compilation issues if loaded (different package)
	testFile := `
package policy_test
import rego.v1
import data.policy
test_something if { count(policy.violations) > 0 }
`
	os.WriteFile(filepath.Join(dir, "policy_test.rego"), []byte(testFile), 0644)

	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator should skip _test.rego files, but failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Errorf("expected 1 violation, got %d", len(violations))
	}
}

func TestEvaluator_InvalidJSON(t *testing.T) {
	policy := `
package policy
import rego.v1
violations := set()
`
	dir := writePolicyDir(t, "test.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	_, err = eval.Evaluate(context.Background(), []byte(`not json`))
	if err == nil {
		t.Error("expected error for invalid JSON")
	}
}

// --- Evaluator URL Fetch Tests ---

func TestEvaluator_FetchFromURL(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains msg if {
    input.value < 0
    msg := "value is negative"
}
`
	// Serve the policy via a local HTTP server
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/plain")
		w.Write([]byte(policy))
	}))
	defer srv.Close()

	eval, err := NewEvaluator([]string{srv.URL + "/test_policy.rego"}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator with URL failed: %v", err)
	}

	// Compliant
	violations, err := eval.Evaluate(context.Background(), []byte(`{"value": 10}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations, got %v", violations)
	}

	// Non-compliant
	violations, err = eval.Evaluate(context.Background(), []byte(`{"value": -1}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Errorf("expected 1 violation, got %v", violations)
	}
}

func TestEvaluator_FetchURL_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.NotFoundHandler())
	defer srv.Close()

	_, err := NewEvaluator([]string{srv.URL + "/missing.rego"}, "data.policy.violations", nil, false)
	if err == nil {
		t.Fatal("expected error for 404 URL")
	}
}

func TestEvaluator_FetchURL_InvalidScheme(t *testing.T) {
	_, err := NewEvaluator([]string{"ftp://example.com/policy.rego"}, "data.policy.violations", nil, false)
	if err == nil {
		t.Fatal("expected error for ftp:// scheme")
	}
}

func TestEvaluator_MixedLocalAndURL(t *testing.T) {
	// Local policy
	localPolicy := `
package policy
import rego.v1
violations contains "local_violation" if { input.local_bad }
`
	dir := writePolicyDir(t, "local.rego", localPolicy)

	// Remote policy (different rule, same package)
	remotePolicy := `
package policy
import rego.v1
violations contains "remote_violation" if { input.remote_bad }
`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(remotePolicy))
	}))
	defer srv.Close()

	eval, err := NewEvaluator([]string{dir, srv.URL + "/remote.rego"}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// Trigger both violations
	violations, err := eval.Evaluate(context.Background(), []byte(`{"local_bad": true, "remote_bad": true}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 2 {
		t.Errorf("expected 2 violations (local+remote), got %d: %v", len(violations), violations)
	}
}

// --- Evaluator with local file path in policySources ---

func TestEvaluator_LocalFilePath(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "from_file" if { input.bad }
`
	dir := t.TempDir()
	policyPath := filepath.Join(dir, "local_policy.rego")
	os.WriteFile(policyPath, []byte(policy), 0644)

	eval, err := NewEvaluator([]string{policyPath}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator with local path failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{"bad": true}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 || violations[0] != "from_file" {
		t.Errorf("expected [from_file], got %v", violations)
	}
}

// --- Rego Modularity Tests ---
// These tests prove that rego files can reference each other, supporting
// modular policy design to avoid rule bloat.

// TestEvaluator_CrossFileModularity verifies that multiple .rego files
// in the SAME package automatically share rules and data.
func TestEvaluator_CrossFileModularity(t *testing.T) {
	dir := t.TempDir()

	// File 1: defines a helper rule
	helpers := `
package policy
import rego.v1
is_high_value if { input.message.order.value > 10000 }
`
	os.WriteFile(filepath.Join(dir, "helpers.rego"), []byte(helpers), 0644)

	// File 2: uses the helper from file 1 (same package, auto-merged)
	rules := `
package policy
import rego.v1
violations contains "order too large" if { is_high_value }
`
	os.WriteFile(filepath.Join(dir, "rules.rego"), []byte(rules), 0644)

