Shortread subworkflow

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### `Fixed`
 
+- [#716](https://github.com/nf-core/mag/pull/692) - Make short read processing a subworkflow (added by @muabnezor)
 - [#708](https://github.com/nf-core/mag/pull/708) - Fixed channel passed as GUNC input (added by @dialvarezs)
 
 ### `Dependencies`

subworkflows/local/shortread_preprocessing.nf

@@ -0,0 +1,178 @@
+/*
+ * SHORTREAD_PREPROCESSING: Preprocessing and QC for short reads
+ */
+
+include { FASTQC as FASTQC_RAW                                } from '../../modules/nf-core/fastqc/main'
+include { FASTQC as FASTQC_TRIMMED                            } from '../../modules/nf-core/fastqc/main'
+include { FASTP                                               } from '../../modules/nf-core/fastp/main'
+include { ADAPTERREMOVAL as ADAPTERREMOVAL_PE                 } from '../../modules/nf-core/adapterremoval/main'
+include { ADAPTERREMOVAL as ADAPTERREMOVAL_SE                 } from '../../modules/nf-core/adapterremoval/main'
+include { BOWTIE2_REMOVAL_BUILD as BOWTIE2_HOST_REMOVAL_BUILD } from '../../modules/local/bowtie2_removal_build'
+include { BOWTIE2_REMOVAL_ALIGN as BOWTIE2_HOST_REMOVAL_ALIGN } from '../../modules/local/bowtie2_removal_align'
+include { BOWTIE2_REMOVAL_BUILD as BOWTIE2_PHIX_REMOVAL_BUILD } from '../../modules/local/bowtie2_removal_build'
+include { BOWTIE2_REMOVAL_ALIGN as BOWTIE2_PHIX_REMOVAL_ALIGN } from '../../modules/local/bowtie2_removal_align'
+include { CAT_FASTQ                                           } from '../../modules/nf-core/cat/fastq/main'
+include { SEQTK_MERGEPE                                       } from '../../modules/nf-core/seqtk/mergepe/main'
+include { BBMAP_BBNORM                                        } from '../../modules/nf-core/bbmap/bbnorm/main'
+
+workflow SHORTREAD_PREPROCESSING {
+    take:
+    ch_raw_short_reads        // [ [meta] , fastq1, fastq2] (mandatory)
+    ch_host_fasta             // [fasta] (optional)
+    ch_phix_db_file           // [fasta] (optional)
+    ch_metaeuk_db             // [fasta] (optional)
+
+    main:
+    ch_versions = Channel.empty()
+    ch_multiqc_files = Channel.empty()
+
+    FASTQC_RAW(
+        ch_raw_short_reads
+    )
+    ch_versions = ch_versions.mix(FASTQC_RAW.out.versions.first())
+    ch_multiqc_files = ch_multiqc_files.mix(FASTQC_RAW.out.zip)
+
+    if (!params.skip_clipping) {
+        if (params.clip_tool == 'fastp') {
+            FASTP(
+                ch_raw_short_reads,
+                [],
+                params.fastp_save_trimmed_fail,
+                []
+            )
+            ch_short_reads_prepped = FASTP.out.reads
+            ch_versions = ch_versions.mix(FASTP.out.versions.first())
+            ch_multiqc_files = ch_multiqc_files.mix(FASTP.out.json)
+
+        }
+        else if (params.clip_tool == 'adapterremoval') {
+
+            // due to strange output file scheme in AR2, have to manually separate
+            // SE/PE to allow correct pulling of reads after.
+            ch_adapterremoval_in = ch_raw_short_reads.branch {
+                single: it[0]['single_end']
+                paired: !it[0]['single_end']
+            }
+
+            ADAPTERREMOVAL_PE(ch_adapterremoval_in.paired, [])
+            ADAPTERREMOVAL_SE(ch_adapterremoval_in.single, [])
+
+            ch_short_reads_prepped = Channel.empty()
+            ch_short_reads_prepped = ch_short_reads_prepped.mix(ADAPTERREMOVAL_SE.out.singles_truncated, ADAPTERREMOVAL_PE.out.paired_truncated)
+
+            ch_versions = ch_versions.mix(ADAPTERREMOVAL_PE.out.versions.first(), ADAPTERREMOVAL_SE.out.versions.first())
+            ch_multiqc_files = ch_multiqc_files.mix(ADAPTERREMOVAL_PE.out.settings)
+            ch_multiqc_files = ch_multiqc_files.mix(ADAPTERREMOVAL_SE.out.settings)
+        }
+    }
+    else {
+        ch_short_reads_prepped = ch_raw_short_reads
+    }
+
+    if (params.host_fasta) {
+        if (params.host_fasta_bowtie2index) {
