package porter_app

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

	"connectrpc.com/connect"

	porterv1 "github.com/porter-dev/api-contracts/generated/go/porter/v1"

	"github.com/porter-dev/api-contracts/generated/go/helpers"

	"github.com/porter-dev/porter/internal/deployment_target"
	"github.com/porter-dev/porter/internal/porter_app"
	v2 "github.com/porter-dev/porter/internal/porter_app/v2"
	"github.com/porter-dev/porter/internal/telemetry"

	"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/types"
	"github.com/porter-dev/porter/internal/models"
)

// ApplyPorterAppHandler is the handler for the /apps/parse endpoint
type ApplyPorterAppHandler struct {
	handlers.PorterHandlerReadWriter
	authz.KubernetesAgentGetter
}

// NewApplyPorterAppHandler handles POST requests to the endpoint /apps/apply
func NewApplyPorterAppHandler(
	config *config.Config,
	decoderValidator shared.RequestDecoderValidator,
	writer shared.ResultWriter,
) *ApplyPorterAppHandler {
	return &ApplyPorterAppHandler{
		PorterHandlerReadWriter: handlers.NewDefaultPorterHandler(config, decoderValidator, writer),
		KubernetesAgentGetter:   authz.NewOutOfClusterAgentGetter(config),
	}
}

// ApplyPorterAppRequest is the request object for the /apps/apply endpoint
type ApplyPorterAppRequest struct {
	Base64AppProto     string `json:"b64_app_proto"`
	DeploymentTargetId string `json:"deployment_target_id"`
	AppRevisionID      string `json:"app_revision_id"`
	ForceBuild         bool   `json:"force_build"`
}

// ApplyPorterAppResponse is the response object for the /apps/apply endpoint
type ApplyPorterAppResponse struct {
	AppRevisionId string                 `json:"app_revision_id"`
	CLIAction     porterv1.EnumCLIAction `json:"cli_action"`
}

// ServeHTTP translates the request into a ApplyPorterApp request, forwards to the cluster control plane, and returns the response
func (c *ApplyPorterAppHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	ctx, span := telemetry.NewSpan(r.Context(), "serve-apply-porter-app")
	defer span.End()

	project, _ := ctx.Value(types.ProjectScope).(*models.Project)
	cluster, _ := ctx.Value(types.ClusterScope).(*models.Cluster)

	telemetry.WithAttributes(span,
		telemetry.AttributeKV{Key: "project-id", Value: project.ID},
		telemetry.AttributeKV{Key: "cluster-id", Value: cluster.ID},
	)

	if !project.GetFeatureFlag(models.ValidateApplyV2, c.Config().LaunchDarklyClient) {
		err := telemetry.Error(ctx, span, nil, "project does not have validate apply v2 enabled")
		c.HandleAPIError(w, r, apierrors.NewErrForbidden(err))
		return
	}

	request := &ApplyPorterAppRequest{}
	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
	}

	var appRevisionID string
	var appProto *porterv1.PorterApp
	var deploymentTargetID string

	if request.AppRevisionID != "" {
		appRevisionID = request.AppRevisionID
		telemetry.WithAttributes(span, telemetry.AttributeKV{Key: "app-revision-id", Value: request.AppRevisionID})
	} else {
		if request.Base64AppProto == "" {
			err := telemetry.Error(ctx, span, nil, "b64 yaml is empty")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
			return
		}

		decoded, err := base64.StdEncoding.DecodeString(request.Base64AppProto)
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error decoding base yaml")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
			return
		}

		appProto = &porterv1.PorterApp{}
		err = helpers.UnmarshalContractObject(decoded, appProto)
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error unmarshalling app proto")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
			return
		}

		app, err := v2.AppFromProto(appProto)
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error converting app proto to app")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
			return
		}

		if request.DeploymentTargetId == "" {
			err := telemetry.Error(ctx, span, err, "deployment target id is empty")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
			return
		}
		deploymentTargetID = request.DeploymentTargetId

		telemetry.WithAttributes(span,
			telemetry.AttributeKV{Key: "app-name", Value: appProto.Name},
			telemetry.AttributeKV{Key: "deployment-target-id", Value: request.DeploymentTargetId},
		)

		deploymentTargetDetails, err := deployment_target.DeploymentTargetDetails(ctx, deployment_target.DeploymentTargetDetailsInput{
			ProjectID:          int64(project.ID),
			ClusterID:          int64(cluster.ID),
			DeploymentTargetID: deploymentTargetID,
			CCPClient:          c.Config().ClusterControlPlaneClient,
		})
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error getting deployment target details")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
			return
		}

