#include "sort.h"

#include <fcntl.h>
#include <htslib/sam.h>
#include <htslib/thread_pool.h>
#include <klib/kthread.h>
#include <math.h>
#include <pthread.h>
#include <spdlog/spdlog.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <unistd.h>
#include <zlib.h>

#include <algorithm>
#include <string>

#include "const_val.h"
#include "sam_io.h"
#include "sort_args.h"
#include "sort_impl.h"
#include "util/profiling.h"
#include "util/yarn.h"

#include "process_header.h"
#include "phase_1.h"
#include "phase_2.h"
#include "compress.h"
#include "decompress.h"

using std::string;

#define BAM_BLOCK_SIZE 16L * 1024 * 1024

namespace nsgv {

SortArg gSortArg; // 参数
HeaderBuf gInHdr; // 输入文件的header
bool gIsBigEndian;
DataBuffer gMarginBuf; // 用于存放跨两个gz block的解压数据

};  // namespace nsgv

struct BamSortData {
    uint16_t flag;
    uint16_t qnameLen;
    uint16_t bamLen;
    int32_t tid;
    int64_t pos;
    uint8_t *uDataPos;
    char *qname;  // pointer to qname
};


/* 将bam文件内容读取到buf，解析buf中的gz block长度信息 */
static size_t doFirstPipeReadFile(FirstPipeArg &p, DataBuffer &halfBlock, FILE *fpr) {
    ReadBuffer &readData = p.readData[p.readOrder % p.READ_BUF_NUM];
    size_t readState = 0;
    size_t curReadPos = 0;
    int blockLen = 0;
    int maxBlockLen = 0;

    readState = fread(readData.dataBuf, 1, readData.readBufSize, fpr);
    if (readState == 0) { return 0; }

    readData.startAddrArr.clear();

    /* 处理上一个不完整的block */ // 需要一个额外的空间来保存上一个不完整的block数据，因为readbuffer里的data和block都会用来解析，而且解析之后都会清空。
    if (halfBlock.readPos > 0) {  // 上一轮有剩余
        if (halfBlock.readPos < BLOCK_HEADER_LENGTH) {  // 上一轮剩余数据不满足解析block长度信息
            memcpy(&halfBlock.data[halfBlock.readPos], readData.dataBuf, BLOCK_HEADER_LENGTH - halfBlock.readPos);
            halfBlock.curLen = unpackInt16(&halfBlock.data[16]) + 1;  // 更新一下剩余block的真正长度
            // spdlog::info("last remain, blocklen: {}, last load: {}", halfBlock.curLen, halfBlock.readPos);
        }
        memcpy(readData.blockBuf, halfBlock.data, halfBlock.readPos);
        curReadPos = halfBlock.curLen - halfBlock.readPos;  // curlen保存上一个block的长度，readPos保存上一个block在上一次读取中的长度
        memcpy(&readData.blockBuf[halfBlock.readPos], readData.dataBuf, curReadPos);  // 将不完整的block剩余数据拷贝到curBlock
        readData.startAddrArr.push_back(readData.blockBuf);
    }
    /* 解析读入buf中的文件数据，计算包含的每个block的长度信息和起始地址 */
    while (curReadPos + BLOCK_HEADER_LENGTH <= readState) { /* 确保能解析block长度 */
        blockLen = unpackInt16(&readData.dataBuf[curReadPos + 16]) + 1;
        if (blockLen > maxBlockLen) { maxBlockLen = blockLen; }
        if (curReadPos + blockLen <= readState) { /* 完整的block数据在buf里 */
            readData.startAddrArr.push_back(&readData.dataBuf[curReadPos]);
            curReadPos += blockLen;
        } else {
            break; /* 当前block数据不完整，一部分在还没读入的file数据里 */
        }
    }
    /* 如果buf中包含不完整的block数据，先保存一下，放到下一轮里去处理 */
    halfBlock.readPos = readState - curReadPos;
    halfBlock.curLen = blockLen;
    if (halfBlock.readPos > 0) {
        memcpy(halfBlock.data, &readData.dataBuf[curReadPos], halfBlock.readPos);  // 将不完整的block拷贝到halfBlock
    }

