__author__ = "Julian de Ruiter"
__copyright__ = "Copyright 2017, Julian de Ruiter"
__email__ = "julianderuiter@gmail.com"
__license__ = "MIT"


from os import path
import re
from tempfile import TemporaryDirectory

from snakemake.shell import shell

log = snakemake.log_fmt_shell(stdout=True, stderr=True)


def basename_without_ext(file_path):
    """Returns basename of file path, without the file extension."""

    base = path.basename(file_path)
    # Remove file extension(s) (similar to the internal fastqc approach)
    base = re.sub("\\.gz$", "", base)
    base = re.sub("\\.bz2$", "", base)
    base = re.sub("\\.txt$", "", base)
    base = re.sub("\\.fastq$", "", base)
    base = re.sub("\\.fq$", "", base)
    base = re.sub("\\.sam$", "", base)
    base = re.sub("\\.bam$", "", base)

    return base


# Run fastqc, since there can be race conditions if multiple jobs
# use the same fastqc dir, we create a temp dir.
with TemporaryDirectory() as tempdir:
    shell(
        "fastqc {snakemake.params} -t {snakemake.threads} "
        "--outdir {tempdir:q} {snakemake.input[0]:q}"
        " {log}"
    )

    # Move outputs into proper position.
    output_base = basename_without_ext(snakemake.input[0])
    html_path = path.join(tempdir, output_base + "_fastqc.html")
    zip_path = path.join(tempdir, output_base + "_fastqc.zip")

    if snakemake.output.html != html_path:
        shell("mv {html_path:q} {snakemake.output.html:q}")

    if snakemake.output.zip != zip_path:
        shell("mv {zip_path:q} {snakemake.output.zip:q}")

myargs <- commandArgs(trailingOnly=TRUE)
bamfile <- myargs[1]
species <- myargs[2]

print("loading packages (ATACseqQC, ggplot, etc)...")
suppressPackageStartupMessages(library(ggplot2, quietly=TRUE))
suppressPackageStartupMessages(library(Rsamtools, quietly=TRUE))
suppressPackageStartupMessages(library(ATACseqQC, quietly=TRUE))
suppressPackageStartupMessages(library(ChIPpeakAnno, quietly=TRUE))
suppressPackageStartupMessages(library("GenomicAlignments", quietly=TRUE))

if (species == "mm") {
  suppressPackageStartupMessages(library(TxDb.Mmusculus.UCSC.mm10.knownGene, quietly=TRUE))
  suppressPackageStartupMessages(library(BSgenome.Mmusculus.UCSC.mm10, quietly=TRUE))
  txdb <- TxDb.Mmusculus.UCSC.mm10.knownGene
  bsgenome <- BSgenome.Mmusculus.UCSC.mm10
  genome <- Mmusculus
  print("species is 'mm' using mm10 for analysis")
  ### Note: Everything below is deprecated until I can figure out a way to port a 
  ### static/local package with snakemake
  # Note: phastCons60way was manually curated from GenomicAlignments, built, and installed as an R package
  # score was obtained according to: https://support.bioconductor.org/p/96226/
  # package was built and installed according to: https://www.bioconductor.org/packages/devel/bioc/vignettes/GenomicScores/inst/doc/GenomicScores.html
  # (section 5.1: Building an annotation package from a GScores object)
  #suppressWarnings(suppressPackageStartupMessages(library(GenomicScores, lib.loc="/users/dia6sx/snakeATAC/scripts/", quietly=TRUE)))
  #suppressWarnings(suppressPackageStartupMessages(library(phastCons60way.UCSC.mm10, lib.loc="/users/dia6sx/snakeATAC/scripts/", quietly=TRUE)))
} else if (species == "hs") {
  suppressPackageStartupMessages(library(TxDb.Hsapiens.UCSC.hg38.knownGene, quietly=TRUE))
  suppressPackageStartupMessages(library(BSgenome.Hsapiens.UCSC.hg38, quietly=TRUE))
  txdb <- TxDb.Hsapiens.UCSC.hg38.knownGene
  bsgenome <- BSgenome.Hsapiens.UCSC.hg38
  genome <- Hsapiens
  print("species is 'hs' using hg38 for analysis")
} else {
  print(paste("params ERROR: ATACseqQC is not configured to use species =", species))
  print("exiting...")
  quit(status=1)
}

