// Copyright 2026 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package stack

import (
	stdctx "context"
	"fmt"

	"gitea.dev/tea/cmd/flags"
	"gitea.dev/tea/modules/context"
	"gitea.dev/tea/modules/task"
	"gitea.dev/tea/modules/utils"

	"github.com/urfave/cli/v3"
)

// CmdStackMerge represents a sub command to merge a pull request stack in order
var CmdStackMerge = cli.Command{
	Name:        "merge",
	Aliases:     []string{"m"},
	Usage:       "Merge a pull request stack in order",
	Description: "Merge every pull request of a stack in order, bottom first",
	ArgsUsage:   "<stack id>",
	Action:      RunStackMerge,
	Flags: append([]cli.Flag{
		&cli.StringFlag{
			Name:    "style",
			Aliases: []string{"s"},
			Usage:   "Kind of merge to perform: merge, rebase, squash, rebase-merge",
			Value:   "merge",
		},
		&cli.BoolFlag{
			Name:  "wait-for-ci",
			Usage: "Schedule the merge to run once required checks pass, instead of merging immediately",
		},
	}, flags.AllDefaultFlags...),
}

// RunStackMerge merges every pull request of a stack in order
func RunStackMerge(requestCtx stdctx.Context, cmd *cli.Command) error {
	if cmd.Args().Len() != 1 {
		return fmt.Errorf("stack id is required")
	}
	id, err := utils.ArgToIndex(cmd.Args().First())
	if err != nil {
		return err
	}

	ctx, err := context.InitCommand(cmd)
	if err != nil {
		return err
	}
	if err := ctx.Ensure(context.CtxRequirement{RemoteRepo: true}); err != nil {
		return err
	}

	result, queued, err := task.MergePullStack(requestCtx, ctx.Login, ctx.Owner, ctx.Repo, id,
		cmd.String("style"), cmd.Bool("wait-for-ci"))
	if queued {
		fmt.Fprintf(ctx.Writer, "merge for stack #%d scheduled\n", id)
		return nil
	}
	if err != nil {
		if result != nil {
			return fmt.Errorf("merged %d pull request(s) before failing: %w", result.Merged, err)
		}
		return err
	}

	fmt.Fprintf(ctx.Writer, "merged %d pull request(s) of stack #%d\n", result.Merged, id)
	return nil
}