    // spdlog::info("block num-1: {}", readData.startAddrArr.size());
    //spdlog::info("read order: {}, max block len: {}", p.readOrder, maxBlockLen);
    
    return readState;
}


/* FirstPipe step-1 读取文件线程 */
static void *firstPipeReadFile(void *data) {
    FirstPipeArg &p = *(FirstPipeArg *)data;
    /* 1. set up */
    FILE *fpr = fopen(nsgv::gSortArg.INPUT_FILE.c_str(), "rb");
    parseSamHeader(fpr, nsgv::gInHdr);
    size_t fileSize = 0;
    DataBuffer halfBlock(SINGLE_BLOCK_SIZE);

    /* 2. do the work */
    while (true) {
        // self dependency
        yarn::DEPENDENCY_NOT_TO_BE(p.readSig, p.READ_BUF_NUM);

        PROF_G_BEG(read);
        size_t readState = doFirstPipeReadFile(p, halfBlock, fpr);
        PROF_G_END(read);

        if (readState == 0) {
            yarn::SIGNAL_FINISH(p.readSig, p.readFinish);
            break;
        }

        // update self status
        yarn::UPDATE_SIG_ORDER(p.readSig, p.readOrder);

        fileSize += readState;
    }

    spdlog::info("read file order: {}, file size: {}", p.readOrder, fileSize);
    /* 3. clean up */
    fclose(fpr);
    return nullptr;
}

static int parseBam(uint8_t* addr, bam1_t* b) {
    bam1_core_t* c = &b->core;
    int32_t block_len, ret, i;
    uint32_t new_l_data;
    uint8_t tmp[32], *x;

    b->l_data = 0;
    memcpy(&block_len, addr, 4);
    if (nsgv::gIsBigEndian)
        ed_swap_4p(&block_len);
    if (block_len < 32)
        return -4;  // block_len includes core data
    x = addr + 4;

    c->tid = le_to_u32(x);
    c->pos = le_to_i32(x + 4);
    uint32_t x2 = le_to_u32(x + 8);
    c->bin = x2 >> 16;
    c->qual = x2 >> 8 & 0xff;
    c->l_qname = x2 & 0xff;
    c->l_extranul = (c->l_qname % 4 != 0) ? (4 - c->l_qname % 4) : 0;
    uint32_t x3 = le_to_u32(x + 12);
    c->flag = x3 >> 16;
    c->n_cigar = x3 & 0xffff;
    c->l_qseq = le_to_u32(x + 16);
    c->mtid = le_to_u32(x + 20);
    c->mpos = le_to_i32(x + 24);
    c->isize = le_to_i32(x + 28);
#if 0
    new_l_data = block_len - 32 + c->l_extranul;
    if (new_l_data > INT_MAX || c->l_qseq < 0 || c->l_qname < 1)
        return -4;
    if (((uint64_t)c->n_cigar << 2) + c->l_qname + c->l_extranul + (((uint64_t)c->l_qseq + 1) >> 1) + c->l_qseq > (uint64_t)new_l_data)
        return -4;
    if (realloc_bam_data(b, new_l_data) < 0)
        return -4;
    b->l_data = new_l_data;

    if (bgzf_read_small(fp, b->data, c->l_qname) != c->l_qname)
        return -4;
    if (b->data[c->l_qname - 1] != '\0') {  // try to fix missing nul termination
        if (fixup_missing_qname_nul(b) < 0)
            return -4;
    }
    for (i = 0; i < c->l_extranul; ++i) b->data[c->l_qname + i] = '\0';
    c->l_qname += c->l_extranul;
    if (b->l_data < c->l_qname || bgzf_read_small(fp, b->data + c->l_qname, b->l_data - c->l_qname) != b->l_data - c->l_qname)
        return -4;
    if (fp->is_be)
        swap_data(c, b->l_data, b->data, 0);
    if (bam_tag2cigar(b, 0, 0) < 0)
        return -4;

