// Copyright 2024 Kelvin Clement Mwinuka
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package sugardb

import (
	"strconv"

	"github.com/echovault/sugardb/internal"
)

// SetRange replaces a portion of the string at the provided key starting at the offset with a new string.
// If the string does not exist, a new string is created.
//
// Returns: The length of the new string as an integers.
//
// Errors:
//
// - "value at key <key> is not a string" when the key provided does not hold a string.
func (server *SugarDB) SetRange(key string, offset int, new string) (int, error) {
	b, err := server.handleCommand(server.context, internal.EncodeCommand([]string{"SETRANGE", key, strconv.Itoa(offset), new}), nil, false, true)
	if err != nil {
		return 0, err
	}
	return internal.ParseIntegerResponse(b)
}

// StrLen returns the length of the string at the provided key.
//
// Returns: The length of the string as an integer.
//
// Errors:
//
// - "value at key <key> is not a string" - when the value at the keys is not a string.
func (server *SugarDB) StrLen(key string) (int, error) {
	b, err := server.handleCommand(server.context, internal.EncodeCommand([]string{"STRLEN", key}), nil, false, true)
	if err != nil {
		return 0, err
	}
	return internal.ParseIntegerResponse(b)
}

// SubStr returns a substring from the string at the key.
// The start and end indices are integers that specify the lower and upper bound respectively.
//
// Returns: The substring from the start index to the end index.
//
// Errors:
//
// - "key <key> does not exist" - when the key does not exist.
//
// - "value at key <key> is not a string" - when the value at the keys is not a string.
func (server *SugarDB) SubStr(key string, start, end int) (string, error) {
	b, err := server.handleCommand(server.context, internal.EncodeCommand([]string{"SUBSTR", key, strconv.Itoa(start), strconv.Itoa(end)}), nil, false, true)
	if err != nil {
		return "", err
	}
	return internal.ParseStringResponse(b)
}

// GetRange works the same as SubStr.
func (server *SugarDB) GetRange(key string, start, end int) (string, error) {
	b, err := server.handleCommand(server.context, internal.EncodeCommand([]string{"GETRANGE", key, strconv.Itoa(start), strconv.Itoa(end)}), nil, false, true)
	if err != nil {
		return "", err
	}
	return internal.ParseStringResponse(b)
}

// Append concatenates the string at the key with the value provided
// If the key does not exists it functions like a SET command
//
// Returns: The lenght of the new concatenated value at key
//
// Errors:
//
// - "value at key <key> is not a string" - when the value at the keys is not a string.
func (server *SugarDB) Append(key string, value string) (int, error) {
	b, err := server.handleCommand(server.context, internal.EncodeCommand([]string{"APPEND", key, value}), nil, false, true)
	if err != nil {
		return 0, err
	}
	return internal.ParseIntegerResponse(b)
}