package bulldozesynclabel

import (
	"fmt"
	"strconv"
	"strings"

	"github.com/google/go-github/v47/github"

	"edge-infra.dev/pkg/f8n/devinfra/jack/constants"
	"edge-infra.dev/pkg/f8n/devinfra/jack/plugin"
)

func init() {
	plugin.RegisterStatusEventHandler(constants.PluginApprovedLabel, handleStatusEvent)
}

func handleStatusEvent(hp plugin.HandlerParams, se github.StatusEvent) {
	hp.Log.WithName(constants.PluginApprovedLabel)

	// check is the status event has a context that matches policybot
	if se.GetContext() != "mergeable: master" {
		return
	}
	hp.Log.Info("Running approved_label")
	hp.Log.Info("found a policybot status event")

	// get the pr number from the target url
	// maybe not the best way but simplest solution first
	// ex: "target_url": "https://policy-bot.edge-infra.dev/details/ncrvoyix-swt-retail/edge-infra/2392"
	prArr := strings.Split(se.GetTargetURL(), "/")

	// get the last index which should be the pr num
	prStr := prArr[len(prArr)-1]

	// convert it from string to int
	prNum, err := strconv.Atoi(prStr)
	if err != nil {
		hp.Log.Error(err, "Failed to get PR number")
		return
	}

	// get the pr
	pr, _, err := hp.Client.PullRequests().Get(hp.Ctx, hp.Org, hp.Repo, prNum)
	if err != nil {
		hp.Log.Error(err, "Failed to retrieve PR")
		return
	}

	// check if the issue already has the labels
	hasOK := hasApproved(pr.Labels)
	hasDoNotMerge := hasDoNotMerge(pr.Labels)

	// We don't want to sync drafts
	if pr.GetDraft() && hasOK {
		hp.Log.Info(fmt.Sprintf("PR #%d is a draft. Attempting to remove %s", prNum, constants.Approved))
		removeSyncLabel(hp, prNum)
		return
	}

	// Don't sync PR's with do-not-merge label
	if hasDoNotMerge && hasOK {
		hp.Log.Info(fmt.Sprintf("Cannot sync while %s is present. Attempting to remove %s", constants.DoNotMerge, constants.Approved))
		removeSyncLabel(hp, prNum)
		return
	}

	// check the state and call the appropriate func
	state := se.GetState()
	switch {
	case state == "success" && !hasOK:
		addLabel(hp, prNum)
	case (state == "pending" || state == "failure") && hasOK:
		removeSyncLabel(hp, prNum)
	}
}

func hasApproved(labels []*github.Label) bool {
	for _, label := range labels {
		if label.GetName() == constants.Approved {
			return true
		}
	}
	return false
}

func hasDoNotMerge(labels []*github.Label) bool {
	for _, label := range labels {
		if label.GetName() == constants.DoNotMerge {
			return true
		}
	}
	return false
}

func addLabel(hp plugin.HandlerParams, num int) {
	hp.Log.Info(fmt.Sprintf("adding %s", constants.Approved))

	labels := []string{constants.Approved}
	_, _, err := hp.Client.Issues().AddLabelsToIssue(hp.Ctx, hp.Org, hp.Repo, num, labels)
	if err != nil {
		hp.Log.Error(err, fmt.Sprintf("Failed to add %s", constants.Approved))
	}
}

func removeSyncLabel(hp plugin.HandlerParams, num int) {
	hp.Log.Info(fmt.Sprintf("removing %s", constants.Approved))

	_, err := hp.Client.Issues().RemoveLabelForIssue(hp.Ctx, hp.Org, hp.Repo, num, constants.Approved)
	if err != nil {
		hp.Log.Error(err, fmt.Sprintf("Failed to remove %s", constants.Approved))
	}
}