    // TODO: consider making this conditional
    if (c->n_cigar > 0) {  // recompute "bin" and check CIGAR-qlen consistency
        hts_pos_t rlen, qlen;
        bam_cigar2rqlens(c->n_cigar, bam_get_cigar(b), &rlen, &qlen);
        if ((b->core.flag & BAM_FUNMAP) || rlen == 0)
            rlen = 1;
        b->core.bin = hts_reg2bin(b->core.pos, b->core.pos + rlen, 14, 5);
        // Sanity check for broken CIGAR alignments
        if (c->l_qseq > 0 && !(c->flag & BAM_FUNMAP) && qlen != c->l_qseq) {
            hts_log_error("CIGAR and query sequence lengths differ for %s", bam_get_qname(b));
            return -4;
        }
    }
#endif
    return 4 + block_len;
}

// multi-thread uncompress bam blocks
static void mtUncompressBlock(void *data, long idx, int tid) {
    PROF_T_BEG(mem_copy);

    UncompressData& p = *(UncompressData*)data;
    ReadBuffer &readData = *p.readDataPtr;

    auto &blockItemArr = p.blockItemArr[tid];
    auto &bamItemArr = p.bamItemArr[tid];

    auto &blockItem = blockItemArr.add();
    uint8_t *block = readData.startAddrArr[idx];

    size_t dlen = SINGLE_BLOCK_SIZE;  // 65535
    int block_length = unpackInt16(&block[16]) + 1;
    uint32_t crc = le_to_u32(block + block_length - 8);
    int ret = bgzfUncompress(blockItem.data, &dlen, (Bytef *)block + BLOCK_HEADER_LENGTH,
                             block_length - BLOCK_HEADER_LENGTH, crc);
    if (ret != 0) {
        spdlog::error("uncompress error, block id: {}, len: {}, ret: {}", idx, block_length, ret);
        exit(0);
    }
    blockItem.blockId = idx;
    blockItem.blockLen = dlen;
    uint32_t nextBamStart = 0;
    uint32_t bamLen = 0;
    uint32_t bamNum = 0;

    /* 解析每个bam */
    while (nextBamStart + 4 <= blockItem.blockLen) {
        OneBam& bam = bamItemArr.add();

        bam.blockThread = &blockItemArr;
        bam.blockIdx = blockItemArr.curIdx - 1;
        bam.offset = nextBamStart;
        uint8_t *curAddr = &blockItem.data[nextBamStart];
#if 0
        nextBamStart += parseBam(curAddr, &bam.b);
        ++bamNum;
#else
        memcpy(&bamLen, curAddr, 4);
        curAddr += 4;
        if (nsgv::gIsBigEndian) ed_swap_4p(&bamLen);
        bam.bamLen = bamLen;
        bam.tid = le_to_u32(curAddr);
        bam.pos = le_to_i32(curAddr + 4);
        uint32_t x2 = le_to_u32(curAddr + 8);
        bam.qnameLen = x2 & 0xff;

        // spdlog::info("bam len: {}, bam struct len: {}", bamLen, sizeof(OneBam));
        // spdlog::info("bam name: {}, bam name len: {}", string((char*)(blockItem.data + bam.offset + OneBam::QnameOffset), bam.qnameLen), bam.qnameLen);
        nextBamStart += 4 + bamLen;
        ++bamNum;
#endif
    }
    // spdlog::info("bam num: {}", bamNum);
    if (nextBamStart != blockItem.blockLen) {
        spdlog::error("Block content does not contain integer number of bam records!");
        exit(0);
    }
    blockItem.bamNum = bamNum;
    blockItemArr.bamNum += bamNum;