	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// High value order — should trigger
	violations, err := eval.Evaluate(context.Background(), []byte(`{"message":{"order":{"value":15000}}}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 || violations[0] != "order too large" {
		t.Errorf("expected [order too large], got %v", violations)
	}

	// Low value order — should not trigger
	violations, err = eval.Evaluate(context.Background(), []byte(`{"message":{"order":{"value":500}}}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations, got %v", violations)
	}
}

// TestEvaluator_CrossPackageImport verifies that rego files in DIFFERENT
// packages can import each other using `import data.<package>`.
func TestEvaluator_CrossPackageImport(t *testing.T) {
	dir := t.TempDir()

	// File 1: utility package with reusable helpers
	utils := `
package utils
import rego.v1
is_confirm if { input.context.action == "confirm" }
is_high_value if { input.message.order.value > 10000 }
`
	os.WriteFile(filepath.Join(dir, "utils.rego"), []byte(utils), 0644)

	// File 2: policy package imports from utils package
	rules := `
package policy
import rego.v1
import data.utils
violations contains "high value confirm blocked" if {
    utils.is_confirm
    utils.is_high_value
}
`
	os.WriteFile(filepath.Join(dir, "rules.rego"), []byte(rules), 0644)

	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// confirm + high value — should fire
	violations, err := eval.Evaluate(context.Background(), []byte(`{
		"context": {"action": "confirm"},
		"message": {"order": {"value": 50000}}
	}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Errorf("expected 1 violation, got %v", violations)
	}

	// search action — should NOT fire (action filter in rego)
	violations, err = eval.Evaluate(context.Background(), []byte(`{
		"context": {"action": "search"},
		"message": {"order": {"value": 50000}}
	}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations for search action, got %v", violations)
	}
}

// TestEvaluator_MultiFileOrganization demonstrates a realistic modular layout
// where policies are organized by concern (compliance, safety, rate-limiting)
// across separate files that all work together.
func TestEvaluator_MultiFileOrganization(t *testing.T) {
	dir := t.TempDir()

	// Shared helpers
	helpers := `
package helpers
import rego.v1
action_is(a) if { input.context.action == a }
value_exceeds(limit) if { input.message.order.value > limit }
`
	os.WriteFile(filepath.Join(dir, "helpers.rego"), []byte(helpers), 0644)

	// compliance.rego — compliance rules
	compliance := `
package policy
import rego.v1
import data.helpers
violations contains "compliance: missing provider" if {
    helpers.action_is("confirm")
    not input.message.order.provider
}
`
	os.WriteFile(filepath.Join(dir, "compliance.rego"), []byte(compliance), 0644)

	// safety.rego — safety rules
	safety := `
package policy
import rego.v1
import data.helpers
violations contains "safety: order value too high" if {
    helpers.action_is("confirm")
    helpers.value_exceeds(100000)
}
`
	os.WriteFile(filepath.Join(dir, "safety.rego"), []byte(safety), 0644)

	eval, err := NewEvaluator([]string{dir}, "data.policy.violations", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// Input that triggers BOTH violations
	violations, err := eval.Evaluate(context.Background(), []byte(`{
		"context": {"action": "confirm"},
		"message": {"order": {"value": 999999}}
	}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 2 {
		t.Errorf("expected 2 violations (compliance+safety), got %d: %v", len(violations), violations)
	}
}

// --- Enforcer Integration Tests ---

func TestEnforcer_Compliant(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "blocked" if { input.context.action == "confirm"; input.block }
`
	dir := writePolicyDir(t, "test.rego", policy)

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "dir",
		"location": dir,
		"query":    "data.policy.violations",
		"actions":  "confirm",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	ctx := makeStepCtx("confirm", `{"context": {"action": "confirm"}, "block": false}`)
	err = enforcer.CheckPolicy(ctx)
	if err != nil {
		t.Errorf("expected nil error for compliant message, got: %v", err)
	}
}

func TestEnforcer_NonCompliant(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "blocked" if { input.context.action == "confirm" }
`
	dir := writePolicyDir(t, "test.rego", policy)

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "dir",
		"location": dir,
		"query":    "data.policy.violations",
		"actions":  "confirm",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	ctx := makeStepCtx("confirm", `{"context": {"action": "confirm"}}`)
	err = enforcer.CheckPolicy(ctx)
	if err == nil {
		t.Fatal("expected error for non-compliant message, got nil")
	}

