//
//  ConvertAudioFile.m
//  Expert
//
//  Created by xuxiwen on 2017/3/21.
//  Copyright © 2017年 xuxiwen. All rights reserved.
//

#import "ConvertAudioFile.h"
#import <lame/lame.h>

@interface ConvertAudioFile ()
@property (nonatomic, assign) BOOL stopRecord;
@end

@implementation ConvertAudioFile

/**
 get instance obj
 
 @return ConvertAudioFile instance
 */
+ (instancetype)sharedInstance {
    static ConvertAudioFile *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[ConvertAudioFile alloc] init];
    });
    return instance;
}

/**
 ConvertMp3
 
 @param cafFilePath caf FilePath
 @param mp3FilePath mp3 FilePath
 @param sampleRate sampleRate (same record sampleRate set)
 @param callback callback result
 */
//- (void)conventToMp3WithCafFilePath:(NSString *)cafFilePath
//                        mp3FilePath:(NSString *)mp3FilePath
//                         sampleRate:(int)sampleRate
//                           callback:(void(^)(BOOL result))callback
//{
//
//        NSLog(@"convert begin!!");
//    __weak typeof(self) weakself = self;
//    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//
//        weakself.stopRecord = NO;
//
//        @try {
//
//            int read, write;
//
//            FILE *pcm = fopen([cafFilePath cStringUsingEncoding:NSASCIIStringEncoding], "rb");
//            FILE *mp3 = fopen([mp3FilePath cStringUsingEncoding:NSASCIIStringEncoding], "wb+");
//
//            const int PCM_SIZE = 8192;
//            const int MP3_SIZE = 8192;
//            short int pcm_buffer[PCM_SIZE * 2];
//            unsigned char mp3_buffer[MP3_SIZE];
//
//            lame_t lame = lame_init();
//            lame_set_in_samplerate(lame, sampleRate);
//            lame_set_VBR(lame, vbr_default);
//            lame_init_params(lame);
//
//            long curpos;
//            BOOL isSkipPCMHeader = NO;
//
//            do {
//                curpos = ftell(pcm);
//                long startPos = ftell(pcm);
//                fseek(pcm, 0, SEEK_END);
//                long endPos = ftell(pcm);
//                long length = endPos - startPos;
//                fseek(pcm, curpos, SEEK_SET);
//
//                if (length > PCM_SIZE * 2 * sizeof(short int)) {
//
//                    if (!isSkipPCMHeader) {
//                        //Uump audio file header, If you do not skip file header
//                        //you will heard some noise at the beginning!!!
//                        fseek(pcm, 4 * 1024, SEEK_CUR);
//                        isSkipPCMHeader = YES;
//                        NSLog(@"skip pcm file header !!!!!!!!!!");
//                    }
//
//                    read = (int)fread(pcm_buffer, 2 * sizeof(short int), PCM_SIZE, pcm);
//                    write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, MP3_SIZE);
//                    fwrite(mp3_buffer, write, 1, mp3);
////                    NSLog(@"read %d bytes", write);
//                } else {
//                    [NSThread sleepForTimeInterval:0.05];
////                    NSLog(@"sleep");
//                }
//
//            } while (! weakself.stopRecord);
//
//            read = (int)fread(pcm_buffer, 2 * sizeof(short int), PCM_SIZE, pcm);
//            write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
//
//            NSLog(@"read %d bytes and flush to mp3 file", write);
//            lame_mp3_tags_fid(lame, mp3);
//
//            lame_close(lame);
//            fclose(mp3);
//            fclose(pcm);
//        }
//        @catch (NSException *exception) {
//            NSLog(@"%@", [exception description]);
//            if (callback) {
//                callback(NO);
//            }
//        }
//        @finally {
//            if (callback) {
//                callback(YES);
//            }
//            NSLog(@"convert mp3 finish!!! %@", mp3FilePath);
//        }
//    });
//
//}

/**
 send end record signal
 */
- (void)sendEndRecord {
    self.stopRecord = YES;
}