    // 判断是否超过内存阈值，只要有一个超过阈值，就转入下一阶段，进行排序和合并，但是也得把这一轮数据解压处理完
    if (blockItemArr.curIdx * SINGLE_BLOCK_SIZE * BLOCK_MEM_FACTOR >= p.father->singleThreadBytes) {
        p.father->uncompressBufFull = 1;
    } else {
        // spdlog::info("block arr: {}, single thread: {}", blockItemArr.blockArr.size() * SINGLE_BLOCK_SIZE, p.father->singleThreadBytes);
    }
    PROF_T_END(tid, mem_copy);
}

// multi-thread uncompress bam blocks
static void mtUncompressBlockBatch(void* data, long idx, int tid) {
    PROF_T_BEG(mem_copy);
    UncompressData& p = *(UncompressData*)data;
    ReadBuffer& readData = *p.readDataPtr;

    int startIdx = START_IDX(idx, nsgv::gSortArg.NUM_THREADS, readData.startAddrArr.size());
    int stopIdx = STOP_IDX(idx, nsgv::gSortArg.NUM_THREADS, readData.startAddrArr.size());

    auto& blockItemArr = p.blockItemArr[tid];
    auto& bamItemArr = p.bamItemArr[tid];

    blockItemArr.add(stopIdx - startIdx);

    for (int i = startIdx; i < stopIdx; ++i) {
        auto& blockItem = blockItemArr.blockArr[blockItemArr.curIdx++];

        uint8_t* block = readData.startAddrArr[i];

        size_t dlen = SINGLE_BLOCK_SIZE;  // 65535
        int block_length = unpackInt16(&block[16]) + 1;
        uint32_t crc = le_to_u32(block + block_length - 8);
        int ret = bgzfUncompress(blockItem.data, &dlen, (Bytef*)block + BLOCK_HEADER_LENGTH, block_length - BLOCK_HEADER_LENGTH, crc);
        if (ret != 0) {
            spdlog::error("uncompress error, block id: {}, len: {}, ret: {}", idx, block_length, ret);
            exit(0);
        }
        blockItem.blockId = i;
        blockItem.blockLen = dlen;
        uint32_t nextBamStart = 0;
        uint32_t bamLen = 0;
        uint32_t bamNum = 0;

#if 1
        /* 解析每个bam */
        while (nextBamStart + 4 <= blockItem.blockLen) {
            bamItemArr.bamArr.push_back(OneBam());
            OneBam& bam = bamItemArr.bamArr.back();

            //bam.addr = &blockItem.data[nextBamStart];
            uint8_t* curAddr = &blockItem.data[nextBamStart];
            memcpy(&bamLen, curAddr, 4);
            curAddr += 4;
            if (nsgv::gIsBigEndian)
                ed_swap_4p(&bamLen);
            bam.bamLen = bamLen;
            bam.tid = le_to_u32(curAddr);
            bam.pos = le_to_i32(curAddr + 4);
            uint32_t x2 = le_to_u32(curAddr + 8);
            bam.qnameLen = x2 & 0xff;
            //bam.qnameAddr = (char*)(curAddr + 32);

            // spdlog::info("bam len: {}, bam struct len: {}", bamLen, sizeof(OneBam));
            nextBamStart += 4 + bamLen;
            ++bamNum;
        }
        if (nextBamStart != blockItem.blockLen) {
            spdlog::error("Block content does not contain integer number of bam records!");
            exit(0);
        }
#endif
        blockItem.bamNum = bamNum;

    }
    // 判断是否超过内存阈值
    if (blockItemArr.curIdx * SINGLE_BLOCK_SIZE >= p.father->singleThreadBytes) {
        p.father->uncompressBufFull = 1;
    } else {
        // spdlog::info("block arr: {}, single thread: {}", blockItemArr.blockArr.size() * SINGLE_BLOCK_SIZE, p.father->singleThreadBytes);
    }
    PROF_T_END(tid, mem_copy);
}

// 线程内排序
static void mtInThreadSort(void* data, long idx, int tid) {
    UncompressData& p = *(UncompressData*)data;
    auto& bamItemArr = p.bamItemArr[tid];
    auto& arr = bamItemArr.bamArr;
    // 先按照坐标排序

