package api_contract

import (
	"encoding/base64"
	"errors"
	"fmt"
	"net/http"

	"github.com/nats-io/nats.go"
	helpers "github.com/porter-dev/api-contracts/generated/go/helpers"
	porterv1 "github.com/porter-dev/api-contracts/generated/go/porter/v1"
	"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/types"
	"github.com/porter-dev/porter/internal/models"
)

type APIContractUpdateHandler struct {
	handlers.PorterHandlerReadWriter
}

func NewAPIContractUpdateHandler(
	config *config.Config,
	decoderValidator shared.RequestDecoderValidator,
	writer shared.ResultWriter,
) *APIContractUpdateHandler {
	return &APIContractUpdateHandler{
		PorterHandlerReadWriter: handlers.NewDefaultPorterHandler(config, decoderValidator, writer),
	}
}

// ServeHTTP parses the Porter API contract for validity, and forwards the requests for handling on to another service
// For now, this handling cluster creation only, by inserting a row into the cluster table in order to create an ID for this cluster, as well as stores the raw request JSON for updating later
func (c *APIContractUpdateHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	var apiContract porterv1.Contract

	err := helpers.UnmarshalContractObjectFromReader(r.Body, &apiContract)
	if err != nil {
		e := fmt.Errorf("error parsing api contract: %w", err)
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}

	if apiContract.Cluster == nil {
		e := errors.New("missing cluster object")
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}

	cl := apiContract.Cluster

	if cl.CloudProviderCredentialsId == "" {
		e := errors.New("missing cloud_provider_credential_identifier")
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}

	if cl.GetEksKind() == nil {
		e := errors.New("missing eks_kind_values")
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}

	if cl.ClusterId == 0 {
		dbClusterInput := models.Cluster{
			ProjectID:                         uint(cl.ProjectId),
			Status:                            types.UpdatingUnavailable,
			ProvisionedBy:                     "CAPI",
			CloudProvider:                     "AWS",
			CloudProviderCredentialIdentifier: cl.CloudProviderCredentialsId,
			Name:                              cl.GetEksKind().ClusterName,
			VanityName:                        cl.GetEksKind().ClusterName,
		}
		dbCluster, err := c.Config().Repo.Cluster().CreateCluster(&dbClusterInput)
		if err != nil {
			e := fmt.Errorf("error creating new cluster: %w", err)
			c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
			return
		}
		apiContract.Cluster.ClusterId = int32(dbCluster.ID)
	}

	by, err := helpers.MarshalContractObject(ctx, &apiContract)
	if err != nil {
		e := fmt.Errorf("error marshalling api contract: %w", err)
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}
	b64 := base64.StdEncoding.EncodeToString([]byte(by))

	apiContractRevision := models.APIContractRevision{
		ClusterID:      int(cl.ClusterId),
		ProjectID:      int(cl.ProjectId),
		Base64Contract: string(b64),
	}

	contractRevision, err := c.Config().Repo.APIContractRevisioner().Insert(ctx, apiContractRevision)
	if err != nil {
		e := fmt.Errorf("error creating new capi config: %w", err)
		c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
		return
	}

	// This gates the cluster actually being provisioned by CAPI
	// This can be removed whenever we are able to run NATS and CCP locally, easier
	if !c.Config().DisableCAPIProvisioner {
		resp := porterv1.ContractRevision{
			ProjectId:  cl.ProjectId,
			ClusterId:  cl.ClusterId,
			RevisionId: contractRevision.ID.String(),
		}
		kubeBy, err := helpers.MarshalContractObject(ctx, &resp)
		if err != nil {
			e := fmt.Errorf("error marshalling api contract: %w", err)
			c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
			return
		}
		subject := "porter.system.infrastructure.update"
		_, err = c.Config().NATS.JetStream.Publish(subject, kubeBy, nats.Context(ctx))
		if err != nil {
			e := fmt.Errorf("error publishing cluster for creation: %w", err)
			c.HandleAPIError(w, r, apierrors.NewErrInternal(e))
			return
		}
	}

	w.WriteHeader(http.StatusCreated)
	c.WriteResult(w, r, contractRevision)
}