doATACseqQC <- function(bamfile, txdb, bsgenome, genome) {
    # Fragment size distribution
    print(paste("generating output for ",strsplit(basename(bamfile),split='\\.')[[1]][1],"...",sep=""))
    print("calculating Fragment size distribution...")
    bamfile.labels <- gsub(".bam", "", basename(bamfile))
    loc_to_save_figures <- paste(dirname(dirname(bamfile)),"/qc/ATACseqQC",sep="")
    if (file.exists(loc_to_save_figures)) {
        print("Warning: old figures will be overwritten")
    } else {
        dir.create(loc_to_save_figures)
    }
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_fragment_size_distribution.png",sep="")
    png(png_file)
    fragSizeDist(bamfile, bamfile.labels)
    dev.off()

    # Adjust the read start sites
    print("adjusting read start sites...")
    ## bamfile tags to be read in
    possibleTag <- list("integer"=c("AM", "AS", "CM", "CP", "FI", "H0", "H1", "H2", 
                                    "HI", "IH", "MQ", "NH", "NM", "OP", "PQ", "SM",
                                    "TC", "UQ"), 
                    "character"=c("BC", "BQ", "BZ", "CB", "CC", "CO", "CQ", "CR",
                                "CS", "CT", "CY", "E2", "FS", "LB", "MC", "MD",
                                "MI", "OA", "OC", "OQ", "OX", "PG", "PT", "PU",
                                "Q2", "QT", "QX", "R2", "RG", "RX", "SA", "TS",
                                "U2"))
    bamTop100 <- scanBam(BamFile(bamfile, yieldSize = 100),
                     param = ScanBamParam(tag=unlist(possibleTag)))[[1]]$tag
    tags <- names(bamTop100)[lengths(bamTop100)>0]
    ## files will be output into outPath
    ## shift the coordinates of 5'ends of alignments in the bam file
    outPath <- paste(dirname(dirname(bamfile)),"/alignments_shifted", sep="")
    seqinformation <- seqinfo(txdb)
    gal <- readBamFile(bamfile, tag=tags, asMates=TRUE, bigFile=TRUE)
    shiftedBamfile <- file.path(outPath, paste(bamfile.labels,"_shifted.bam",sep=""))
    # check if shifted Bam file exists from previous run
    if (file.exists(shiftedBamfile)) {
        print("Shifted Bamfile found.")
        print("Loading in...")
        gal <- readBamFile(shiftedBamfile, tag=tags, asMates=TRUE, bigFile=TRUE)
        ## This step is mostly for formating so splitBam can
        ## take in bamfile. Implementing shift of 0 bp on positive strand
        ## and 0 bp on negative strand because shifted Bamfile should
        ## already have these shifts
        gal1 <- shiftGAlignmentsList(gal, positive = 0L, negative = 0L)
    } else {
        # shifted bam file does not exist check if
        # old shifted alignments directory exists
        # if so remove and create new one
        if (file.exists(outPath)){
            unlink(outPath,recursive=TRUE)
        }
        dir.create(outPath)
        print("*** creating shifted bam file ***")
        gal1 <- shiftGAlignmentsList(gal, outbam=shiftedBamfile)
    }

    # Promoter/Transcript body (PT) score
    print("calculating Promoter/Transcript body (PT) score...")
    txs <- transcripts(txdb)
    pt <- PTscore(gal1, txs)
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_ptscore.png",sep="")
    png(png_file)
    plot(pt$log2meanCoverage, pt$PT_score, 
        xlab="log2 mean coverage",
        ylab="Promoter vs Transcript",
        main=paste(bamfile.labels,"PT score"))
    dev.off()

    # Nucleosome Free Regions (NFR) score
    print("calculating Nucleosome Free Regions (NFR) score")
    nfr <- NFRscore(gal1, txs)
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_nfrscore.png",sep="")
    png(png_file)
    plot(nfr$log2meanCoverage, nfr$NFR_score, 
        xlab="log2 mean coverage",
        ylab="Nucleosome Free Regions score",
        main=paste(bamfile.labels,"\n","NFRscore for 200bp flanking TSSs",sep=""),
        xlim=c(-10, 0), ylim=c(-5, 5))
    dev.off()