	// Should be a BadReqErr
	if _, ok := err.(*model.BadReqErr); !ok {
		t.Errorf("expected *model.BadReqErr, got %T: %v", err, err)
	}
}

func TestEnforcer_SkipsNonMatchingAction(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "blocked" if { true }
`
	dir := writePolicyDir(t, "test.rego", policy)

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "dir",
		"location": dir,
		"query":    "data.policy.violations",
		"actions":  "confirm",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	// Non-compliant body, but action is "search" — not in configured actions
	ctx := makeStepCtx("search", `{"context": {"action": "search"}}`)
	err = enforcer.CheckPolicy(ctx)
	if err != nil {
		t.Errorf("expected nil for non-matching action, got: %v", err)
	}
}

func TestEnforcer_DisabledPlugin(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "blocked" if { true }
`
	dir := writePolicyDir(t, "test.rego", policy)

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "dir",
		"location": dir,
		"query":    "data.policy.violations",
		"enabled":  "false",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	ctx := makeStepCtx("confirm", `{"context": {"action": "confirm"}}`)
	err = enforcer.CheckPolicy(ctx)
	if err != nil {
		t.Errorf("expected nil for disabled plugin, got: %v", err)
	}
}

// --- Enforcer with URL-sourced policy ---

func TestEnforcer_PolicyFromURL(t *testing.T) {
	policy := `
package policy
import rego.v1
violations contains "blocked" if { input.context.action == "confirm" }
`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(policy))
	}))
	defer srv.Close()

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "url",
		"location": srv.URL + "/block_confirm.rego",
		"query":    "data.policy.violations",
		"actions":  "confirm",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	ctx := makeStepCtx("confirm", `{"context": {"action": "confirm"}}`)
	err = enforcer.CheckPolicy(ctx)
	if err == nil {
		t.Fatal("expected error from URL-sourced policy, got nil")
	}
	if _, ok := err.(*model.BadReqErr); !ok {
		t.Errorf("expected *model.BadReqErr, got %T", err)
	}
}

// --- extractAction Tests ---

func TestExtractAction_FromURL(t *testing.T) {
	action := extractAction("/bpp/caller/confirm", nil)
	if action != "confirm" {
		t.Errorf("expected 'confirm', got %q", action)
	}
}

func TestExtractAction_FromBody(t *testing.T) {
	body := []byte(`{"context": {"action": "select"}}`)
	action := extractAction("/x", body)
	if action != "select" {
		t.Errorf("expected 'select', got %q", action)
	}
}

// --- Config Tests: Bundle Type ---

func TestParseConfig_BundleType(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":     "bundle",
		"location": "https://example.com/bundle.tar.gz",
		"query":    "data.retail.validation.result",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !cfg.IsBundle {
		t.Error("expected IsBundle=true for type=bundle")
	}
	if len(cfg.PolicyPaths) != 1 || cfg.PolicyPaths[0] != "https://example.com/bundle.tar.gz" {
		t.Errorf("expected 1 policy path, got %v", cfg.PolicyPaths)
	}
	if cfg.Query != "data.retail.validation.result" {
		t.Errorf("expected query 'data.retail.validation.result', got %q", cfg.Query)
	}
}

// --- Structured Result Format Tests ---

func TestEvaluator_StructuredResult_Valid(t *testing.T) {
	// Policy returns {"valid": true, "violations": []} — no violations expected
	policy := `
package retail.policy

import rego.v1

default result := {
  "valid": true,
  "violations": []
}
`
	dir := writePolicyDir(t, "policy.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.retail.policy.result", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{"message": {"order": {"items": []}}}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations for valid result, got %v", violations)
	}
}

func TestEvaluator_StructuredResult_WithViolations(t *testing.T) {
	// Policy returns {"valid": false, "violations": ["msg1", "msg2"]} when items have count <= 0
	policy := `
package retail.policy