#if 0
    if (tid == 0)
        spdlog::info("Before: {} {} {} {} {} {} {} {} {} {}", arr[0].pos, arr[1].pos, arr[2].pos, arr[3].pos, arr[4].pos, arr[5].pos, arr[6].pos,
                     arr[7].pos, arr[8].pos, arr[9].pos);
#endif

    if (nsgv::gSortArg.SORT_COORIDINATE) {
        std::sort(arr.begin(), arr.begin() + bamItemArr.curIdx, [](const OneBam& b1, const OneBam& b2) { return b1.pos < b2.pos; });
    } else if (nsgv::gSortArg.QUERY_NAME_TYPE == nsmd::QueryNameType::PICARD) {
        std::sort(arr.begin(), arr.begin() + bamItemArr.curIdx, [](const OneBam& b1, const OneBam& b2) {
            int cmp = 0;
            strncmp((char*)(b1.blockThread->blockArr[b1.blockIdx].data + b1.offset + OneBam::QnameOffset),
                    (char*)(b2.blockThread->blockArr[b2.blockIdx].data + b2.offset + OneBam::QnameOffset), std::min(b1.qnameLen, b2.qnameLen));
            if (cmp == 0)
                return b1.qnameLen < b2.qnameLen;
            return cmp < 0;
        });
    }

#if 0
    if (tid == 0)
        spdlog::info("After: {} {} {} {} {} {} {} {} {} {}", arr[0].pos, arr[1].pos, arr[2].pos, arr[3].pos, arr[4].pos, arr[5].pos, arr[6].pos,
                     arr[7].pos, arr[8].pos, arr[9].pos);
#endif

}

// 多线程压缩
static void mtCompressBlock(void* data, long idx, int tid) {
    FirstPipeArg &p = *(FirstPipeArg *)data;
    auto& barr = p.sortedBamArr;
    auto& t = p.taskArr[idx];
    auto& buf = p.threadBuf[tid];

    uint8_t block[SINGLE_BLOCK_SIZE] = {0};
    uint8_t compressBlock[SINGLE_BLOCK_SIZE] = {0};
    int curAddr = 0;
    for (int i = t.idx; i < t.idx + t.num; ++i) {
        // copy data
        memccpy(&block[curAddr], barr[i]->blockThread->blockArr[barr[i]->blockIdx].data + barr[i]->offset, 1, barr[i]->bamLen);
        curAddr += barr[i]->bamLen;
    }

    size_t dlen = BGZF_MAX_BLOCK_SIZE;
    // spdlog::info("len: {}", curAddr);
    bgzfCompress(block, &dlen, compressBlock, curAddr, -1);
    // 先放到自己线程内部的buf里

    // 然后在压缩完成之后，检测当前全局压缩序号，如果当前序号的block在自己线程内，则复制过去

}

/* 将gz block进行解压，并进行线程内排序 */
static void doFirstPipeUncompress(FirstPipeArg &p, int finish = 0) {
    // return;
    PROF_G_BEG(uncompress);
    ReadBuffer &readData = p.readData[p.uncompressOrder % p.READ_BUF_NUM];
    UncompressData &uncompressData = p.uncompressData[p.uncompressOrder % p.UNCOMPRESS_BUF_NUM];
    uncompressData.readDataPtr = &readData;

#if 1
    kt_for(p.numThread, mtUncompressBlock, &uncompressData, readData.startAddrArr.size());
#else
    kt_for(p.numThread, mtUncompressBlockBatch, &uncompressData, nsgv::gSortArg.NUM_THREADS);
#endif

    PROF_G_END(uncompress);

    // 判断是否超过内存阈值，只要有一个超过阈值，就转入下一阶段，进行排序和合并
    if (p.uncompressBufFull == 1 || finish) {

        spdlog::info("buf full - {}", p.mergeOrder);