+            ch_host_bowtie2index = file(params.host_fasta_bowtie2index, checkIfExists: true)
+        }
+        else {
+            BOWTIE2_HOST_REMOVAL_BUILD(
+                ch_host_fasta
+            )
+            ch_host_bowtie2index = BOWTIE2_HOST_REMOVAL_BUILD.out.index
+        }
+    }
+
+    if (params.host_fasta || params.host_genome) {
+        BOWTIE2_HOST_REMOVAL_ALIGN(
+            ch_short_reads_prepped,
+            ch_host_bowtie2index
+        )
+        ch_short_reads_hostremoved = BOWTIE2_HOST_REMOVAL_ALIGN.out.reads
+        ch_versions = ch_versions.mix(BOWTIE2_HOST_REMOVAL_ALIGN.out.versions.first())
+        ch_multiqc_files = ch_multiqc_files.mix(BOWTIE2_HOST_REMOVAL_ALIGN.out.log)
+    }
+    else {
+        ch_short_reads_hostremoved = ch_short_reads_prepped
+    }
+
+    if (!params.keep_phix) {
+        BOWTIE2_PHIX_REMOVAL_BUILD(
+            ch_phix_db_file
+        )
+        BOWTIE2_PHIX_REMOVAL_ALIGN(
+            ch_short_reads_hostremoved,
+            BOWTIE2_PHIX_REMOVAL_BUILD.out.index
+        )
+        ch_short_reads_phixremoved = BOWTIE2_PHIX_REMOVAL_ALIGN.out.reads
+        ch_versions = ch_versions.mix(BOWTIE2_PHIX_REMOVAL_ALIGN.out.versions.first())
+        ch_multiqc_files = ch_multiqc_files.mix(BOWTIE2_PHIX_REMOVAL_ALIGN.out.log)
+    }
+    else {
+        ch_short_reads_phixremoved = ch_short_reads_hostremoved
+    }
+
+    if (!(params.keep_phix && params.skip_clipping && !(params.host_genome || params.host_fasta))) {
+        FASTQC_TRIMMED(
+            ch_short_reads_phixremoved
+        )
+        ch_versions = ch_versions.mix(FASTQC_TRIMMED.out.versions)
+        ch_multiqc_files = ch_multiqc_files.mix(FASTQC_TRIMMED.out.zip)
+    }
+
+    // Run/Lane merging
+
+    ch_short_reads_forcat = ch_short_reads_phixremoved
+        .map { meta, reads ->
+            def meta_new = meta - meta.subMap('run')
+            [meta_new, reads]
+        }
+        .groupTuple()
+        .branch { meta, reads ->
+            cat: reads.size() >= 2
+            skip_cat: true
+        }
+
+    CAT_FASTQ(ch_short_reads_forcat.cat.map { meta, reads -> [meta, reads.flatten()] })
+
+    // Ensure we don't have nests of nests so that structure is in form expected for assembly
+    ch_short_reads_catskipped = ch_short_reads_forcat.skip_cat.map { meta, reads ->
+        def new_reads = meta.single_end ? reads[0] : reads.flatten()
+        [meta, new_reads]
+    }
+
+    // Combine single run and multi-run-merged data
+    ch_short_reads = Channel.empty()
+    ch_short_reads = CAT_FASTQ.out.reads.mix(ch_short_reads_catskipped)
+    ch_versions = ch_versions.mix(CAT_FASTQ.out.versions.first())
+
+    if (params.bbnorm) {
+        if (params.coassemble_group) {
+            // Interleave pairs, to be able to treat them as single ends when calling bbnorm. This prepares
+            // for dropping the single_end parameter, but keeps assembly modules as they are, i.e. not
+            // accepting a mix of single end and pairs.
+            SEQTK_MERGEPE(
+                ch_short_reads.filter { !it[0].single_end }
+            )
+            ch_versions = ch_versions.mix(SEQTK_MERGEPE.out.versions.first())
+            // Combine the interleaved pairs with any single end libraries. Set the meta.single_end to true (used by the bbnorm module).
+            ch_bbnorm = SEQTK_MERGEPE.out.reads
+                .mix(ch_short_reads.filter { it[0].single_end })
+                .map { [[id: sprintf("group%s", it[0].group), group: it[0].group, single_end: true], it[1]] }
+                .groupTuple()
+        }
+        else {
+            ch_bbnorm = ch_short_reads
+        }
+        BBMAP_BBNORM(ch_bbnorm)
+        ch_versions = ch_versions.mix(BBMAP_BBNORM.out.versions)
+        ch_short_reads_assembly = BBMAP_BBNORM.out.fastq
+    }
+    else {
+        ch_short_reads_assembly = ch_short_reads
+    }
+
+    emit:
+    short_reads = ch_short_reads
+    short_reads_assembly = ch_short_reads_assembly
+    versions = ch_versions
+    multiqc_files = ch_multiqc_files
+}