/*
Copyright © 2026 Thomas von Dein

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package cmd

import (
	"context"
	"errors"
	"slices"

	"codeberg.org/scip/esctl/pkg/cfg"
	"codeberg.org/scip/esctl/pkg/es"

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

func IlmForecast(conf *cfg.Config) *cli.Command {
	return &cli.Command{
		Name:  "forecast",
		Usage: "calculate index phase movements",

		Commands: []*cli.Command{
			IlmForecastList(conf),
			IlmForecastShow(conf),
		},
	}
}

const IlmForeCastListReference = `<duration> must be a string which consists one or more of these elements:
d - days
h - hours
m - minutes
s - seconds

Examples:

58d12h  - 58 days and 12 hours
122h30m - 122 hours and 30 minutes

Specs may be mixed:

8h12d   - 12 days and 8 hours`

func IlmForecastList(conf *cfg.Config) *cli.Command {
	return &cli.Command{
		Name:               "list",
		Aliases:            []string{"ls"},
		Usage:              "list index rollover config",
		UsageText:          "list [options] [<filter>]",
		CustomHelpTemplate: addReference(IlmForeCastListReference),

		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:        "from-phase",
				Usage:       "which ilm phase to forecast from",
				Destination: &conf.Ilm.FromPhase,
				Aliases:     []string{"f"},
			},
			&cli.StringFlag{
				Name:        "within",
				Usage:       "<duration> withing which to forecast",
				Destination: &conf.Ilm.Within,
				Aliases:     []string{"w"},
			},
			&cli.StringFlag{
				Name:        "min-age",
				Usage:       "show only indices older than <duration>",
				Destination: &conf.Ilm.MinAge,
				Aliases:     []string{"m"},
			},
			&cli.BoolFlag{
				Name:        "verbose",
				Usage:       "show ilm policy as well",
				Destination: &conf.Verbose,
				Aliases:     []string{"v"},
			},
			&cli.BoolFlag{
				Name:        "hidden",
				Usage:       "include hidden indicies",
				Destination: &conf.Hidden,
				Aliases:     []string{"H"},
			},
		},

		Action: func(ctx context.Context, cmd *cli.Command) error {
			valid := []string{"hot", "warm", "cold", "frozen"}
			if !slices.Contains(valid, conf.Ilm.FromPhase) {
				return errors.New("invalid from phase, allowed: hot, warm, cold, frozen")
			}

			return es.IlmForecastList(conf, cmd.Args().Get(0))
		},
	}
}

func IlmForecastShow(conf *cfg.Config) *cli.Command {
	return &cli.Command{
		Name:    "show",
		Aliases: []string{"sh"},
		Usage:   "show rollover forecast over all indices",

		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:        "from-phase",
				Usage:       "which ilm phase to forecast from",
				Destination: &conf.Ilm.FromPhase,
				Aliases:     []string{"f"},
			},
			&cli.StringFlag{
				Name:        "within",
				Usage:       "duration withing which to forecast",
				Destination: &conf.Ilm.Within,
				Aliases:     []string{"w"},
			},
		},

		Action: func(ctx context.Context, cmd *cli.Command) error {
			valid := []string{"hot", "warm", "cold", "frozen"}
			if !slices.Contains(valid, conf.Ilm.FromPhase) {
				return errors.New("invalid from phase, allowed: hot, warm, cold, frozen")
			}

			return es.IlmForecastShow(conf)
		},
	}
}