// 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/print"
	pullstack "gitea.dev/tea/modules/stack"
	"gitea.dev/tea/modules/task"
	"gitea.dev/tea/modules/utils"

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

// CmdStackPush represents a sub command to link a pull request onto a stack
var CmdStackPush = cli.Command{
	Name:        "push",
	Usage:       "Link a pull request onto a stack",
	Description: "Link a child pull request onto its parent, creating a new stack or extending an existing one with --stack",
	ArgsUsage:   "<parent index> <child index>",
	Action:      RunStackPush,
	Flags: append([]cli.Flag{
		&cli.Int64Flag{
			Name:  "stack",
			Usage: "id of an existing stack to append the pull requests to, instead of creating a new stack",
		},
	}, flags.AllDefaultFlags...),
}

// RunStackPush links a parent and a child pull request into a stack
func RunStackPush(requestCtx stdctx.Context, cmd *cli.Command) error {
	if cmd.Args().Len() != 2 {
		return fmt.Errorf("parent index and child index are required")
	}
	parentIndex, err := utils.ArgToIndex(cmd.Args().Get(0))
	if err != nil {
		return err
	}
	childIndex, err := utils.ArgToIndex(cmd.Args().Get(1))
	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
	}

	var s *pullstack.Stack
	if stackID := cmd.Int64("stack"); stackID != 0 {
		s, err = task.AddPullStackEntry(requestCtx, ctx.Login, ctx.Owner, ctx.Repo, stackID, parentIndex, childIndex)
	} else {
		s, err = task.CreatePullStack(requestCtx, ctx.Login, ctx.Owner, ctx.Repo, parentIndex, childIndex)
	}
	if err != nil {
		return err
	}

	print.PullStackDetail(s)
	return nil
}