        // spdlog::info("max mem: {}, single thread mem: {}", nsgv::gSortArg.MAX_MEM, p.singleThreadBytes);

        // sort，排序的时候应该线程利用率很高，此时不需要跟其他操作如压缩等进行重叠了
        PROF_G_BEG(sort);
        kt_for(p.numThread, mtInThreadSort, &uncompressData, nsgv::gSortArg.NUM_THREADS);
        PROF_G_END(sort);
        // merge
#if 0
        auto& bamArr = p.sortedBamArr;
        BamHeap<BamGreaterThan> heap;
        heap.Init(&uncompressData.bamItemArr);
        bamArr.resize(heap.Size());
        auto& taskArr = p.taskArr;
        taskArr.clear();

        const OneBam* bam = nullptr;
        uint64_t posAll = 0;
        int i = 0;
        ArrayInterval intv{0, 0};
        uint64_t blockBytes = 0;
        PROF_G_BEG(merge);
        while ((bam = heap.Pop()) != nullptr) {
            // posAll += bam->pos;
            //spdlog::info("pos: {}", bam->pos);
            bamArr[i++] = bam;
            blockBytes += bam->bamLen;
            if (blockBytes >= SINGLE_BLOCK_SIZE) {
                intv.num = i - 1 - intv.idx;
                taskArr.push_back(intv);
                intv.idx = i - 1;
                blockBytes = bam->bamLen;
            }
        }
        PROF_G_END(merge);
        spdlog::info("task size: {} {}", taskArr.size(), bamArr.size());
        if (i - 1 > intv.idx) {
            intv.num = i - 1 - intv.idx;
            taskArr.push_back(intv);
        }

        // spdlog::info("pos all: {}", posAll);
#endif
        // compress，此时并行压缩的多线程利用率应该很高了
        PROF_G_BEG(compress);
#if 0
        kt_for(p.numThread, mtCompressBlock, &p, taskArr.size());
#endif

        for (auto &blockItemArr : uncompressData.blockItemArr) {
            p.bamNum += blockItemArr.bamNum;
        }

        uncompressData.ResetBlockArr();
        uncompressData.ResetBamArr();
        p.uncompressBufFull = 0;
        p.mergeOrder++;
        for(auto &buf : p.threadBuf) {
            buf.curLen = 0;
        }
        PROF_G_END(compress);

        // 压缩完之后应该写入中间文件，这个应该可以overlap
    }
    // 等处理完这些数据之后，进入新一轮的解压和归并排序压缩输出中间文件。
    
    // auto &bam = uncompressData.bamItemArr[0].bamArr.back();
    // string qname(bam.qnameAddr, bam.qnameLen);
    // spdlog::info("bam name:{}", qname);
}

/* FirstPipe step-2 并行解压gz blocks*/
static void *firstPipeUncompress(void *data) {
    FirstPipeArg &p = *(FirstPipeArg *)data;

    /* 2. do the work */
    while (true) {
        // previous dependency
        yarn::DEPENDENCY_NOT_TO_BE(p.readSig, 0);
        // self dependency
        yarn::DEPENDENCY_NOT_TO_BE(p.uncompressSig, p.UNCOMPRESS_BUF_NUM);

        if (p.readFinish) {
            while (p.uncompressOrder < p.readOrder) {
                yarn::DEPENDENCY_NOT_TO_BE(p.uncompressSig, p.UNCOMPRESS_BUF_NUM);
                doFirstPipeUncompress(p, 1);
                yarn::UPDATE_SIG_ORDER(p.uncompressSig, p.uncompressOrder);
            }
            yarn::SIGNAL_FINISH(p.uncompressSig, p.uncompressFinish);
            break;
        }

        doFirstPipeUncompress(p);

