process BIOBAMBAM_BAMMERGE {
    tag "$meta.id"
    label 'process_low'

    conda (params.enable_conda ? "bioconda::biobambam=2.0.183" : null)
    container "${ workflow.containerEngine == 'singularity' && !task.ext.singularity_pull_docker_container ?
        'https://depot.galaxyproject.org/singularity/biobambam:2.0.183--h9f5acd7_1':
        'quay.io/biocontainers/biobambam:2.0.183--h9f5acd7_1' }"

    input:
    tuple val(meta), path(bam)

    output:
    tuple val(meta), path("${prefix}.bam")    ,emit: bam
    tuple val(meta), path("*.bam.bai")        ,optional:true, emit: bam_index
    path "versions.yml"                       ,emit: versions

    when:
    task.ext.when == null || task.ext.when

    script:
    def args = task.ext.args ?: ''
    prefix = task.ext.prefix ?: "${meta.id}"
    def input_string = bam.join(" I=")

    """
    bammerge \\
        I=${input_string} \\
        $args \\
        > ${prefix}.bam

    cat <<-END_VERSIONS > versions.yml
    "${task.process}":
        bammerge: \$(echo \$(bammerge --version 2>&1) | sed 's/^This is biobambam2 version //; s/..biobambam2 is .*\$//' )
    END_VERSIONS
    """
}