package controller

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"time"

	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/log"

	forgebotv1alpha1 "git.unkin.net/unkin/forgebot/api/v1alpha1"
	"git.unkin.net/unkin/forgebot/pkg/models"
)

type ProviderQueueReconciler struct {
	client.Client
	Scheme     *runtime.Scheme
	HTTPClient *http.Client
}

// +kubebuilder:rbac:groups=forgebot.unkin.net,resources=providerqueues,verbs=get;list;watch;update;patch
// +kubebuilder:rbac:groups=forgebot.unkin.net,resources=providerqueues/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=forgebot.unkin.net,resources=agenttasks,verbs=create
// +kubebuilder:rbac:groups=forgebot.unkin.net,resources=repositorybindings,verbs=get;list;watch

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

	var queue forgebotv1alpha1.ProviderQueue
	if err := r.Get(ctx, req.NamespacedName, &queue); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	pollInterval, err := time.ParseDuration(queue.Spec.PollInterval)
	if err != nil {
		pollInterval = 30 * time.Second
	}

	httpClient := r.HTTPClient
	if httpClient == nil {
		httpClient = &http.Client{Timeout: 10 * time.Second}
	}

	resp, err := httpClient.Get(queue.Spec.Endpoint + "/tasks?status=pending")
	if err != nil {
		now := metav1.Now()
		queue.Status.LastPoll = &now
		queue.Status.LastError = err.Error()
		_ = r.Status().Update(ctx, &queue)
		logger.Error(err, "failed to poll API")
		return ctrl.Result{RequeueAfter: pollInterval}, nil
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return ctrl.Result{RequeueAfter: pollInterval}, err
	}

	var tasks []models.Task
	if err := json.Unmarshal(body, &tasks); err != nil {
		return ctrl.Result{RequeueAfter: pollInterval}, err
	}

	var bindings forgebotv1alpha1.RepositoryBindingList
	if err := r.List(ctx, &bindings, client.InNamespace(req.Namespace)); err != nil {
		return ctrl.Result{RequeueAfter: pollInterval}, err
	}

	bindingMap := map[string]*forgebotv1alpha1.RepositoryBinding{}
	for i := range bindings.Items {
		b := &bindings.Items[i]
		if b.Spec.ProviderQueueRef == queue.Name {
			bindingMap[b.Spec.Repository] = b
		}
	}

	for _, task := range tasks {
		binding, ok := bindingMap[task.Repository]
		if !ok {
			continue
		}

		if !isAllowed(binding, task.Author, task.Command) {
			continue
		}

		agentTask := &forgebotv1alpha1.AgentTask{
			ObjectMeta: metav1.ObjectMeta{
				Name:      fmt.Sprintf("task-%s", task.ID[:8]),
				Namespace: req.Namespace,
			},
			Spec: forgebotv1alpha1.AgentTaskSpec{
				PoolRef:    binding.Spec.AgentPoolRef,
				Command:    task.Command,
				Skill:      resolveSkill(binding, task.Command),
				Repository: task.Repository,
				Ref:        task.Ref,
				Context: forgebotv1alpha1.TaskContext{
					IssueNumber: task.IssueNumber,
					PRNumber:    task.PRNumber,
					CommentID:   task.CommentID,
					Body:        task.Body,
					Author:      task.Author,
				},
				ExtraTools:    task.ExtraTools,
				ParentTaskRef: task.ParentTaskID,
			},
		}

		if err := r.Create(ctx, agentTask); err != nil {
			logger.Error(err, "failed to create AgentTask", "task", task.ID)
			continue
		}

		queue.Status.TasksCreated++
		logger.Info("created AgentTask", "task", agentTask.Name, "command", task.Command)
	}

	now := metav1.Now()
	queue.Status.LastPoll = &now
	queue.Status.LastError = ""
	_ = r.Status().Update(ctx, &queue)

	return ctrl.Result{RequeueAfter: pollInterval}, nil
}

func isAllowed(binding *forgebotv1alpha1.RepositoryBinding, author, command string) bool {
	if len(binding.Spec.AllowedUsers) > 0 {
		found := false
		for _, u := range binding.Spec.AllowedUsers {
			if u == author {
				found = true
				break
			}
		}
		if !found {
			return false
		}
	}
	if len(binding.Spec.AllowedCommands) > 0 {
		for _, c := range binding.Spec.AllowedCommands {
			if c == command {
				return true
			}
		}
		return false
	}
	return true
}

func resolveSkill(binding *forgebotv1alpha1.RepositoryBinding, command string) string {
	for _, m := range binding.Spec.SkillMapping {
		if m.Command == command {
			return m.Skill
		}
	}
	return command
}

func (r *ProviderQueueReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&forgebotv1alpha1.ProviderQueue{}).
		Complete(r)
}