import rego.v1

default result := {
  "valid": true,
  "violations": []
}

result := {
  "valid": count(violations) == 0,
  "violations": violations
}

violations contains msg if {
  some item in input.message.order.items
  item.quantity.count <= 0
  msg := sprintf("item %s: quantity must be > 0", [item.id])
}
`
	dir := writePolicyDir(t, "policy.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.retail.policy.result", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	// Non-compliant input
	body := `{
		"message": {
			"order": {
				"items": [
					{"id": "item1", "quantity": {"count": 0}},
					{"id": "item2", "quantity": {"count": 5}}
				]
			}
		}
	}`
	violations, err := eval.Evaluate(context.Background(), []byte(body))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Fatalf("expected 1 violation, got %d: %v", len(violations), violations)
	}
	if violations[0] != "item item1: quantity must be > 0" {
		t.Errorf("unexpected violation: %q", violations[0])
	}

	// Compliant input
	body = `{
		"message": {
			"order": {
				"items": [
					{"id": "item1", "quantity": {"count": 3}}
				]
			}
		}
	}`
	violations, err = eval.Evaluate(context.Background(), []byte(body))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations for compliant input, got %v", violations)
	}
}

func TestEvaluator_StructuredResult_FalseNoViolations(t *testing.T) {
	// Edge case: valid=false but violations is empty — should report generic denial
	policy := `
package policy

import rego.v1

result := {
  "valid": false,
  "violations": []
}
`
	dir := writePolicyDir(t, "policy.rego", policy)
	eval, err := NewEvaluator([]string{dir}, "data.policy.result", nil, false)
	if err != nil {
		t.Fatalf("NewEvaluator failed: %v", err)
	}

	violations, err := eval.Evaluate(context.Background(), []byte(`{}`))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 || violations[0] != "policy denied the request" {
		t.Errorf("expected ['policy denied the request'], got %v", violations)
	}
}

// --- Bundle Tests ---

// buildTestBundle creates an OPA bundle .tar.gz in memory from the given modules.
func buildTestBundle(t *testing.T, modules map[string]string) []byte {
	t.Helper()
	b := bundle.Bundle{
		Modules: make([]bundle.ModuleFile, 0, len(modules)),
		Data:    make(map[string]interface{}),
	}
	for path, content := range modules {
		b.Modules = append(b.Modules, bundle.ModuleFile{
			URL:    path,
			Path:   path,
			Raw:    []byte(content),
			Parsed: nil,
		})
	}

	var buf bytes.Buffer
	if err := bundle.Write(&buf, b); err != nil {
		t.Fatalf("failed to write test bundle: %v", err)
	}
	return buf.Bytes()
}

func TestEvaluator_BundleFromURL(t *testing.T) {
	policy := `
package retail.validation

import rego.v1

default result := {
  "valid": true,
  "violations": []
}

result := {
  "valid": count(violations) == 0,
  "violations": violations
}

violations contains msg if {
  some item in input.message.order.items
  item.quantity.count <= 0
  msg := sprintf("item %s: quantity must be > 0", [item.id])
}
`
	bundleData := buildTestBundle(t, map[string]string{
		"retail/validation.rego": policy,
	})

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/gzip")
		w.Write(bundleData)
	}))
	defer srv.Close()

	eval, err := NewEvaluator([]string{srv.URL + "/bundle.tar.gz"}, "data.retail.validation.result", nil, true)
	if err != nil {
		t.Fatalf("NewEvaluator with bundle failed: %v", err)
	}

	// Non-compliant
	body := `{"message":{"order":{"items":[{"id":"x","quantity":{"count":0}}]}}}`
	violations, err := eval.Evaluate(context.Background(), []byte(body))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 1 {
		t.Fatalf("expected 1 violation, got %d: %v", len(violations), violations)
	}

	// Compliant
	body = `{"message":{"order":{"items":[{"id":"x","quantity":{"count":5}}]}}}`
	violations, err = eval.Evaluate(context.Background(), []byte(body))
	if err != nil {
		t.Fatalf("Evaluate failed: %v", err)
	}
	if len(violations) != 0 {
		t.Errorf("expected 0 violations, got %v", violations)
	}
}

func TestEnforcer_BundlePolicy(t *testing.T) {
	policy := `
package retail.policy

import rego.v1

default result := {
  "valid": true,
  "violations": []
}

result := {
  "valid": count(violations) == 0,
  "violations": violations
}

violations contains "blocked" if {
  input.context.action == "confirm"
  not input.message.order.provider
}
`
	bundleData := buildTestBundle(t, map[string]string{
		"retail/policy.rego": policy,
	})

