/*
Copyright 2026 LocoStack.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package controller

import (
	"context"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	apimeta "k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	logf "sigs.k8s.io/controller-runtime/pkg/log"

	"github.com/LocoStack/loco-operator/api/v1alpha1"
	"github.com/LocoStack/loco-operator/internal/reconciler"
)

// ExternalModelReconciler reconciles a ExternalModel object
type ExternalModelReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

// +kubebuilder:rbac:groups=locostack.com,resources=externalmodels,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=locostack.com,resources=externalmodels/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=locostack.com,resources=externalmodels/finalizers,verbs=update
// +kubebuilder:rbac:groups=locostack.com,resources=components,verbs=get;list;watch
// +kubebuilder:rbac:groups="",resources=secrets,verbs=get;list;watch

func (r *ExternalModelReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	log := logf.FromContext(ctx)

	em := &v1alpha1.ExternalModel{}
	if err := r.Get(ctx, req.NamespacedName, em); err != nil {
		if apierrors.IsNotFound(err) {
			return ctrl.Result{}, nil
		}
		log.Error(err, "Failed to get ExternalModel", "namespace", req.NamespacedName.Namespace, "name", req.NamespacedName.Name)
		return ctrl.Result{}, err
	}

	patch := client.MergeFrom(em.DeepCopy())

	gatewayBound, err := r.reconcileGatewayStatus(ctx, em)
	if err != nil {
		log.Error(err, "Failed to reconcile gateway status for ExternalModel", "namespace", req.NamespacedName.Namespace, "name", req.NamespacedName.Name)
		return ctrl.Result{}, err
	}
	credentialsResolved, err := r.reconcileCredentials(ctx, em)
	if err != nil {
		log.Error(err, "Failed to reconcile credentials for ExternalModel", "namespace", req.NamespacedName.Namespace, "name", req.NamespacedName.Name)
		return ctrl.Result{}, err
	}

	if gatewayBound && credentialsResolved {
		apimeta.SetStatusCondition(&em.Status.Conditions, metav1.Condition{
			Type:               "Ready",
			Status:             metav1.ConditionTrue,
			Reason:             "AllPreconditionsMet",
			Message:            "Gateway exists and credentials resolve",
			ObservedGeneration: em.Generation,
		})
	} else {
		apimeta.SetStatusCondition(&em.Status.Conditions, metav1.Condition{
			Type:               "Ready",
			Status:             metav1.ConditionFalse,
			Reason:             "PreconditionsNotMet",
			Message:            "Gateway not found or credentials not resolved",
			ObservedGeneration: em.Generation,
		})
	}

	em.Status.ObservedGeneration = em.Generation
	if err := r.Status().Patch(ctx, em, patch); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	log.Info("Reconciled ExternalModel", "namespace", em.Namespace, "name", em.Name)
	return ctrl.Result{}, nil
}

func (r *ExternalModelReconciler) reconcileGatewayStatus(ctx context.Context, em *v1alpha1.ExternalModel) (bool, error) {
	condition, err := reconciler.ReconcileGatewayStatus(ctx, r.Client, r.Scheme, em.Spec.StackRef.Name, em)
	if err != nil {
		return false, err
	}
	apimeta.SetStatusCondition(&em.Status.Conditions, *condition)
	return condition.Status == metav1.ConditionTrue, nil
}

func (r *ExternalModelReconciler) reconcileCredentials(ctx context.Context, em *v1alpha1.ExternalModel) (bool, error) {
	condition, err := reconciler.ReconcileCredentials(ctx, r.Client, r.Scheme, em.Spec.Auth, em)
	if err != nil {
		return false, err
	}
	apimeta.SetStatusCondition(&em.Status.Conditions, *condition)
	return condition.Status == metav1.ConditionTrue, nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *ExternalModelReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&v1alpha1.ExternalModel{}).
		Watches(&v1alpha1.Component{}, ComponentEventHandler("ExternalModel")).
		Named("externalmodel").
		Complete(r)
}