// 一. 读取并解析recalibrate tables

// 二. 循环处理每一个read

// 1. 计算read的协变量covs

// 2. 根据read的协变量信息从recal tables获取对应的数据

// 3. 根据recal tables数据对read的每个碱基分别计算新的质量分数

// 4. 将计算后的质量分数赋值给read

#include <header.h>  // in htslib
#include <htslib/sam.h>
#include <htslib/thread_pool.h>

#include "aux_arg.h"
#include "common_data.h"
#include "util/debug.h"
#include "util/profiling.h"
#include "recal_utils.h"
#include "recal_funcs.h"
#include "read_utils.h"

using std::vector;

namespace nsgv {
// 全局变量 for apply bqsr
samFile* gOutBamFp;        // 输出文件, sam或者bam格式
sam_hdr_t* gOutBamHeader;  // 输出文件的header
RecalTables gRecalTables;  // 保留一个全局的recalibrate tables就行了
vector<uint8_t> gQuantizedQuals; // 读取quantized info table信息得到的，第三列数据
StableArray<bam1_t*> gRecalBams[2];  // 保存已经校正过质量分数的bam数据，双buffer
};  // namespace nsgv

// 串行apply bqsr
int SerialApplyBQSR(AuxVar &aux) {
    BamBufType inBamBuf(nsgv::gBqsrArg.DUPLEX_IO);
    inBamBuf.Init(nsgv::gInBamFp, nsgv::gInBamHeader, nsgv::gBqsrArg.MAX_MEM, RecalFuncs::applyBqsrReadFilterOut);
    int64_t readNumSum = 0;
    int round = 0;

    PerReadCovariateMatrix& readCovariates = aux.readCovariates;
    // 一. 读取并解析recalibrate tables
    auto& recalTables = *aux.bqsrTable;

    // 全局的校正后的bam数组
    auto& recalBams = nsgv::gRecalBams[0];

    auto& sd = aux.sd;

    while (true) {
        ++round;
        // 一. 读取bam数据
        size_t readNum = 0;
        PROF_START(GP_read);
        if (inBamBuf.ReadStat() >= 0)
            readNum = inBamBuf.ReadBam();
        PROF_GP_END(GP_read);
        if (readNum < 1) {
            break;
        }
        auto bams = inBamBuf.GetBamArr();
        spdlog::info("{} reads processed in {} round", readNum, round);

        if (recalBams.size() < bams.size()) {
            int start = recalBams.size();
            recalBams.resize(bams.size());
            for (int i = start; i < recalBams.size(); ++i) {
                recalBams[i] = bam_init1();
            }
        }

        // 二. 遍历每个bam（read）记录，进行处理
        for (int i = 0; i < bams.size(); ++i) {
            if (bam_copy1(recalBams[i], bams[i]->b) == NULL) {
                spdlog::error("Copy bam error");
                exit(1);
            }
            BamWrap* bw = bams[i];
            bw->b = recalBams[i]; // 注意这里的赋值，然后就可以对b进行更改了
            sd.init();
            sd.parseForApplyBQSR(bw);
            sd.rid = i + aux.processedReads;

            // 1. 是否使用original quality来代替当前的quality
            if (nsgv::gBqsrArg.useOriginalBaseQualities)
                ReadUtils::resetOriginalBaseQualities(bw->b);

            // 2. 是否将当前的quality保存在tag OQ中
            if (nsgv::gBqsrArg.emitOriginalQuals)
                ReadUtils::setOriginalBaseQualsIfNoOQ(bw->b);

            // 3. 计算read的协变量covs
            PROF_START(GP_covariate);
            CovariateUtils::ComputeCovariates(sd, aux.header, readCovariates, nsgv::gBqsrArg.computeIndelBQSRTables, 0);
            PROF_GP_END(GP_covariate);

            // clear indel qualities
            ReadUtils::removeAttribute(bw->b, "BI");
            ReadUtils::removeAttribute(bw->b, "BD");

