handle case with one read and --support 1

should solve issue reported in #4

src/genotype.rs

@@ -145,6 +145,19 @@ fn genotype_repeat(
                 insertions.len().to_string(),
             ));
         }
+        // handle the special case where there is only 1 read for the repeat (but minimal support is 1 so it passes)
+        // no need to make a consensus or phase, just report the single read
+        if insertions.len() == 1 {
+            return Ok(crate::vcf::VCFRecord::single_read(
+                &insertions[0],
+                repeat,
+                &repeat_ref_seq,
+                all_insertions,
+                reads.ps,
+                flags,
+            ));
+        }
+
         debug!("{repeat}: Phasing {} insertions", insertions.len(),);
         let phased = crate::phase_insertions::split(&insertions, repeat, args.find_outliers);
         match phased.hap2 {

src/phase_insertions.rs

@@ -45,8 +45,8 @@ pub fn split(
     let mut clusters = vec![];
     // create a vector with candidate haplotype-clusters
     let mut haplotype_clusters = vec![];
-    // clusters have to represent at least 20% of the reads
-    let min_cluster_size = (insertions.len() as f32 / 10.0) as usize;
+    // clusters have to represent at least 10% of the reads, but never less than 1
+    let min_cluster_size = max((insertions.len() as f32 / 10.0) as usize, 1);
     debug!("{repeat}: Minimum cluster size: {}", min_cluster_size);
 
     for (index, step) in dend.steps().iter().enumerate() {

src/vcf.rs

@@ -184,6 +184,44 @@ impl VCFRecord {
             allele: (".".to_string(), ".".to_string()),
         }
     }
+
+    pub fn single_read(
+        seq: &str,
+        repeat: &crate::repeats::RepeatInterval,
+        repeat_ref_seq: &str,
+        all_insertions: Option<Vec<String>>,
+        ps: Option<u32>,
+        flag: Vec<String>,        
+    ) -> VCFRecord {
+                let somatic_info_field = match all_insertions {
+            Some(somatic_insertions) => {
+                format!(";SEQS={}", somatic_insertions.join(","))
+            }
+            None => "".to_string(),
+        };
+        VCFRecord {
+            chrom: repeat.chrom.clone(),
+            start: repeat.start,
+            end: repeat.end,
+            ref_seq: repeat_ref_seq.to_string(),
+            alt_seq: Some(seq.to_string()),
+            length: ((seq.len() as u32 - (repeat.end - repeat.start)).to_string(), ".".to_string()),
+            full_length: ((seq.len() as u32).to_string(), ".".to_string()),
+            support: ("1".to_string(), ".".to_string()),
+            std_dev: (".".to_string(), ".".to_string()),
+            score: (".".to_string(), ".".to_string()),
+            somatic_info_field,
+            outliers: "".to_string(),
+            ps,
+            flags : if flag.is_empty() {
+                "".to_string()
+            } else {
+                format!("{};", flag.join(";"))
+            },
+            allele: (".".to_string(), ".".to_string()),
+        }
+
+    }
 }
 
 impl fmt::Display for VCFRecord {