/*
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"
	"encoding/json"
	"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"
)

// SkillReconciler reconciles a Skill object
type SkillReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

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

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

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

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

	skillAvailable, files, err := r.reconcileSkillConfigMap(ctx, sk)
	if err != nil {
		return ctrl.Result{}, err
	}

	if !skillAvailable {
		apimeta.SetStatusCondition(&sk.Status.Conditions, metav1.Condition{
			Type:               "Available",
			Status:             metav1.ConditionFalse,
			Reason:             "SkillUnavailable",
			Message:            "Skill is not available",
			ObservedGeneration: sk.Generation,
		})
	} else {
		apimeta.SetStatusCondition(&sk.Status.Conditions, metav1.Condition{
			Type:               "Available",
			Status:             metav1.ConditionTrue,
			Reason:             "SkillAvailable",
			Message:            "Skill is available",
			ObservedGeneration: sk.Generation,
		})
	}

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

	return ctrl.Result{}, nil
}

func (r *SkillReconciler) reconcileSkillConfigMap(ctx context.Context, sk *v1alpha1.Skill) (bool, int32, error) {
	files := int32(1)
	skillMD := fmt.Sprintf(`---
name: %s
description: %s.
---

%s`, sk.Name, sk.Spec.Description, sk.Spec.Body)
	cmData := map[string]string{
		v1alpha1.SkillConfigMapKey("SKILL.md"): skillMD,
	}
	filePaths := map[string]string{
		v1alpha1.SkillConfigMapKey("SKILL.md"): "SKILL.md",
	}
	for _, fileEntry := range sk.Spec.Files {
		key := v1alpha1.SkillConfigMapKey(fileEntry.Path)
		cmData[key] = fileEntry.Content
		filePaths[key] = fileEntry.Path
		files++
	}
	filePathsJSON, err := json.Marshal(filePaths)
	if err != nil {
		return false, 0, fmt.Errorf("marshaling skill file paths for %s: %w", sk.Name, err)
	}

	cm := &corev1.ConfigMap{ObjectMeta: metav1.ObjectMeta{Name: sk.Name, Namespace: sk.Namespace}}
	_, err = controllerutil.CreateOrUpdate(ctx, r.Client, cm, func() error {
		if cm.Labels == nil {
			cm.Labels = make(map[string]string)
		}
		stackName := ""
		if sk.Spec.StackRef != nil {
			stackName = sk.Spec.StackRef.Name
		}
		maps.Copy(cm.Labels, reconciler.ResourceLabels(stackName, "Skill", sk.Name, ""))
		if cm.Annotations == nil {
			cm.Annotations = make(map[string]string)
		}
		cm.Annotations[v1alpha1.SkillFilePathsAnnotation] = string(filePathsJSON)
		cm.Data = cmData
		return controllerutil.SetControllerReference(sk, cm, r.Scheme)
	})

	return err == nil, files, err
}

// SetupWithManager sets up the controller with the Manager.
func (r *SkillReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&v1alpha1.Skill{}).
		Owns(&corev1.ConfigMap{}).
		Named("skill").
		Complete(r)
}