package triageissue

import (
	"fmt"
	"net/http"
	"strings"

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

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

func init() {
	plugin.RegisterIssueCommentHandler(constants.PluginPRIssue, handlePRComment)
	plugin.RegisterPullRequestHandler(constants.PluginPRIssue, handlePR)
}

func handlePRComment(hp plugin.HandlerParams, ice github.IssueCommentEvent) {
	hp.Log.WithName(constants.PluginPRIssue)

	if ice.GetAction() != "created" {
		return
	}
	if !ice.GetIssue().IsPullRequest() {
		return
	}

	prBody := ice.Issue.GetBody()
	prComment := ice.Comment.GetBody()

	// if the new comment doesnt have the relevant command exit
	if !strings.Contains(prComment, "/link") {
		return
	}

	issueCommand := guestservices.GetCommandsFromPRBody(prComment, "link")

	//LinkNum needed to isolate the relevant link in the PR body that will be changed
	//LastIndex is the where the linkNum is located
	//CommentSplit parses the comment body to separate the link
	//CommentLink stores the link from commentSplit
	linkNum, _ := guestservices.ParsePRIssueLinkBody(prBody)
	lastIndex := strings.LastIndex(prBody, linkNum)

	commentSplit := strings.SplitN(prComment, "#", -1)
	if len(commentSplit) < 2 {
		hp.Log.Info("comment doesnt have enough info to link an issue ignoring")
		return
	}
	commentLink := commentSplit[1]

	// if there is an issue command to remove issue, add label
	if len(issueCommand.RemoveIssue) > 0 {
		// Editing the PR body to include ISSUE_NUMBER_HERE at the end of the link
		prBody = prBody[:lastIndex] + strings.Replace(prBody[lastIndex:], linkNum, "ISSUE_NUMBER_HERE", 1)
		edited := github.IssueRequest{Body: &prBody}
		_, _, err := hp.Client.Issues().Edit(hp.Ctx, hp.Org, hp.Repo, ice.Issue.GetNumber(), &edited)
		if err != nil {
			return
		}

		// Adding the needs-issue label
		hp.Log.Info(fmt.Sprintf("attempting to add %s", constants.TriageIssueLabel))
		newLabels := []string{constants.TriageIssueLabel}
		_, _, err = hp.Client.Issues().AddLabelsToIssue(hp.Ctx, hp.Org, hp.Repo, ice.Issue.GetNumber(), newLabels)
		if err != nil {
			return
		}
		labelApplied = true
		return
	}

	// if there is an issue command to add issue, remove label
	if len(issueCommand.AddIssue) > 0 {
		// Verifying that the new link works
		_, err := http.Get(ghURL + constants.Address + commentLink)
		if err != nil {
			return
		}

		// Editing the PR body to include the new link
		prBody = prBody[:lastIndex] + strings.Replace(prBody[lastIndex:], linkNum, commentLink, 1)
		edited := github.IssueRequest{Body: &prBody}
		_, _, err = hp.Client.Issues().Edit(hp.Ctx, hp.Org, hp.Repo, ice.Issue.GetNumber(), &edited)
		if err != nil {
			return
		}

		// Removing the needs-issue label
		hp.Log.Info(fmt.Sprintf("attempting to remove %s", constants.TriageIssueLabel))
		_, err = hp.Client.Issues().RemoveLabelForIssue(hp.Ctx, hp.Org, hp.Repo, ice.Issue.GetNumber(), constants.TriageIssueLabel)
		if err != nil {
			return
		}
		labelApplied = false
		return
	}
}

// handlePR checks the log for four specific responses.
// Anytime those responses appear, the appropriate function will be called.
func handlePR(hp plugin.HandlerParams, pre github.PullRequestEvent) {
	hp.Log.WithName(constants.PluginPRIssue)

	action := pre.GetAction()
	switch action {
	case "opened":
		if err := checkForIssueInPR(hp, pre); err != nil {
			hp.Log.Error(err, "Issue: Failed to check for issue in PR")
			return
		}
	case "labeled":
		if err := addLabel(hp, pre); err != nil {
			hp.Log.Error(err, "Issue: Failed to add triage-issue label")
			return
		}
	case "unlabeled":
		if err := removeLabel(hp, pre); err != nil {
			hp.Log.Error(err, "Issue: Failed to remove triage-issue label")
			return
		}
	case "edited":
		if err := editedPRBody(hp, pre); err != nil {
			hp.Log.Error(err, "Issue: Failed to handle edited PR body")
			return
		}
	}
}