package storage

import (
	"database/sql"
	"errors"
	"fmt"
	"log"

	"git.sp4ke.com/sp4ke/bit4sat/db"
	"github.com/jmoiron/sqlx"
	"github.com/mattn/go-sqlite3"
	"github.com/mediocregopher/radix/v3"
)

var DB = db.DB

const (
	DBUploadSchema = `
		CREATE TABLE IF NOT EXISTS upload (
			id serial PRIMARY KEY,
			upload_id varchar(9) NOT NULL,
			sha256 varchar(64) NOT NULL,
			file_name varchar(255) NOT NULL,
			file_type varchar(255) DEFAULT '',
			file_size integer NOT NULL,
			file_ext varchar(255) DEFAULT '',
			status integer DEFAULT 0 REFERENCES upload_status(type),
			UNIQUE (upload_id, sha256)
		);
	`

	DBUploadView = `
CREATE OR REPLACE VIEW upload_with_status
AS SELECT 
	upload.upload_id,
	upload.sha256,
	upload_status.status,
	upload.file_name,
	upload.file_type,
	upload.file_size,
	upload.file_ext
 FROM upload
JOIN upload_status ON
upload.status = upload_status.type
	`

	DBUploadStatusSchema = `CREATE TABLE IF NOT EXISTS upload_status
		(
		type INT NOT NULL PRIMARY KEY,
		status CHAR(255) NOT NULL UNIQUE
		)
	`

	QNewUpload = `INSERT INTO upload
	(upload_id, sha256, file_name, file_type, file_size, file_ext, status)
	VALUES
	(:upload_id, :sha256, :file_name, :file_type, :file_size, :file_ext, :status)`

	QSetStatus = `UPDATE upload SET status = :status WHERE upload_id = :upload_id `

	QGetByHashID = `SELECT  upload_id,
							sha256,
							file_name,
							file_type,
							file_size,
							file_ext,
							status
FROM upload WHERE sha256 = $1 AND upload_id = $2`
)

const (
	UpNew = iota
	UpStored
	UpWaitingPayment
	UpReady
)

var UploadStatus = map[int]string{
	UpNew:            "new upload",
	UpStored:         "stored",
	UpWaitingPayment: "waiting payment",
	UpReady:          "ready",
}

var (
	ErrDoesNotExist  = errors.New("does not exist")
	ErrAlreadyExists = errors.New("already exists")
)

type Upload struct {
	ID       string `db:"upload_id"`
	SHA256   string `db:"sha256"`
	FileName string `db:"file_name"`
	FileType string `db:"file_type"`
	FileSize int64  `db:"file_size"`
	FileExt  string `db:"file_ext"`
	Status   int    `db:"status"`
}

func CacheSetUploadStatus(id string, status int) error {
	key := fmt.Sprintf("upload_status_%s", id)

	return DB.Redis.Do(radix.FlatCmd(nil, "SET", key, status))
}

// Returns true if id exists in DB
func IdExists(id string) (exists bool, err error) {
	key := fmt.Sprintf("upload_status_%s", id)

	err = DB.Redis.Do(radix.Cmd(&exists, "EXISTS", key))

	return
}

// Get a file by upload id and hash
func GetByHashID(sha256 string, id string) (*Upload, error) {
	var up Upload

	err := DB.Sql.Get(&up, QGetByHashID, sha256, id)

	if err == sql.ErrNoRows {
		return nil, ErrDoesNotExist
	}

	if err != nil {
		return nil, err
	}

	return &up, nil
}

func (u *Upload) TxSetState(tx *sqlx.Tx, status int) error {
	_, err := tx.NamedExec(QSetStatus, u)

	if err != nil {
		return err
	}

	return nil
}

func (u *Upload) TxWrite(tx *sqlx.Tx) error {

	_, err := tx.NamedExec(QNewUpload, u)

	sqlErr, isSqlErr := err.(sqlite3.Error)

	if isSqlErr && sqlErr.Code == sqlite3.ErrConstraint {
		return ErrAlreadyExists
	}

	if err != nil {
		return err
	}

	return nil
}

func (u *Upload) Write() error {
	_, err := DB.Sql.NamedExec(QNewUpload, u)
	sqlErr, isSqlErr := err.(sqlite3.Error)
	if isSqlErr && sqlErr.Code == sqlite3.ErrConstraint {
		return ErrAlreadyExists
	}

	if err != nil {
		return err
	}

	return nil
}

func init() {
	_, err := DB.Sql.Exec(DBUploadStatusSchema)
	if err != nil {
		log.Fatal(err)
	}

	_, err = DB.Sql.Exec(DBUploadSchema)
	if err != nil {
		log.Fatal(err)
	}

	_, err = DB.Sql.Exec(DBUploadView)
	if err != nil {
		log.Fatal(err)
	}

	// Populate status types
	query := `INSERT INTO upload_status (type, status)
	 VALUES($1,$2) ON CONFLICT (type) DO UPDATE
				SET status = $3`
	for k, v := range UploadStatus {
		_, err := DB.Sql.Exec(query, k, v, v)
		if err != nil {
			sqlErr, ok := err.(sqlite3.Error)
			if ok && sqlErr.ExtendedCode == sqlite3.ErrConstraintUnique {
				log.Panic(err)
			}

			if !ok {
				log.Panic(err)
			}
		}
	}

}