package domain

import (
	"io"
	"time"
	"strconv"
)


type BogFileService struct {
	user_agent_repo UserAgentRepository
	file_data_repo FileDataRepository
	default_allowance_bytes int64
	default_allowance_duration time.Duration
}

func NewBogFileService(
	user_agent_repo UserAgentRepository,
	file_data_repo FileDataRepository,
	da_bytes int64,
	da_duration time.Duration,
) BogFileService {
	return BogFileService {user_agent_repo, file_data_repo, da_bytes, da_duration}
}

func (b BogFileService) getOrCreateUA(useragent_in string) *UserAgent{
	ua, err := b.user_agent_repo.GetByName(useragent_in)

	if err == ErrNotExists {
		new_ua := UserAgent {
			0, useragent_in, time.Now(), b.default_allowance_duration, FileSizeQuota { b.default_allowance_bytes, 0 },
		}
		created_ua, err := b.user_agent_repo.Create(new_ua)

		if err != nil {
			panic(err)
		}

		return created_ua
	}

	if err != nil {
		panic(err)
	}

	return ua
}

func (b BogFileService) SaveFile(ref FileReference, src io.Reader, size int64) error {
	user_agent := b.getOrCreateUA(ref.UserAgent)

	if !user_agent.FileQuota.Allows(size) {
		return ErrExceedQuota
	}

	f, err := b.file_data_repo.Create(ref.Path, strconv.FormatInt(user_agent.ID, 10))

	if err != nil {
		return err
	}

	io.Copy(f, src)
	f.Close()
	user_agent.FileQuota.Add(size)
	b.user_agent_repo.Update(user_agent.ID, *user_agent)

	return nil
}

func (b BogFileService) OpenOutFile(ref FileReference) (BogOutFile, error) {
	user_agent, err := b.user_agent_repo.GetByName(ref.UserAgent)
	if err == ErrNotExists {
		return nil, err
	}

	f, err := b.file_data_repo.Open(ref.Path, strconv.FormatInt(user_agent.ID, 10))

	if err != nil {
		return nil, err
	}

	return f, nil
}