            // 4. 检查read的readGroup tag是否包含在bqsr table里
            const char* readGroupId = ReadUtils::getReadGroupId(bw->b);
            auto& covaritesForRead = readCovariates[EventType::BASE_SUBSTITUTION.index];
            uint8_t* recalibratedQuals = bam_get_qual(bw->b);
            auto& preUpdateQuals = sd.base_quals;
            int rgKey = -1;
            if (ReadGroupCovariate::RgToId.find(std::string(readGroupId)) != ReadGroupCovariate::RgToId.end())
                rgKey = ReadGroupCovariate::RgToId[std::string(readGroupId)];
            if (rgKey == -1) {
                if (nsgv::gBqsrArg.allowMissingReadGroups) {
                    // Given the way the recalibration code is implemented below, we cannot recalibrate a read with a
                    // read group that's not in the recal table.
                    for (int i = 0; i < sd.read_len; i++) {
                        //recalibratedQuals[i] = staticQuantizedMapping != null ? staticQuantizedMapping[preUpdateQuals[i]] : quantizedQuals.get(preUpdateQuals[i]);
                        recalibratedQuals[i] = nsgv::gQuantizedQuals[preUpdateQuals[i]];
                    }
                } else {
                    spdlog::error(
                        "Read group {} not found in the recalibration table. Use \"--allow-missing-read-group\" command line argument to ignore this "
                        "error.",
                        readGroupId);
                    exit(1);
                }
            }

            // 5. 根据recal tables数据对read的每个碱基分别计算新的质量分数
            auto& readGroupDatum = recalTables.readGroupTable(EventType::BASE_SUBSTITUTION.index, rgKey);
            // Note: this loop is under very heavy use in applyBQSR. Keep it slim.
            for (int offset = 0; offset < sd.read_len; offset++) {  // recalibrate all bases in the read
                // only recalibrate usable qualities (default: >= 6) (the original quality will come from the instrument -- reported quality)
                if (recalibratedQuals[offset] < nsgv::gBqsrArg.PRESERVE_QSCORES_LESS_THAN) {
                    continue;
                }
                auto& covs = readCovariates[EventType::BASE_SUBSTITUTION.index][offset];
                // 根据read的协变量数据获取对应的bqsr数据
                auto& qualityScoreDatum = recalTables.qualityScoreTable(EventType::BASE_SUBSTITUTION.index, rgKey, covs.baseQuality);
                auto& contextDatum = recalTables.contextTable(EventType::BASE_SUBSTITUTION.index, rgKey, covs.baseQuality, covs.context);
                auto& cycleDatum = recalTables.cycleTable(EventType::BASE_SUBSTITUTION.index, rgKey, covs.baseQuality, covs.cycle);
                // 计算校正后的质量分数
                double priorQualityScore =
                    nsgv::gBqsrArg.globalQScorePrior > 0.0 ? nsgv::gBqsrArg.globalQScorePrior : readGroupDatum.getReportedQuality();
                double rawRecalibratedQualityScore =
                    RecalFuncs::hierarchicalBayesianQualityEstimate(priorQualityScore, readGroupDatum, qualityScoreDatum, contextDatum, cycleDatum);
                uint8_t qualIdx = RecalFuncs::getBoundedIntegerQual(rawRecalibratedQualityScore);
                uint8_t quantizedQualityScore = qualIdx;  // nsgv::gQuantizedQuals.at(qualIdx);
                // TODO: as written the code quantizes *twice* if the static binning is enabled (first time to the dynamic bin). It should be
                // quantized once.
                // recalibratedQuals[offset] = staticQuantizedMapping == null ? quantizedQualityScore : staticQuantizedMapping[quantizedQualityScore];
                recalibratedQuals[offset] = quantizedQualityScore;
            }

            if (sam_write1(nsgv::gOutBamFp, nsgv::gOutBamHeader, bw->b) < 0) {
                spdlog::error("failed writing sam record to \"{}\"", nsgv::gBqsrArg.OUTPUT_FILE.c_str());
                sam_close(nsgv::gInBamFp);
                sam_close(nsgv::gOutBamFp);
                exit(1);
            }
            //break;
        }
        // break;

        readNumSum += readNum;
        AuxVar::processedReads += readNum;
        inBamBuf.ClearAll();  // 清空bam buf
    }

    spdlog::info("read count: {}", readNumSum);

    return 0;
}

// 并行 apply bqsr
int ParallelApplyBQSR(vector<AuxVar> &auxArr) {

    return 0;
}

// 在进行数据处理之前，初始化一些全局数据
static void globalInit() {
    open_debug_files();
    /* bam */
    nsgv::gInBamFp = sam_open_format(nsgv::gBqsrArg.INPUT_FILE.c_str(), "r", nullptr);
    if (!nsgv::gInBamFp) {
        spdlog::error("[{}] load sam/bam file failed.\n", __func__);
        exit(1);
    }
    hts_set_opt(nsgv::gInBamFp, HTS_OPT_BLOCK_SIZE, BAM_BLOCK_SIZE);
    nsgv::gInBamHeader = sam_hdr_read(nsgv::gInBamFp);  // header

