package shared

import (
	"context"
	"net/http"

	"github.com/cli/cli/v2/api"
	"github.com/cli/cli/v2/internal/ghinstance"
	"github.com/cli/cli/v2/internal/ghrepo"
	graphql "github.com/cli/shurcooL-graphql"
	"github.com/shurcooL/githubv4"
)

func UpdateIssue(httpClient *http.Client, repo ghrepo.Interface, id string, isPR bool, options Editable) error {
	title := ghString(options.TitleValue())
	body := ghString(options.BodyValue())

	apiClient := api.NewClientFromHTTP(httpClient)
	assigneeIds, err := options.AssigneeIds(apiClient, repo)
	if err != nil {
		return err
	}

	labelIds, err := options.LabelIds()
	if err != nil {
		return err
	}

	projectIds, err := options.ProjectIds()
	if err != nil {
		return err
	}

	milestoneId, err := options.MilestoneId()
	if err != nil {
		return err
	}

	if isPR {
		params := githubv4.UpdatePullRequestInput{
			PullRequestID: id,
			Title:         title,
			Body:          body,
			AssigneeIDs:   ghIds(assigneeIds),
			LabelIDs:      ghIds(labelIds),
			ProjectIDs:    ghIds(projectIds),
			MilestoneID:   ghId(milestoneId),
		}
		if options.Base.Edited {
			params.BaseRefName = ghString(&options.Base.Value)
		}
		return updatePullRequest(httpClient, repo, params)
	}

	return updateIssue(httpClient, repo, githubv4.UpdateIssueInput{
		ID:          id,
		Title:       title,
		Body:        body,
		AssigneeIDs: ghIds(assigneeIds),
		LabelIDs:    ghIds(labelIds),
		ProjectIDs:  ghIds(projectIds),
		MilestoneID: ghId(milestoneId),
	})
}

func updateIssue(httpClient *http.Client, repo ghrepo.Interface, params githubv4.UpdateIssueInput) error {
	var mutation struct {
		UpdateIssue struct {
			Issue struct {
				ID string
			}
		} `graphql:"updateIssue(input: $input)"`
	}
	variables := map[string]interface{}{"input": params}
	gql := graphql.NewClient(ghinstance.GraphQLEndpoint(repo.RepoHost()), httpClient)
	return gql.MutateNamed(context.Background(), "IssueUpdate", &mutation, variables)
}

func updatePullRequest(httpClient *http.Client, repo ghrepo.Interface, params githubv4.UpdatePullRequestInput) error {
	var mutation struct {
		UpdatePullRequest struct {
			PullRequest struct {
				ID string
			}
		} `graphql:"updatePullRequest(input: $input)"`
	}
	variables := map[string]interface{}{"input": params}
	gql := graphql.NewClient(ghinstance.GraphQLEndpoint(repo.RepoHost()), httpClient)
	err := gql.MutateNamed(context.Background(), "PullRequestUpdate", &mutation, variables)
	return err
}

func ghIds(s *[]string) *[]githubv4.ID {
	if s == nil {
		return nil
	}
	ids := make([]githubv4.ID, len(*s))
	for i, v := range *s {
		ids[i] = v
	}
	return &ids
}

func ghId(s *string) *githubv4.ID {
	if s == nil {
		return nil
	}
	if *s == "" {
		r := githubv4.ID(nil)
		return &r
	}
	r := githubv4.ID(*s)
	return &r
}

func ghString(s *string) *githubv4.String {
	if s == nil {
		return nil
	}
	r := githubv4.String(*s)
	return &r
}