package cmd

import (
	"fmt"
	"io"

	wisski_distillery "github.com/FAU-CDI/wisski-distillery"
	"github.com/FAU-CDI/wisski-distillery/internal/component/instances"
	"github.com/FAU-CDI/wisski-distillery/internal/core"
	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
	"github.com/FAU-CDI/wisski-distillery/pkg/slicesx"
	"github.com/tkw1536/goprogram/exit"
	"github.com/tkw1536/goprogram/status"
	"github.com/tkw1536/goprogram/stream"
)

// BlindUpdate is the 'blind_update' command
var BlindUpdate wisski_distillery.Command = blindUpdate{}

type blindUpdate struct {
	Parallel    int  `short:"p" long:"parallel" description:"run on (at most) this many instances concurrently. 0 for no limit." default:"1"`
	Force       bool `short:"f" long:"force" description:"force running blind-update even if AutoBlindUpdate is set to false"`
	Positionals struct {
		Slug []string `positional-arg-name:"SLUG" required:"0" description:"slug of instance(s) to run blind-update in"`
	} `positional-args:"true"`
}

func (blindUpdate) Description() wisski_distillery.Description {
	return wisski_distillery.Description{
		Requirements: core.Requirements{
			NeedsDistillery: true,
		},
		Command:     "blind_update",
		Description: "Runs the blind update in the provided instances",
	}
}

var errBlindUpdateFailed = exit.Error{
	Message:  "Failed to run blind update script for instance %q: exited with code %s",
	ExitCode: exit.ExitGeneric,
}

func (bu blindUpdate) Run(context wisski_distillery.Context) error {
	wissKIs, err := context.Environment.Instances().Load(bu.Positionals.Slug...)
	if err != nil {
		return err
	}
	if !bu.Force {
		wissKIs = slicesx.Filter(wissKIs, func(instance instances.WissKI) bool {
			return bool(instance.AutoBlindUpdateEnabled)
		})
	}

	if bu.Parallel == 1 {
		return bu.runSequential(wissKIs, context)
	}

	return bu.runParallel(wissKIs, context)
}

func (bu blindUpdate) runParallel(wissKIs []instances.WissKI, context wisski_distillery.Context) error {
	return status.RunErrorGroup(context.Stdout, status.Group[instances.WissKI, error]{
		PrefixString: func(item instances.WissKI, index int) string {
			return fmt.Sprintf("[instance %q]: ", item.Slug)
		},
		PrefixAlign: true,

		Handler: func(instance instances.WissKI, index int, writer io.Writer) error {
			io := stream.NewIOStream(writer, writer, nil, 0)

			code, err := instance.Shell(io, "/runtime/blind_update.sh")
			if err != nil {
				return errBlindUpdateFailed.WithMessageF(instance.Slug, environment.ExecCommandError)
			}
			if code != 0 {
				return errBlindUpdateFailed.WithMessageF(instance.Slug, code)
			}
			return nil
		},
		HandlerLimit: bu.Parallel,
	}, wissKIs)
}

func (bu blindUpdate) runSequential(wissKIs []instances.WissKI, context wisski_distillery.Context) error {
	for _, instance := range wissKIs {
		context.EPrintf("Updating instance %s\n", instance.Slug)

		code, err := instance.Shell(context.IOStream, "/runtime/blind_update.sh")
		if err != nil {
			return errBlindUpdateFailed.WithMessageF(instance.Slug, environment.ExecCommandError)
		}
		if code != 0 {
			return errBlindUpdateFailed.WithMessageF(instance.Slug, code)
		}
	}
	return nil
}