    /* 并行读取bam数据  */
    htsThreadPool htsPoolRead = {NULL, 0};  //
    int readThreadNum = min(nsgv::gBqsrArg.NUM_THREADS, BAM_READ_MAX_THREAD);
    htsPoolRead.pool = hts_tpool_init(readThreadNum);
    if (!htsPoolRead.pool) {
        spdlog::error("[{}] failed to set up thread pool", __LINE__);
        sam_close(nsgv::gInBamFp);
        exit(1);
    }
    hts_set_opt(nsgv::gInBamFp, HTS_OPT_THREAD_POOL, &htsPoolRead);

    if (!nsgv::gInBamHeader->hrecs) {
        if (sam_hdr_fill_hrecs(nsgv::gInBamHeader) != 0) {
            spdlog::error("[{}] failed to read sam header", __LINE__);
            sam_close(nsgv::gInBamFp);
            exit(1);
        }
    }
    /* 并行写入bam文件 */
    char modeout[12] = "wb";
    sam_open_mode(modeout + 1, nsgv::gBqsrArg.OUTPUT_FILE.c_str(), NULL);
    nsgv::gOutBamFp = sam_open(nsgv::gBqsrArg.OUTPUT_FILE.c_str(), modeout);
    if (!nsgv::gOutBamFp) {
        spdlog::error("[{}] create output sam/bam file failed.\n", __func__);
        exit(1);
    }
    nsgv::gOutBamHeader = sam_hdr_dup(nsgv::gInBamHeader);
    // 修改输出文件的header
    sam_hdr_add_line(nsgv::gOutBamHeader, "PG", "ID", PROGRAM_NAME, "VN", FASTBQSR_VERSION, "CL", nsgv::gBqsrArg.CLI_STR.c_str(), NULL);
    // 用不同的线程数量处理输出文件
    htsThreadPool htsPoolWrite = {NULL, 0};  // 读写用不同的线程池
    int writeThreadNum = min(nsgv::gBqsrArg.NUM_THREADS, BAM_WRITE_MAX_THREAD);
    htsPoolWrite.pool = hts_tpool_init(writeThreadNum);
    if (!htsPoolWrite.pool) {
        spdlog::error("[{}] failed to set up thread pool", __LINE__);
        sam_close(nsgv::gInBamFp);
        exit(1);
    }
    hts_set_opt(nsgv::gOutBamFp, HTS_OPT_BLOCK_SIZE, BAM_BLOCK_SIZE);
    hts_set_opt(nsgv::gOutBamFp, HTS_OPT_THREAD_POOL, &htsPoolWrite);

    if (sam_hdr_write(nsgv::gOutBamFp, nsgv::gOutBamHeader) != 0) {
        spdlog::error("failed writing header to \"{}\"", nsgv::gBqsrArg.OUTPUT_FILE);
        sam_close(nsgv::gOutBamFp);
        sam_close(nsgv::gInBamFp);
        exit(1);
    }

    // 输出index文件
    nsgv::gBqsrArg.INDEX_FILE = nsgv::gBqsrArg.OUTPUT_FILE + ".bai";  // min_shift = 0 是bai格式
    if ("sam" == Utils::getFileExtension(nsgv::gBqsrArg.OUTPUT_FILE) || !nsgv::gBqsrArg.CREATE_INDEX) {
        nsgv::gBqsrArg.INDEX_FILE = "";
    }
    if (!nsgv::gBqsrArg.INDEX_FILE.empty()) {
        int index_min_shift = 0;
        if (nsgv::gBqsrArg.INDEX_FORMAT == nsbqsr::IndexFormat::CSI) {
            nsgv::gBqsrArg.INDEX_FILE = nsgv::gBqsrArg.OUTPUT_FILE + ".csi";
            index_min_shift = 14;
        }
        if (sam_idx_init(nsgv::gOutBamFp, nsgv::gOutBamHeader, 0 /*csi 14*/, nsgv::gBqsrArg.INDEX_FILE.c_str()) < 0) {
            spdlog::error("failed to open index \"{}\" for writing", nsgv::gBqsrArg.INDEX_FILE);
            sam_close(nsgv::gOutBamFp);
            sam_close(nsgv::gInBamFp);
            exit(1);
        }
    }