    # Transcription Start Site (TSS) Enrichment Score
    print("calculating Transcription Start Site (TSS) Enrichment score")
    tsse <- TSSEscore(gal1, txs)
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_tss_enrichment_score.png",sep="")
    png(png_file)
    plot(100*(-9:10-.5), tsse$values, type="b", 
        xlab="distance to TSS",
        ylab="aggregate TSS score",
        main=paste(bamfile.labels,"\n","TSS Enrichment score",sep=""))
    dev.off()

    # Split reads, Heatmap and coverage curve for nucleosome positions
    print("splitting reads by fragment length...")
    genome <- genome
    outPath <- paste(dirname(dirname(bamfile)),"/alignments_split", sep="")
    TSS <- promoters(txs, upstream=0, downstream=1)
    TSS <- unique(TSS)
    ## estimate the library size for normalization
    librarySize <- estLibSize(bamfile)
    ## calculate the signals around TSSs.
    NTILE <- 101
    dws <- ups <- 1010
    splitBamfiles <- paste(outPath,"/",c("NucleosomeFree", 
                                             "mononucleosome",
                                             "dinucleosome",
                                             "trinucleosome"),".bam",sep="")
    # check if split Bam files exists from previous run
    if (all(file.exists(splitBamfiles))) {
        print("*** split bam files found! ***")
        print("Loading in...")
        sigs <- enrichedFragments(bamfiles=splitBamfiles,
                                    index=splitBamfiles, 
                                    TSS=TSS,
                                    librarySize=librarySize,
                                    TSS.filter=0.5,
                                    n.tile = NTILE,
                                    upstream = ups,
                                    downstream = dws)
    } else {
        # split bam files do not exist check if
        # old split alignments directory exists
        # if so remove and create new one
        if (file.exists(outPath)){
            unlink(outPath,recursive=TRUE)
        }
        print("*** creating split bam files ***")
        dir.create(outPath)
        ## split the reads into NucleosomeFree, mononucleosome, 
        ## dinucleosome and trinucleosome.
        ## and save the binned alignments into bam files.
        objs <- splitGAlignmentsByCut(gal1, txs=txs, genome=genome, outPath = outPath)
        #objs <- splitBam(bamfile, tags=tags, outPath=outPath,
            #        txs=txs, genome=genome,
            #       conservation=phastCons60way.UCSC.mm10,
            #      seqlev=paste0("chr", c(1:19, "X", "Y")))
        sigs <- enrichedFragments(gal=objs[c("NucleosomeFree", 
                                        "mononucleosome",
                                        "dinucleosome",
                                        "trinucleosome")], 
                                    TSS=TSS,
                                    librarySize=librarySize,
                                    TSS.filter=0.5,
                                    n.tile = NTILE,
                                    upstream = ups,
                                    downstream = dws)
    }
    ## log2 transformed signals
    sigs.log2 <- lapply(sigs, function(.ele) log2(.ele+1))
    ## plot heatmap
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_nucleosome_pos_heatmap.png",sep="")
    png(png_file)
    featureAlignedHeatmap(sigs.log2, reCenterPeaks(TSS, width=ups+dws),
                        zeroAt=.5, n.tile=NTILE)
    dev.off()
    ## get signals normalized for nucleosome-free and nucleosome-bound regions.
    out <- featureAlignedDistribution(sigs, 
                                    reCenterPeaks(TSS, width=ups+dws),
                                    zeroAt=.5, n.tile=NTILE, type="l", 
                                    ylab="Averaged coverage")
    ## rescale the nucleosome-free and nucleosome signals to 0~1
    range01 <- function(x){(x-min(x))/(max(x)-min(x))}
    out <- apply(out, 2, range01)
    png_file <- paste(loc_to_save_figures,"/",bamfile.labels,"_TSS_signal_distribution.png",sep="")
    png(png_file)
    matplot(out, type="l", xaxt="n", 
            xlab="Position (bp)", 
            ylab="Fraction of signal",
            main=paste(bamfile.labels,"\n","TSS signal distribution",sep=""))
    axis(1, at=seq(0, 100, by=10)+1, 
        labels=c("-1K", seq(-800, 800, by=200), "1K"), las=2)
    abline(v=seq(0, 100, by=10)+1, lty=2, col="gray")
    dev.off()

    print("QC Finished.")
    print("Generated QC figures can be found in qc folder under ATACseQC")
    print(paste("*** removing temp files in",outPath,"***"))
    unlink(outPath,recursive=TRUE)
    outPath <- paste(dirname(dirname(bamfile)),"/alignments_shifted", sep="")
    print(paste("*** removing temp files in",outPath,"***"))
    unlink(outPath,recursive=TRUE)
}

doATACseqQC(bamfile, txdb, bsgenome, genome)

read_counts=$(gunzip -c ${1} | wc -l)