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

		subdomainCreateInput := porter_app.CreatePorterSubdomainInput{
			AppName:             app.Name,
			RootDomain:          c.Config().ServerConf.AppRootDomain,
			DNSClient:           c.Config().DNSClient,
			DNSRecordRepository: c.Repo().DNSRecord(),
			KubernetesAgent:     agent,
		}

		appWithDomains, err := addPorterSubdomainsIfNecessary(ctx, app, deploymentTargetDetails, subdomainCreateInput)
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error adding porter subdomains")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusBadRequest))
			return
		}

		appProto, _, err = v2.ProtoFromApp(ctx, appWithDomains)
		if err != nil {
			err := telemetry.Error(ctx, span, err, "error converting app to proto")
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
			return
		}
	}

	applyReq := connect.NewRequest(&porterv1.ApplyPorterAppRequest{
		ProjectId:           int64(project.ID),
		DeploymentTargetId:  deploymentTargetID,
		App:                 appProto,
		PorterAppRevisionId: appRevisionID,
		ForceBuild:          request.ForceBuild,
	})
	ccpResp, err := c.Config().ClusterControlPlaneClient.ApplyPorterApp(ctx, applyReq)
	if err != nil {
		err := telemetry.Error(ctx, span, err, "error calling ccp apply porter app")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	if ccpResp == nil {
		err := telemetry.Error(ctx, span, err, "ccp resp is nil")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}
	if ccpResp.Msg == nil {
		err := telemetry.Error(ctx, span, err, "ccp resp msg is nil")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	if ccpResp.Msg.PorterAppRevisionId == "" {
		err := telemetry.Error(ctx, span, err, "ccp resp app revision id is nil")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	telemetry.WithAttributes(span, telemetry.AttributeKV{Key: "resp-app-revision-id", Value: ccpResp.Msg.PorterAppRevisionId})

	if ccpResp.Msg.CliAction == porterv1.EnumCLIAction_ENUM_CLI_ACTION_UNSPECIFIED {
		err := telemetry.Error(ctx, span, err, "ccp resp cli action is nil")
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, http.StatusInternalServerError))
		return
	}

	telemetry.WithAttributes(span, telemetry.AttributeKV{Key: "cli-action", Value: ccpResp.Msg.CliAction.String()})

	response := &ApplyPorterAppResponse{
		AppRevisionId: ccpResp.Msg.PorterAppRevisionId,
		CLIAction:     ccpResp.Msg.CliAction,
	}

	c.WriteResult(w, r, response)
}

// addPorterSubdomainsIfNecessary adds porter subdomains to the app proto if a web service is changed to private and has no domains
func addPorterSubdomainsIfNecessary(ctx context.Context, app v2.PorterApp, deploymentTarget deployment_target.DeploymentTarget, createSubdomainInput porter_app.CreatePorterSubdomainInput) (v2.PorterApp, error) {
	ctx, span := telemetry.NewSpan(ctx, "add-porter-subdomains-if-necessary")
	defer span.End()

	services := make([]v2.Service, 0)

	for _, service := range app.Services {
		if service.Type == v2.ServiceType_Web {
			if service.Private != nil && !*service.Private && service.Domains != nil && len(service.Domains) == 0 {
				if deploymentTarget.Namespace != DeploymentTargetSelector_Default {
					createSubdomainInput.AppName = fmt.Sprintf("%s-%s", createSubdomainInput.AppName, deploymentTarget.ID[:6])
				}

				subdomain, err := porter_app.CreatePorterSubdomain(ctx, createSubdomainInput)
				if err != nil {
					return app, fmt.Errorf("error creating subdomain: %w", err)
				}

				if subdomain == "" {
					return app, errors.New("response subdomain is empty")
				}

				service.Domains = []v2.Domains{
					{Name: subdomain},
				}
			}
		}

		services = append(services, service)
	}

	app.Services = services

	return app, nil
}