package delete

import (
	"fmt"
	"strconv"

	"github.com/MakeNowJust/heredoc"
	"github.com/cli/cli/v2/pkg/cmd/project/shared/client"
	"github.com/cli/cli/v2/pkg/cmd/project/shared/format"
	"github.com/cli/cli/v2/pkg/cmd/project/shared/queries"
	"github.com/cli/cli/v2/pkg/cmdutil"
	"github.com/cli/cli/v2/pkg/iostreams"
	"github.com/shurcooL/githubv4"
	"github.com/spf13/cobra"
)

type deleteOpts struct {
	owner     string
	number    int32
	projectID string
	format    string
}

type deleteConfig struct {
	client *queries.Client
	opts   deleteOpts
	io     *iostreams.IOStreams
}

type deleteProjectMutation struct {
	DeleteProject struct {
		Project queries.Project `graphql:"projectV2"`
	} `graphql:"deleteProjectV2(input:$input)"`
}

func NewCmdDelete(f *cmdutil.Factory, runF func(config deleteConfig) error) *cobra.Command {
	opts := deleteOpts{}
	deleteCmd := &cobra.Command{
		Short: "Delete a project",
		Use:   "delete [<number>]",
		Example: heredoc.Doc(`
			# delete the current user's project "1"
			gh project delete 1 --owner "@me"
		`),
		Args: cobra.MaximumNArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			client, err := client.New(f)
			if err != nil {
				return err
			}

			if len(args) == 1 {
				num, err := strconv.ParseInt(args[0], 10, 32)
				if err != nil {
					return cmdutil.FlagErrorf("invalid number: %v", args[0])
				}
				opts.number = int32(num)
			}

			config := deleteConfig{
				client: client,
				opts:   opts,
				io:     f.IOStreams,
			}

			// allow testing of the command without actually running it
			if runF != nil {
				return runF(config)
			}
			return runDelete(config)
		},
	}

	deleteCmd.Flags().StringVar(&opts.owner, "owner", "", "Login of the owner. Use \"@me\" for the current user.")
	cmdutil.StringEnumFlag(deleteCmd, &opts.format, "format", "", "", []string{"json"}, "Output format")

	return deleteCmd
}

func runDelete(config deleteConfig) error {
	canPrompt := config.io.CanPrompt()
	owner, err := config.client.NewOwner(canPrompt, config.opts.owner)
	if err != nil {
		return err
	}

	project, err := config.client.NewProject(canPrompt, owner, config.opts.number, false)
	if err != nil {
		return err
	}
	config.opts.projectID = project.ID

	query, variables := deleteItemArgs(config)
	err = config.client.Mutate("DeleteProject", query, variables)
	if err != nil {
		return err
	}

	if config.opts.format == "json" {
		return printJSON(config, *project)
	}

	return printResults(config, query.DeleteProject.Project)

}

func deleteItemArgs(config deleteConfig) (*deleteProjectMutation, map[string]interface{}) {
	return &deleteProjectMutation{}, map[string]interface{}{
		"input": githubv4.DeleteProjectV2Input{
			ProjectID: githubv4.ID(config.opts.projectID),
		},
		"firstItems":  githubv4.Int(0),
		"afterItems":  (*githubv4.String)(nil),
		"firstFields": githubv4.Int(0),
		"afterFields": (*githubv4.String)(nil),
	}
}

func printResults(config deleteConfig, project queries.Project) error {
	if !config.io.IsStdoutTTY() {
		return nil
	}

	_, err := fmt.Fprintf(config.io.Out, "Deleted project %d\n", project.Number)
	return err
}

func printJSON(config deleteConfig, project queries.Project) error {
	b, err := format.JSONProject(project)
	if err != nil {
		return err
	}

	_, err = config.io.Out.Write(b)
	return err
}