    // 1. 协变量数据相关初始化
    ContextCovariate::InitContextCovariate(nsgv::gBqsrArg);
    CycleCovariate::InitCycleCovariate(nsgv::gBqsrArg);

    // 注意初始化顺序，这个必须在协变量初始化之后，因为需要用到MaximumKeyValue
    // nsgv::gRecalTables.init(nsgv::gInBamHeader->hrecs->nrg);

    // 初始化AuxVar
    nsgv::gAuxVars.resize(nsgv::gBqsrArg.NUM_THREADS);
    for (int i = 0; i < nsgv::gBqsrArg.NUM_THREADS; ++i) {
        nsgv::gAuxVars[i].header = nsgv::gInBamHeader;
        nsgv::gAuxVars[i].faidx = fai_load(nsgv::gBqsrArg.REFERENCE_FILE.c_str());
        if (nsgv::gAuxVars[i].faidx == 0)
            error("[%s] fail to load the fasta index.\n", __func__);
        // 注意初始化顺序，这个必须在协变量初始化之后，因为需要用到MaximumKeyValue
        nsgv::gAuxVars[i].bqsrTable = &nsgv::gRecalTables;
        CovariateUtils::InitPerReadCovMat(nsgv::gAuxVars[i].readCovariates);
    }

    // 0. 初始化一些全局数据
    RecalDatum::StaticInit();
    QualityUtils::StaticInit();
    MathUtils::StaticInit();
    BaseUtils::StaticInit();

    // 初始化需要计算的event types
    RecalUtils::initEventTypes(nsgv::gBqsrArg.computeIndelBQSRTables);

    // 2. 读取bam的read group
    // if (nsgv::gInBamHeader->hrecs->nrg == 0) {
    //     spdlog::error("No RG tag found in the header!");
    //     exit(1);
    // }

    /*
    // 应该是从bqsr table里读取read group信息
    for (int i = 0; i < nsgv::gInBamHeader->hrecs->nrg; ++i) {
        // spdlog::info("rg: {}", nsgv::gInBamHeader->hrecs->rg[i].name);
        ReadGroupCovariate::RgToId[nsgv::gInBamHeader->hrecs->rg[i].name] = i;
        ReadGroupCovariate::IdToRg[i] = nsgv::gInBamHeader->hrecs->rg[i].name;
    }
    */

    // 读取并解析recalibrate tables
    RecalUtils::readRecalTables(nsgv::gBqsrArg.BQSR_FILE, nsgv::gBqsrArg, nsgv::gQuantizedQuals, nsgv::gRecalTables);
}

// 全局资源释放
static void globalDestroy() { 
    close_debug_files();

    if (!nsgv::gBqsrArg.INDEX_FILE.empty() && sam_idx_save(nsgv::gOutBamFp) < 0) {
        spdlog::error("writing index failed");
        sam_close(nsgv::gOutBamFp);
        sam_close(nsgv::gInBamFp);
        exit(1);
    }

    /* 关闭文件，收尾清理 */
    sam_close(nsgv::gOutBamFp);
    sam_close(nsgv::gInBamFp);
}

// entrance of BQSR phase-1
int ApplyBQSR() {
    int ret = 0;

    PROF_START(GP_whole_process);
    globalInit();
//    if (nsgv::gBqsrArg.NUM_THREADS == 1)
        ret = SerialApplyBQSR(nsgv::gAuxVars[0]);  // 串行处理数据，生成recal bams
//    else
//        ret = ParallelApplyBQSR(nsgv::gAuxVars);  // 并行处理数据，生成recal bams
    globalDestroy();
    PROF_GP_END(GP_whole_process);

    return ret;
}