        // update status
        yarn::CONSUME_SIGNAL(p.readSig);
        yarn::UPDATE_SIG_ORDER(p.uncompressSig, p.uncompressOrder);
    }

    spdlog::info("uncompress order: {}", p.uncompressOrder);
    return nullptr;
}

/* 将并行解压的数据放到一起，解析，到容量阈值后，进行排序并输出到中间文件 */
void dofirstPipeWrite(FirstPipeArg &p) {
    PROF_G_BEG(sort);
    UncompressData &uncompressData = p.uncompressData[p.writeOrder % p.UNCOMPRESS_BUF_NUM];

    size_t blockNum = 0;
    for (int i = 0; i < p.numThread; ++i) {
        blockNum += uncompressData.blockItemArr[i].curIdx;
    }
    size_t bamNum = blockNum * 256;

    size_t curBlockBamMemSize = blockNum * SINGLE_BLOCK_SIZE + bamNum * 32;
    /* 内存使用量达到阈值后，进行排序 */
    if (curBlockBamMemSize > nsgv::gSortArg.MAX_MEM / 2) {
        //uncompressData.ResetBlockArr();
        //uncompressData.ResetBamArr();
    }

    //spdlog::info("block num: {}, bam num: {}, block size: {}, bam size: {}", blockNum, bamNum, blockBytes, bamNum * 32);
    // spdlog::info("block num: {}, bam num: {}, block size: {}, bam size: {}", blockNum, bamNum, blockNum * SINGLE_BLOCK_SIZE, bamNum * 32);
    PROF_G_END(sort);
}

/* FirstPipe step-3 串行写入中间文件（已经压缩好） */
static void *firstPipeWrite(void *data) {
    FirstPipeArg &p = *(FirstPipeArg *)data;

    while (true) {
        yarn::DEPENDENCY_NOT_TO_BE(p.uncompressSig, 0);

        if (p.uncompressFinish) {
            spdlog::info("uncompress finish, cur sort order: {}", p.writeOrder);
            while (p.writeOrder < p.uncompressOrder) {
                dofirstPipeWrite(p);
                p.writeOrder += 1;
            }
            /* 需要检测一下buf中是否还有数据，如果还有，则需要进行排序，可以不输出到中间文件，直接进行second-pipe的归并排序 */
            break;
        }

        dofirstPipeWrite(p);

        p.writeOrder += 1;

        // update status
        yarn::CONSUME_SIGNAL(p.uncompressSig);
    }

    spdlog::info("merge sort order: {}", p.writeOrder);
    return nullptr;
}

/* 对bam文件进行排序第一阶段，线程内排序，线程间merge，输入到中间bam文件 */
static void bamSortFirstPipe() {
    /* set up*/
    FirstPipeArg firstPipeArg;
    firstPipeArg.numThread = nsgv::gSortArg.NUM_THREADS;
    firstPipeArg.singleThreadBytes = nsgv::gSortArg.MAX_MEM / firstPipeArg.numThread;
    spdlog::info("max mem: {}, single thread mem: {}", nsgv::gSortArg.MAX_MEM, firstPipeArg.singleThreadBytes);
    const size_t kReadBufSize = 1L * 1024 * 1024 * firstPipeArg.numThread; // 平均每线程1M缓冲区，累加起来，用来读入文件（BAM/SAM）（相对解压之后的缓冲区，大小可以忽略）
    for (int i = 0; i<firstPipeArg.READ_BUF_NUM; ++i) {
        firstPipeArg.readData[i].Resize(kReadBufSize);
    }

    // 根据最大内存参数，计算初始化开辟的空间
    int blockInitNum = nsgv::gSortArg.MAX_MEM / nsgv::gSortArg.NUM_THREADS / SINGLE_BLOCK_SIZE / BLOCK_MEM_FACTOR;
    spdlog::info("Init block num: {}", blockInitNum);
    for (int i = 0; i < firstPipeArg.UNCOMPRESS_BUF_NUM; ++i) {
        firstPipeArg.uncompressData[i].Resize(firstPipeArg.numThread, blockInitNum);
    }

