package main

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

	"git.cin.su/m/Assistant/contracts/authority"
	"git.cin.su/m/Assistant/contracts/capability"
	"git.cin.su/m/Assistant/contracts/identity"
	"git.cin.su/m/Assistant/platform/ids"
)

type delegatedAuthorityFake struct {
	grant   authority.DelegatedControlPlaneGrant
	audits  []authority.DelegatedControlPlaneAudit
	revoked bool
}

func TestCandidateBindingResolutionUsesServiceCredential(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/internal/capability-bindings/candidate/resolve" || r.Header.Get("Authorization") != "Bearer service-token" {
			t.Fatalf("unexpected candidate resolution request: %s %q", r.URL.Path, r.Header.Get("Authorization"))
		}
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"reason":"EXACT_CONTEXT"}`))
	}))
	defer server.Close()
	client, err := newCreatorCoreClient(server.URL, server.Client())
	if err != nil {
		t.Fatal(err)
	}
	client.serviceCredential = func() (string, error) { return "service-token", nil }
	if _, err := client.ResolveCandidateCapabilityBinding(context.Background(), capability.CandidateReleaseContext{}); err != nil {
		t.Fatalf("resolve candidate binding: %v", err)
	}
}

func TestDelegatedAuthorityCredentialRotationRejectsOldToken(t *testing.T) {
	root := t.TempDir()
	tokenPath := filepath.Join(root, "control_plane_service_token")
	if err := os.WriteFile(tokenPath, []byte("old-token\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("CONTROL_PLANE_SERVICE_CREDENTIAL_REF", "credential://domovoy/control-plane/service-token/v1")
	t.Setenv("CONTROL_PLANE_SERVICE_SECRET_ROOT", root)
	h := delegatedControlPlaneHandler{credential: delegatedControlPlaneCredential}
	oldRequest := httptest.NewRequest(http.MethodPost, "/v1/internal/control-plane/authorize", nil)
	oldRequest.Header.Set("Authorization", "Bearer old-token")
	if !h.serviceAuthenticated(oldRequest) {
		t.Fatal("active credential was rejected before rotation")
	}
	if err := os.WriteFile(tokenPath, []byte("new-token\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	if h.serviceAuthenticated(oldRequest) {
		t.Fatal("old credential remained valid after rotation")
	}
	newRequest := httptest.NewRequest(http.MethodPost, "/v1/internal/control-plane/authorize", nil)
	newRequest.Header.Set("Authorization", "Bearer new-token")
	if !h.serviceAuthenticated(newRequest) {
		t.Fatal("new credential was rejected after rotation")
	}
}

func (f *delegatedAuthorityFake) LoadDelegatedControlPlaneGrant(context.Context, authority.GrantID) (authority.DelegatedControlPlaneGrant, error) {
	if f.grant.ID == "" {
		return authority.DelegatedControlPlaneGrant{}, errors.New("missing")
	}
	return f.grant, nil
}
func (f *delegatedAuthorityFake) RecordDelegatedControlPlaneAudit(_ context.Context, audit authority.DelegatedControlPlaneAudit) error {
	f.audits = append(f.audits, audit)
	return nil
}
func (f *delegatedAuthorityFake) RevokeDelegatedControlPlaneGrant(context.Context, authority.GrantID, string) (bool, error) {
	f.revoked = true
	f.grant.Status = authority.DelegatedGrantRevoked
	return true, nil
}

type delegatedCoreFake struct{}

func (delegatedCoreFake) Binding(context.Context, identity.ActorID, identity.PrincipalID) (identity.PrincipalBinding, error) {
	return identity.PrincipalBinding{ActorID: delegatedControlPlaneActor, PrincipalID: delegatedControlPlanePrincipal, Active: true}, nil
}
func (delegatedCoreFake) Session(context.Context, string) (identity.CreatorSession, error) {
	return identity.CreatorSession{PrincipalID: "owner"}, nil
}

func TestDelegatedAuthorityRejectsWrongResourceAndSurvivesRestart(t *testing.T) {
	resource := authority.CognitiveBindingResource{BindingID: "binding", ProviderInstanceID: "provider", ModelDescriptorID: "model"}
	fake := &delegatedAuthorityFake{grant: authority.DelegatedControlPlaneGrant{ID: "grant", ServiceActorID: delegatedControlPlaneActor, ServicePrincipalID: delegatedControlPlanePrincipal, IssuerPrincipalID: "owner", TaskID: "GEN2-COGNITIVE-003", TaskRevision: 4, Operations: []authority.DelegatedControlPlaneOperation{authority.DelegatedOperationCanaryCognitiveBinding}, Resource: resource, IssuedAtUnixMillis: 1, ExpiresAtUnixMillis: 100, ArchitectureRevision: "ADR-0021", Nonce: "nonce", Revision: 1, Status: authority.DelegatedGrantActive}}
	h := delegatedControlPlaneHandler{authority: fake, core: delegatedCoreFake{}, credential: func() (string, error) { return "service-token", nil }, now: func() time.Time { return time.UnixMilli(10) }, newID: func() (ids.ID, error) { return "audit", nil }}
	mux := http.NewServeMux()
	registerDelegatedControlPlaneRoutes(mux, h)
	valid := `{"GrantID":"grant","TaskID":"GEN2-COGNITIVE-003","TaskRevision":4,"Operation":"CANARY_COGNITIVE_BINDING","Resource":{"BindingID":"binding","ProviderInstanceID":"provider","ModelDescriptorID":"model"}}`
	request := httptest.NewRequest(http.MethodPost, "/v1/internal/control-plane/authorize", strings.NewReader(valid))
	request.Header.Set("Authorization", "Bearer service-token")
	response := httptest.NewRecorder()
	mux.ServeHTTP(response, request)
	if response.Code != http.StatusNoContent {
		t.Fatalf("valid delegation status=%d", response.Code)
	}
	wrong := strings.Replace(valid, `"binding"`, `"other"`, 1)
	request = httptest.NewRequest(http.MethodPost, "/v1/internal/control-plane/authorize", strings.NewReader(wrong))
	request.Header.Set("Authorization", "Bearer service-token")
	response = httptest.NewRecorder()
	mux.ServeHTTP(response, request)
	if response.Code != http.StatusForbidden {
		t.Fatalf("wrong resource status=%d", response.Code)
	}
	// A fresh handler reads the same durable grant source; no process-local allow survives restart.
	request = httptest.NewRequest(http.MethodPost, "/v1/creator/control-plane/grants/grant/revoke", nil)
	request.Header.Set("Authorization", "Bearer creator-session")
	response = httptest.NewRecorder()
	mux.ServeHTTP(response, request)
	if response.Code != http.StatusNoContent || !fake.revoked {
		t.Fatalf("revoke status=%d revoked=%v", response.Code, fake.revoked)
	}
	restarted := delegatedControlPlaneHandler{authority: fake, core: delegatedCoreFake{}, credential: h.credential, now: h.now, newID: h.newID}
	mux = http.NewServeMux()
	registerDelegatedControlPlaneRoutes(mux, restarted)
	request = httptest.NewRequest(http.MethodPost, "/v1/internal/control-plane/authorize", strings.NewReader(valid))
	request.Header.Set("Authorization", "Bearer service-token")
	response = httptest.NewRecorder()
	mux.ServeHTTP(response, request)
	if response.Code != http.StatusForbidden {
		t.Fatalf("revoked grant accepted after restart: %d", response.Code)
	}
	if len(fake.audits) < 3 {
		t.Fatalf("audit trail missing: %#v", fake.audits)
	}
}