package porter_app

import (
	"net/http"
	"strings"

	"github.com/porter-dev/porter/api/server/authz"
	"github.com/porter-dev/porter/api/server/handlers"
	"github.com/porter-dev/porter/api/server/shared"
	"github.com/porter-dev/porter/api/server/shared/apierrors"
	"github.com/porter-dev/porter/api/server/shared/config"
	"github.com/porter-dev/porter/api/server/shared/requestutils"
	"github.com/porter-dev/porter/api/types"
	utils "github.com/porter-dev/porter/api/utils/porter_app"
	"github.com/porter-dev/porter/internal/kubernetes/porter_app"
	"github.com/porter-dev/porter/internal/models"
	"github.com/porter-dev/porter/internal/telemetry"
)

// RunPorterAppCommandHandler runs a command on a porter app
type RunPorterAppCommandHandler struct {
	handlers.PorterHandlerReadWriter
	authz.KubernetesAgentGetter
}

// NewRunPorterAppCommandHandler returns a new RunPorterAppCommandHandler
func NewRunPorterAppCommandHandler(
	config *config.Config,
	decoderValidator shared.RequestDecoderValidator,
	writer shared.ResultWriter,
) *RunPorterAppCommandHandler {
	return &RunPorterAppCommandHandler{
		PorterHandlerReadWriter: handlers.NewDefaultPorterHandler(config, decoderValidator, writer),
		KubernetesAgentGetter:   authz.NewOutOfClusterAgentGetter(config),
	}
}

func (c *RunPorterAppCommandHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	cluster, _ := ctx.Value(types.ClusterScope).(*models.Cluster)

	ctx, span := telemetry.NewSpan(r.Context(), "serve-run-porter-app-command")
	defer span.End()

	request := &types.RunPorterAppCommandRequest{}
	if ok := c.DecodeAndValidate(w, r, request); !ok {
		err := telemetry.Error(ctx, span, nil, "error decoding request")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
		return
	}

	appName, reqErr := requestutils.GetURLParamString(r, types.URLParamPorterAppName)
	if reqErr != nil {
		err := telemetry.Error(ctx, span, reqErr, "error getting app name from url")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
		return
	}
	namespace := utils.NamespaceFromPorterAppName(appName)
	telemetry.WithAttributes(span, telemetry.AttributeKV{Key: "application-name", Value: appName})

	app, err := c.Repo().PorterApp().ReadPorterAppByName(cluster.ID, appName)
	if err != nil {
		err = telemetry.Error(ctx, span, err, "error reading app from DB")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}
	if app == nil {
		err = telemetry.Error(ctx, span, nil, "app with name does not exist in project")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusForbidden))
		return
	}

	k8sAgent, err := c.GetAgent(r, cluster, namespace)
	if err != nil {
		err = telemetry.Error(ctx, span, err, "error getting k8s agent")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	podList, err := k8sAgent.GetPodsByLabel(porter_app.LabelKey_PorterApplication, namespace)
	if err != nil {
		err = telemetry.Error(ctx, span, err, "error getting pods by label")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	if len(podList.Items) == 0 {
		err = telemetry.Error(ctx, span, err, "no pods found to run command on")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	selectedPod := podList.Items[0]
	execArgs := strings.Split(request.Command, " ")
	if app.Builder != "" &&
		(strings.Contains(app.Builder, "heroku") ||
			strings.Contains(app.Builder, "paketo")) &&
		execArgs[0] != "/cnb/lifecycle/launcher" &&
		execArgs[0] != "launcher" {
		// this is a buildpacks release using a heroku builder, so we prepend commands with launcher command
		execArgs = append([]string{"/cnb/lifecycle/launcher"}, execArgs...)
	}

	err = k8sAgent.RunCommandOnPod(ctx, &selectedPod, execArgs)
	if err != nil {
		err = telemetry.Error(ctx, span, err, "error running command on pod")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}
}