    PROF_G_BEG(mid_all);
    /* create threads */
    pthread_t pipeThreadIdArr[3]; // 3-stage pipeline
    pthread_create(&pipeThreadIdArr[0], NULL, firstPipeReadFile, &firstPipeArg);
    pthread_create(&pipeThreadIdArr[1], NULL, firstPipeUncompress, &firstPipeArg);
    pthread_create(&pipeThreadIdArr[2], NULL, firstPipeWrite, &firstPipeArg);

    for (int i = 0; i < 3; ++i) pthread_join(pipeThreadIdArr[i], NULL);

    spdlog::info("all bams num: {}", firstPipeArg.bamNum);

    PROF_G_END(mid_all);
}

/* IO同步的方式进行排序 */
static void bamSortSerialFirstPipe() {
    /* set up*/
    FirstPipeArg firstPipeArg;
    firstPipeArg.numThread = nsgv::gSortArg.NUM_THREADS;
    const size_t kReadBufSize = 1L * 1024 * 1024 * firstPipeArg.numThread;
    for (int i = 0; i < firstPipeArg.READ_BUF_NUM; ++i) {
        firstPipeArg.readData[i].Resize(kReadBufSize);
    }
    for (int i = 0; i < firstPipeArg.UNCOMPRESS_BUF_NUM; ++i) {
        firstPipeArg.uncompressData[i].Resize(firstPipeArg.numThread, 128);
    }

    /* 1. read file */
    FILE *fpr = fopen(nsgv::gSortArg.INPUT_FILE.c_str(), "rb");
    parseSamHeader(fpr, nsgv::gInHdr);
    size_t fileSize = 0;
    DataBuffer halfBlock(SINGLE_BLOCK_SIZE);

    /* 2. do the work */
    while (true) {
        size_t readState = doFirstPipeReadFile(firstPipeArg, halfBlock, fpr);
        doFirstPipeUncompress(firstPipeArg);
        dofirstPipeWrite(firstPipeArg);
        if (readState == 0) break;
        fileSize += readState;
    }

    /* 3. clean up */
    fclose(fpr);
}

/* 对sam文件进行排序 */
static void samSortFirstPipe() {

}


// 排序的入口函数，entry function
int doSort() {

#if 1
    nsgv::gIsBigEndian = ed_is_big();
    // 第一轮排序，外排到多个中间文件
    // bamSortFirstPipe();

    phase1Pipeline();

    spdlog::info("OneBam size: {}", sizeof(OneBam));
    // bamSortSerialFirstPipe();
#else

    /* 打开输入bam文件 */
    samFile *inBamFp = sam_open_format(nsgv::gSortArg.INPUT_FILE.c_str(), "r", nullptr);
    if (!inBamFp) {
        spdlog::error("[{}] load sam/bam file failed.\n", __func__);
        return -1;
    }
    hts_set_opt(inBamFp, HTS_OPT_BLOCK_SIZE, BAM_BLOCK_SIZE);
    sam_hdr_t *inBamHdr = sam_hdr_read(inBamFp);  // 读取header
    
    htsThreadPool htsPoolRead = {NULL, 0};        // 多线程读取，创建线程池
    htsPoolRead.pool = hts_tpool_init(nsgv::gSortArg.NUM_THREADS);
    if (!htsPoolRead.pool) {
        spdlog::error("[{}] failed to set up thread pool", __LINE__);
        sam_close(inBamFp);
        return -1;
    }
    hts_set_opt(inBamFp, HTS_OPT_THREAD_POOL, &htsPoolRead);

    // 测试读取bam的速度

    int max_bam_len = 0;
    bam1_t *bamp = bam_init1();
    uint64_t bam_num = 0;
    while (sam_read1(inBamFp, inBamHdr, bamp) >= 0) {
        bam_num++;
        if (max_bam_len < bamp->l_data) max_bam_len = bamp->l_data;
        if (bamp->l_data > 1000) {
            spdlog::info("large record len: {}", bamp->l_data);
        }
    }
    sam_close(inBamFp);
    spdlog::info("max record len: {}", max_bam_len);
    spdlog::info("bam num: {}", bam_num);

#endif

    return 0;
}