/*
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"
	"fmt"
	"maps"

	corev1 "k8s.io/api/core/v1"
	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"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	logf "sigs.k8s.io/controller-runtime/pkg/log"

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

// ManagedToolReconciler reconciles a ManagedTool object
type ManagedToolReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

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

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

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

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

	componentAvailable, err := r.reconcileComponent(ctx, mt)
	if err != nil {
		return ctrl.Result{}, err
	}
	gatewayBound, err := r.reconcileGatewayStatus(ctx, mt)
	if err != nil {
		log.Error(err, "Failed to reconcile gateway status for ManagedTool", "namespace", req.NamespacedName.Namespace, "name", req.NamespacedName.Name)
		return ctrl.Result{}, err
	}
	if !componentAvailable {
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "Available",
			Status:             metav1.ConditionFalse,
			Reason:             "ToolUnavailable",
			Message:            "ManagedTool is not available",
			ObservedGeneration: mt.Generation,
		})
	} else if !gatewayBound {
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "Available",
			Status:             metav1.ConditionFalse,
			Reason:             "GatewayUnbound",
			Message:            "ManagedTool is not bound to a gateway",
			ObservedGeneration: mt.Generation,
		})
	} else {
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "Available",
			Status:             metav1.ConditionTrue,
			Reason:             "ToolAvailable",
			Message:            "ManagedTool is available",
			ObservedGeneration: mt.Generation,
		})
	}

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

	log.Info("Reconciled ManagedTool", "namespace", req.NamespacedName.Namespace, "name", req.NamespacedName.Name)
	return ctrl.Result{}, nil
}

func (r *ManagedToolReconciler) reconcileComponent(ctx context.Context, mt *v1alpha1.ManagedTool) (bool, error) {
	compName := fmt.Sprintf("tool-%s", mt.Name)
	comp := &v1alpha1.Component{
		ObjectMeta: metav1.ObjectMeta{
			Name:      compName,
			Namespace: mt.Namespace,
		},
	}
	err := r.Get(ctx, client.ObjectKey{Namespace: mt.Namespace, Name: compName}, comp)

	tmpl, err := templates.Manager.ResolveTemplate(mt.Spec.Template, "")
	if err != nil {
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "ToolRuntimeResolved",
			Status:             metav1.ConditionFalse,
			Reason:             "TemplateNotResolved",
			Message:            fmt.Sprintf("Failed to reconcile template for ManagedTool: %v", err),
			ObservedGeneration: mt.Generation,
		})
		return false, nil
	}
	apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
		Type:               "ToolRuntimeResolved",
		Status:             metav1.ConditionTrue,
		Reason:             "TemplateResolved",
		Message:            fmt.Sprintf("Successfully resolved template for ManagedTool: %v", tmpl.Name),
		ObservedGeneration: mt.Generation,
	})

	_, err = controllerutil.CreateOrUpdate(ctx, r.Client, comp, func() error {
		if comp.Labels == nil {
			comp.Labels = make(map[string]string)
		}
		stackName := ""
		if mt.Spec.StackRef != nil {
			stackName = mt.Spec.StackRef.Name
		}
		maps.Copy(comp.Labels, reconciler.ResourceLabels(stackName, "Tool", mt.Name, ""))
		comp.Spec.Category = "Tool"
		comp.Spec.Template = &tmpl
		if mt.Spec.StackRef != nil {
			comp.Spec.StackRef = &corev1.LocalObjectReference{Name: mt.Spec.StackRef.Name}
		}
		return controllerutil.SetControllerReference(mt, comp, r.Scheme)
	})

	available := apimeta.IsStatusConditionTrue(comp.Status.Conditions, "Available")
	if available {
		mt.Status.Endpoint = comp.Status.Endpoint
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "Ready",
			Status:             metav1.ConditionTrue,
			Reason:             "ComponentAvailable",
			Message:            "Component is available",
			ObservedGeneration: mt.Generation,
		})
	} else {
		apimeta.SetStatusCondition(&mt.Status.Conditions, metav1.Condition{
			Type:               "Ready",
			Status:             metav1.ConditionFalse,
			Reason:             "ComponentUnavailable",
			Message:            "Component is not available",
			ObservedGeneration: mt.Generation,
		})
	}
	return available, err
}

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

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