package internal

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"

	"go.salty.im/saltyim"
)

const (
	wellknownPath    = ".well-known/salty"
	avatarsPath      = "avatars"
	avatarResolution = 80 // 80x80 px
	blobsPath        = "blobs"
)

var (
	ErrAddressExists = errors.New("error: address already exists")
	ErrBlobNotFound  = errors.New("error: blob not found")
)

func CreateConfig(conf *Config, hash string, key string) error {
	p := filepath.Join(conf.Data, wellknownPath)
	p = saltyim.FixUnixHome(p)

	fn := filepath.Join(p, fmt.Sprintf("%s.json", hash))
	if FileExists(fn) {
		return ErrAddressExists
	}

	if err := os.MkdirAll(p, 0755); err != nil {
		return fmt.Errorf("error creating config paths %s: %w", p, err)
	}

	ulid, err := saltyim.GenerateULID()
	if err != nil {
		return fmt.Errorf("error generating ulid")
	}

	endpointURL := *conf.baseURL
	endpointURL.Path = fmt.Sprintf("/inbox/%s", ulid)

	config := saltyim.Config{
		Endpoint: endpointURL.String(),
		Key:      key,
	}

	data, err := json.Marshal(config)
	if err != nil {
		return fmt.Errorf("error serializing config")
	}

	if err := os.WriteFile(fn, data, 0644); err != nil {
		return fmt.Errorf("error writing config to %s: %w", fn, err)
	}

	return nil
}

func CreateOrUpdateAvatar(conf *Config, addr saltyim.Addr, contents []byte) error {
	p := filepath.Join(conf.Data, avatarsPath)
	p = saltyim.FixUnixHome(p)

	if err := os.MkdirAll(p, 0755); err != nil {
		return fmt.Errorf("error creating avatars paths %s: %w", p, err)
	}

	fn := filepath.Join(p, fmt.Sprintf("%s.png", addr.Hash()))

	if err := SaveAvatar(fn, bytes.NewBuffer(contents), avatarResolution); err != nil {
		return fmt.Errorf("error writing avatar %s: %w", fn, err)
	}

	return nil
}

func CreateOrUpdateBlob(conf *Config, key string, data []byte, signer string) error {
	p := filepath.Join(conf.Data, blobsPath, signer)
	p = saltyim.FixUnixHome(p)

	if err := os.MkdirAll(p, 0755); err != nil {
		return fmt.Errorf("error creating blobs paths %s: %w", p, err)
	}

	fn := filepath.Join(p, key)

	if err := os.WriteFile(fn, data, os.FileMode(0644)); err != nil {
		return fmt.Errorf("error writing blob %s: %w", fn, err)
	}

	return nil
}

func GetBlob(conf *Config, key string, signer string) (*saltyim.Blob, error) {
	p := filepath.Join(conf.Data, blobsPath, signer)
	p = saltyim.FixUnixHome(p)

	if err := os.MkdirAll(p, 0755); err != nil {
		return nil, fmt.Errorf("error creating blobs paths %s: %w", p, err)
	}

	fn := filepath.Join(p, key)

	if !FileExists(fn) {
		return nil, ErrBlobNotFound
	}

	return saltyim.OpenBlob(fn)
}

func DeleteBlob(conf *Config, key string, signer string) error {
	p := filepath.Join(conf.Data, blobsPath, signer)
	p = saltyim.FixUnixHome(p)

	if err := os.MkdirAll(p, 0755); err != nil {
		return fmt.Errorf("error creating blobs paths %s: %w", p, err)
	}

	fn := filepath.Join(p, key)

	if !FileExists(fn) {
		return ErrBlobNotFound
	}

	// TODO: Delete the .json properties metadata files too

	return os.Remove(fn)
}