# Sort and merge input peaks. Then intersect with list of tags
# Bedtools docs for -u: Write original A entry (tag) once if any overlaps found in B (peaks). In other words, just report the fact at least one overlap was found in B
reads_in_peaks=$(bedtools sort -i ${2} | bedtools merge -i - | bedtools intersect -u -a ${1} -b - | wc -l)

echo ${reads_in_peaks} > ${3}
echo ${read_counts} >> ${3}

echo $(bc -l <<< "${reads_in_peaks}/${read_counts}") >> ${3}

mapped_reads=$(samtools view -c -F 260 ${1})
reads_factor=$(bc -l <<< "1/${mapped_reads}")
rpm_factor=$(bc -l <<< "${reads_factor} * ${2}")

bedtools genomecov -i ${3} -g ${4} -bg -scale ${rpm_factor} | LC_COLLATE=C sort -k1,1 -k2,2n > ${5}

bedGraphToBigWig ${5} ${4} ${6}

shell:
    """
    bowtie2 {params.bowtie} -p {threads} -x {config[idx_bt2]} -1 {input[0]} -2 {input[1]} -S {output} 2> {log}
    """

shell:
    """
    samtools view -@ {threads} -b -u -q 30 {input} | \
    samtools sort -@ {threads} -n -o {output} -
    """

shell:
    """
    macs2 callpeak -t {input} --name {params.NAME} -g {params.species} --outdir {params.PEAK_DIR} --nomodel --shift -{params.shift_size} --extsize {params.ext_size} --keep-dup=all -q 0.{params.qvalue}
    """

shell:
    """
    trim_galore -q 30 -paired -j 4 -o {params.TRIM_DIR} {input.fq1} {input.fq2} 2> {log}
    """

shell:
    """
    # Select Parameter Description

    # runThreadN: Number of threads to use
    # readFilesIn: Fastq files
    # outFileNamePrefix: Prefix of the outputDIR and the name to use
    # outSAMtype: Output the file as a BAM file that is sorted
    # outSAMunmapped: Output unmapped reads in the SAM file with special flag
    # outSAMattributes: Standard SAM attributes
    # alignIntronMax: Allow only 1 max intron. This is specific to ATAC-seq
    # STAR was designed for RNA transcripts so we want to ignore some parameters
    # alignMatesGapMax: Allow a maximum of 2000 bp gap.
    # alignEndsType: This aligns the full read and considers the whole read in score calculation.
    # outMultimapperOrder: Output multimapped reads in random order
    # outFilterMultimapNmax: Max 1000 multimapped reads
    # outSAMmultNmax: 1
    # outFilterMismatchNoverLmax: .1 mismatch
    # outFilterMatchNmin: 20
    # alignSJDBoverhangMin: 999
    # alignEndsProtrude: 10 ConcordantPair 
    # outFilterScoreMinOverLread: 0.66
    # outFilterMatchNminOverLread: 0.66
    # readFilesCommand: zcat

    echo "Align Files with STAR: In Progress"

    STAR --genomeDir {params.STAR_INDEX} \
    --runThreadN {params.THREADS} \
    --readFilesIn {input[0]} {input[1]} \
    --outFileNamePrefix {params.Prefix} \
    --outSAMtype BAM SortedByCoordinate \
    --outSAMattributes Standard \
    --alignIntronMax 1 \
    --alignMatesGapMax 2000 \
    --alignEndsType EndToEnd \
    --outMultimapperOrder Random \
    --outFilterMultimapNmax 999 \
    --outSAMmultNmax 1 \
    --outFilterMismatchNoverLmax 0.1 \
    --outFilterMatchNmin 20 \
    --alignSJDBoverhangMin 999 \
    --alignEndsProtrude 10 ConcordantPair  \
    --outFilterScoreMinOverLread 0.66 \
    --outFilterMatchNminOverLread 0.66 \
    --readFilesCommand zcat
    """