package command

import (
	"fmt"
	"time"

	"github.com/google/uuid"
	"go-mod.ewintr.nl/planner/item"
	"go-mod.ewintr.nl/planner/plan/storage"
)

const (
	FlagOn  = "on"
	FlagAt  = "at"
	FlagFor = "for"
)

type AddCmd struct {
	localIDRepo storage.LocalID
	eventRepo   storage.Event
	syncRepo    storage.Sync
}

func NewAddCmd(localRepo storage.LocalID, eventRepo storage.Event, syncRepo storage.Sync) Command {
	return &AddCmd{
		localIDRepo: localRepo,
		eventRepo:   eventRepo,
		syncRepo:    syncRepo,
	}
}

func (add *AddCmd) Parse(args []string) (*ArgSet, error) {
	if len(args) == 0 || args[0] != "add" {
		return nil, ErrWrongCommand
	}
	as, err := ParseArgs(args[1:])
	if err != nil {
		return nil, err
	}

	if as.Main == "" {
		return nil, fmt.Errorf("%w: title is required", ErrInvalidArg)
	}
	if !as.HasFlag(FlagOn) {
		return nil, fmt.Errorf("%w: date is required", ErrInvalidArg)
	}
	if !as.HasFlag(FlagAt) && as.HasFlag(FlagFor) {
		return nil, fmt.Errorf("%w: can not have duration without start time", ErrInvalidArg)
	}
	if !as.HasFlag(FlagAt) && !as.HasFlag(FlagFor) {
		as.SetFlag(FlagFor, "24h")
	}

	return as, nil
}

func (add *AddCmd) Do(as *ArgSet) error {
	startFormat := "2006-01-02"
	startStr := as.Flag(FlagOn)
	if as.HasFlag(FlagAt) {
		startFormat = fmt.Sprintf("%s 15:04", startFormat)
		startStr = fmt.Sprintf("%s %s", startStr, as.Flag(FlagAt))
	}
	start, err := time.Parse(startFormat, startStr)
	if err != nil {
		return fmt.Errorf("%w: could not parse start time and date: %v", ErrInvalidArg, err)
	}

	e := item.Event{
		ID: uuid.New().String(),
		EventBody: item.EventBody{
			Title: as.Main,
			Start: start,
		},
	}

	if as.HasFlag(FlagFor) {
		fr, err := time.ParseDuration(as.Flag(FlagFor))
		if err != nil {
			return fmt.Errorf("%w: could not parse duration: %s", ErrInvalidArg, err)
		}
		e.Duration = fr
	}
	if err := add.eventRepo.Store(e); err != nil {
		return fmt.Errorf("could not store event: %v", err)
	}

	localID, err := add.localIDRepo.Next()
	if err != nil {
		return fmt.Errorf("could not create next local id: %v", err)
	}
	if err := add.localIDRepo.Store(e.ID, localID); err != nil {
		return fmt.Errorf("could not store local id: %v", err)
	}

	it, err := e.Item()
	if err != nil {
		return fmt.Errorf("could not convert event to sync item: %v", err)
	}
	if err := add.syncRepo.Store(it); err != nil {
		return fmt.Errorf("could not store sync item: %v", err)
	}

	return nil
}