/*
 *  Copyright (c) 2024 Your Name / Yggmail Contributor
 *
 *  This Source Code Form is subject to the terms of the Mozilla Public
 *  License, v. 2.0. If a copy of the MPL was not distributed with this
 *  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

package sqlite3

import (
	"database/sql"
	"fmt"

	"github.com/neilalexander/yggmail/internal/storage/types"
)

type TableAccounts struct {
	db            *sql.DB
	writer        *Writer
	selectAccount *sql.Stmt
	listAccounts  *sql.Stmt
	createAccount *sql.Stmt
	updateAccount *sql.Stmt
	deleteAccount *sql.Stmt
}

const accountsSchema = `
	CREATE TABLE IF NOT EXISTS accounts (
		pubkey      TEXT NOT NULL,
		aliases     TEXT,
		passwd_hash TEXT,
		private_key TEXT,
		PRIMARY KEY(pubkey)
	);
`

const accountsSelect = `
	SELECT pubkey, aliases, passwd_hash, private_key FROM accounts WHERE pubkey = $1
`

const accountsList = `
	SELECT pubkey, aliases, passwd_hash, private_key FROM accounts
`

const accountsCreate = `
	INSERT OR IGNORE INTO accounts (pubkey, aliases, passwd_hash, private_key) VALUES($1, $2, $3, $4)
`

const accountsUpdate = `
	UPDATE accounts SET aliases = $1, passwd_hash = $2, private_key = $3 WHERE pubkey = $4
`

const accountsDelete = `
	DELETE FROM accounts WHERE pubkey = $1
`

func NewTableAccounts(db *sql.DB, writer *Writer) (*TableAccounts, error) {
	t := &TableAccounts{
		db:     db,
		writer: writer,
	}

	_, err := db.Exec(accountsSchema)
	if err != nil {
		return nil, fmt.Errorf("db.Exec: %w", err)
	}

	t.selectAccount, err = db.Prepare(accountsSelect)
	if err != nil {
		return nil, fmt.Errorf("db.Prepare(accountsSelect): %w", err)
	}

	t.listAccounts, err = db.Prepare(accountsList)
	if err != nil {
		return nil, fmt.Errorf("db.Prepare(accountsList): %w", err)
	}

	t.createAccount, err = db.Prepare(accountsCreate)
	if err != nil {
		return nil, fmt.Errorf("db.Prepare(accountsCreate): %w", err)
	}

	t.updateAccount, err = db.Prepare(accountsUpdate)
	if err != nil {
		return nil, fmt.Errorf("db.Prepare(accountsUpdate): %w", err)
	}

	t.deleteAccount, err = db.Prepare(accountsDelete)
	if err != nil {
		return nil, fmt.Errorf("db.Prepare(accountsDelete): %w", err)
	}

	return t, nil
}

func (t *TableAccounts) AccountGet(pubkey string) (*types.Account, error) {
	row := t.selectAccount.QueryRow(pubkey)

	acc := &types.Account{}
	err := row.Scan(&acc.PublicKey, &acc.Aliases, &acc.PasswdHash, &acc.Privatekey)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, nil // Аккаунт не найден
		}
		return nil, fmt.Errorf("row.Scan: %w", err)
	}

	return acc, nil
}

func (t *TableAccounts) AccountList() ([]*types.Account, error) {
	rows, err := t.listAccounts.Query()
	if err != nil {
		return nil, fmt.Errorf("t.listAccounts.Query: %w", err)
	}
	defer rows.Close()

	var accounts []*types.Account
	for rows.Next() {
		acc := &types.Account{}
		if err := rows.Scan(&acc.PublicKey, &acc.Aliases, &acc.PasswdHash, &acc.Privatekey); err != nil {
			return nil, fmt.Errorf("rows.Scan: %w", err)
		}
		accounts = append(accounts, acc)
	}
	return accounts, nil
}

func (t *TableAccounts) AccountCreate(acc *types.Account) error {
	// TODO: Validate that PublicKey is a valid hex before storing
	return t.writer.Do(t.db, nil, func(txn *sql.Tx) error {
		_, err := t.createAccount.Exec(acc.PublicKey, acc.Aliases, acc.PasswdHash, acc.Privatekey)
		return err
	})
}

func (t *TableAccounts) AccountUpdate(acc *types.Account) error {
	// TODO: Ensure we don't accidentally overwrite PrivateKey with empty string if not provided in update
	return t.writer.Do(t.db, nil, func(txn *sql.Tx) error {
		_, err := t.updateAccount.Exec(acc.Aliases, acc.PasswdHash, acc.Privatekey, acc.PublicKey)
		return err
	})
}

func (t *TableAccounts) AccountDelete(pubkey string) error {
	// TODO: Delete associated mails in TableMails when an account is deleted?
	// Or use ON DELETE CASCADE in future schema migrations.
	return t.writer.Do(t.db, nil, func(txn *sql.Tx) error {
		_, err := t.deleteAccount.Exec(pubkey)
		return err
	})
}