- (void)conventToMp3WithCafFilePath:(NSString *)cafFilePath
                        mp3FilePath:(NSString *)mp3FilePath
                         sampleRate:(int)sampleRate {
    __weak typeof(self) weakself = self;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        weakself.stopRecord = NO;
        @try {
            int read, write;
            FILE *pcm = fopen([cafFilePath cStringUsingEncoding:NSASCIIStringEncoding], "rb");
            FILE *mp3 = fopen([mp3FilePath cStringUsingEncoding:NSASCIIStringEncoding], "wb+");
            
            const int PCM_SIZE = 8192;
            const int MP3_SIZE = 8192;
            short int pcm_buffer[PCM_SIZE * 2];
            unsigned char mp3_buffer[MP3_SIZE];
            
            lame_t lame = lame_init();
            lame_set_in_samplerate(lame, sampleRate);
            lame_set_VBR(lame, vbr_default);
            lame_init_params(lame);
            
            long curpos;
            BOOL isSkipPCMHeader = NO;
            
            do {
                curpos = ftell(pcm);
                long startPos = ftell(pcm);
                fseek(pcm, 0, SEEK_END);
                long endPos = ftell(pcm);
                long length = endPos - startPos;
                fseek(pcm, curpos, SEEK_SET);
                
                if (length > PCM_SIZE * 2 * sizeof(short int)) {
                    
                    if (!isSkipPCMHeader) {
                        //Uump audio file header, If you do not skip file header
                        //you will heard some noise at the beginning!!!
                        fseek(pcm, 4 * 1024, SEEK_CUR);
                        isSkipPCMHeader = YES;
                        NSLog(@"skip pcm file header !!!!!!!!!!");
                    }
                    
                    read = (int)fread(pcm_buffer, 2 * sizeof(short int), PCM_SIZE, pcm);
                    write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, MP3_SIZE);
                    fwrite(mp3_buffer, write, 1, mp3);
                    //                    NSLog(@"read %d bytes", write);
                } else {
                    [NSThread sleepForTimeInterval:0.05];
                    //                    NSLog(@"sleep");
                }
            } while (! weakself.stopRecord);
                NSLog(@"停止录音回调-----");
                read = (int)fread(pcm_buffer, 2 * sizeof(short int), PCM_SIZE, pcm);
                write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
                NSLog(@"read %d bytes and flush to mp3 file", write);
                lame_mp3_tags_fid(lame, mp3);
                lame_close(lame);
                fclose(mp3);
                fclose(pcm);
        }
        @catch (NSException *exception) {
            NSLog(@"出错了");
            NSLog(@"%@", [exception description]);
        
        }
        @finally {
            NSLog(@"转码完成");
            NSLog(@"convert mp3 finish!!! %@", mp3FilePath);
        }
    });
}

#pragma mark - ----------------------------------

// 这是录完再转码的方法, 如果录音时间比较长的话,会要等待几秒...
// Use this FUNC convent to mp3 after record

+ (void)conventToMp3WithCafFilePath:(NSString *)cafFilePath
                        mp3FilePath:(NSString *)mp3FilePath
                         sampleRate:(int)sampleRate
                           callback:(void(^)(BOOL result))callback
{
    
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        
        @try {
            int read, write;
            
            FILE *pcm = fopen([cafFilePath cStringUsingEncoding:1], "rb");  //source 被转换的音频文件位置
            fseek(pcm, 4*1024, SEEK_CUR);                                   //skip file header
            FILE *mp3 = fopen([mp3FilePath cStringUsingEncoding:1], "wb+");  //output 输出生成的Mp3文件位置
            
            const int PCM_SIZE = 8192;
            const int MP3_SIZE = 8192;
            short int pcm_buffer[PCM_SIZE*2];
            unsigned char mp3_buffer[MP3_SIZE];
            
            lame_t lame = lame_init();
            lame_set_num_channels(lame,1);//设置1为单通道，默认为2双通道
            lame_set_in_samplerate(lame, sampleRate);
            lame_set_VBR(lame, vbr_default);
            lame_init_params(lame);
            
            do {
                
                read = (int)fread(pcm_buffer, 2*sizeof(short int), PCM_SIZE, pcm);
                if (read == 0) {
                write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);

                } else {
                    write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, MP3_SIZE);
                }
                
                fwrite(mp3_buffer, write, 1, mp3);

            } while (read != 0);

            lame_mp3_tags_fid(lame, mp3);

            lame_close(lame);
            fclose(mp3);
            fclose(pcm);
        }
        @catch (NSException *exception) {
            NSLog(@"%@",[exception description]);
            if (callback) {
                callback(NO);
            }
        }
        @finally {
            NSLog(@"-----\n  MP3生成成功: %@   -----  \n", mp3FilePath);
            if (callback) {
                callback(YES);
            }
        }
    });
}

@end