package environment

import (
	"errors"
	"fmt"
	"net/http"
	"strconv"

	"github.com/google/go-github/v41/github"
	"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/commonutils"
	"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"
	"github.com/porter-dev/porter/internal/models"
)

var ErrNoWorkflowRuns = errors.New("no previous workflow runs found")

type TriggerDeploymentWorkflowHandler struct {
	handlers.PorterHandlerReadWriter
}

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

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

	deplID, reqErr := requestutils.GetURLParamUint(r, "deployment_id")

	if reqErr != nil {
		c.HandleAPIError(w, r, reqErr)
		return
	}

	depl, err := c.Repo().Environment().ReadDeploymentByID(project.ID, cluster.ID, deplID)
	if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}

	if depl.Status == types.DeploymentStatusInactive {
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(
			fmt.Errorf("trying to trigger workflow run for inactive deployment"), http.StatusConflict,
		))
		return
	}

	env, err := c.Repo().Environment().ReadEnvironmentByID(project.ID, cluster.ID, depl.EnvironmentID)
	if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}

	client, err := getGithubClientFromEnvironment(c.Config(), env)
	if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}

	if !depl.IsBranchDeploy() {
		// add a check for the PR to be open before creating a comment
		prClosed, err := isGithubPRClosed(client, depl.RepoOwner, depl.RepoName, int(depl.PullRequestID))
		if err != nil {
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(
				fmt.Errorf("error fetching details of github PR for deployment ID: %d. Error: %w",
					depl.ID, err), http.StatusConflict,
			))
			return
		}

		if prClosed {
			c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(fmt.Errorf("Github PR has been closed"),
				http.StatusConflict))
			return
		}
	}

	latestWorkflowRun, err := commonutils.GetLatestWorkflowRun(client, env.GitRepoOwner, env.GitRepoName,
		fmt.Sprintf("porter_%s_env.yml", env.Name), depl.PRBranchFrom)

	if err != nil && errors.Is(err, ErrNoWorkflowRuns) {
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(err, 400))
		return
	} else if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}

	if latestWorkflowRun.GetStatus() == "in_progress" || latestWorkflowRun.GetStatus() == "queued" {
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(fmt.Errorf("workflow already in progress"), 409))
		return
	}

	prNumber := depl.PullRequestID

	if depl.IsBranchDeploy() {
		prNumber = depl.ID
	}

	ghResp, err := client.Actions.CreateWorkflowDispatchEventByFileName(
		r.Context(), env.GitRepoOwner, env.GitRepoName, fmt.Sprintf("porter_%s_env.yml", env.Name),
		github.CreateWorkflowDispatchEventRequest{
			Ref: depl.PRBranchFrom,
			Inputs: map[string]interface{}{
				"pr_number":      strconv.FormatUint(uint64(prNumber), 10),
				"pr_title":       depl.PRName,
				"pr_branch_from": depl.PRBranchFrom,
				"pr_branch_into": depl.PRBranchInto,
			},
		},
	)

	if ghResp != nil && ghResp.StatusCode == 404 {
		c.HandleAPIError(w, r, apierrors.NewErrPassThroughToClient(fmt.Errorf("workflow file not found"), 404))
		return
	}

	if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}

	// set the status to updating manually here for the frontend to case on
	depl.Status = types.DeploymentStatusUpdating

	_, err = c.Repo().Environment().UpdateDeployment(depl)

	if err != nil {
		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
		return
	}
}