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/gzip")
		w.Write(bundleData)
	}))
	defer srv.Close()

	enforcer, err := New(context.Background(), map[string]string{
		"type":     "bundle",
		"location": srv.URL + "/policy-bundle.tar.gz",
		"query":    "data.retail.policy.result",
		"actions":  "confirm",
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	// Non-compliant: confirm without provider
	ctx := makeStepCtx("confirm", `{"context": {"action": "confirm"}, "message": {"order": {}}}`)
	err = enforcer.CheckPolicy(ctx)
	if err == nil {
		t.Fatal("expected error for non-compliant message, got nil")
	}
	if _, ok := err.(*model.BadReqErr); !ok {
		t.Errorf("expected *model.BadReqErr, got %T: %v", err, err)
	}

	// Compliant: confirm with provider
	ctx = makeStepCtx("confirm", `{"context": {"action": "confirm"}, "message": {"order": {"provider": {"id": "p1"}}}}`)
	err = enforcer.CheckPolicy(ctx)
	if err != nil {
		t.Errorf("expected nil error for compliant message, got: %v", err)
	}
}

func TestParseConfig_RefreshInterval(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":                   "dir",
		"location":               "/tmp",
		"query":                  "data.policy.violations",
		"refreshIntervalSeconds": "300",
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if cfg.RefreshInterval != 300*time.Second {
		t.Errorf("expected 300s refresh interval, got %v", cfg.RefreshInterval)
	}
}

func TestParseConfig_RefreshInterval_Zero(t *testing.T) {
	cfg, err := ParseConfig(map[string]string{
		"type":     "dir",
		"location": "/tmp",
		"query":    "data.policy.violations",
		// no refreshIntervalSeconds → disabled
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if cfg.RefreshInterval != 0 {
		t.Errorf("expected refresh disabled (0), got %v", cfg.RefreshInterval)
	}
}

func TestParseConfig_RefreshInterval_Invalid(t *testing.T) {
	_, err := ParseConfig(map[string]string{
		"type":                   "dir",
		"location":               "/tmp",
		"query":                  "data.policy.violations",
		"refreshIntervalSeconds": "not-a-number",
	})
	if err == nil {
		t.Fatal("expected error for invalid refreshIntervalSeconds")
	}
}

// TestEnforcer_HotReload verifies that the hot-reload goroutine picks up changes
// to a local policy file within the configured refresh interval.
func TestEnforcer_HotReload(t *testing.T) {
	dir := t.TempDir()
	policyPath := filepath.Join(dir, "policy.rego")

	// Initial policy: always blocks confirm
	blockPolicy := `package policy
import rego.v1
default result := {"valid": false, "violations": ["blocked by initial policy"]}
result := {"valid": false, "violations": ["blocked by initial policy"]}
`
	if err := os.WriteFile(policyPath, []byte(blockPolicy), 0644); err != nil {
		t.Fatalf("failed to write initial policy: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	enforcer, err := New(ctx, map[string]string{
		"type":                   "dir",
		"location":               dir,
		"query":                  "data.policy.result",
		"refreshIntervalSeconds": "1", // 1s refresh for test speed
	})
	if err != nil {
		t.Fatalf("New failed: %v", err)
	}

	// Confirm is blocked with initial policy
	stepCtx := makeStepCtx("confirm", `{"context":{"action":"confirm"}}`)
	if err := enforcer.CheckPolicy(stepCtx); err == nil {
		t.Fatal("expected block from initial policy, got nil")
	}

	// Swap policy on disk to allow everything
	allowPolicy := `package policy
import rego.v1
default result := {"valid": true, "violations": []}
`
	if err := os.WriteFile(policyPath, []byte(allowPolicy), 0644); err != nil {
		t.Fatalf("failed to write updated policy: %v", err)
	}

	// Wait up to 5s for the reload to fire and swap the evaluator
	deadline := time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		if err := enforcer.CheckPolicy(stepCtx); err == nil {
			// Reload took effect
			return
		}
		time.Sleep(200 * time.Millisecond)
	}

	t.Fatal("hot-reload did not take effect within 5 seconds")
}