use duct::cmd;

fn main() {
    let fasta_ref_path = "/home/thomas/NGS/ref/hg19.fa";
    let sequence = "
    CATTATATTCTTTTTTACAGTGCCACGGGTATATTTAGTAAACATTGAAATGTGTGGTTG
    GAATTGTTCATCACTGATGTTTTTGGTGATATTTGTTTATGTTCTGAAGCTATTGCTGTA
    GACCAACATGGAGTAAACAGAAAATAATTGGGACACAGGGGCAATAAAACTCATATATTA
    TTTTCCCATGACACTCAGAGGACTCTTCCCAATGCTGAGACATACATAGCGGGTCACGGC
    TGGGTGTTTTTGGACAAAGGCTTAATGCACTCCAACCTAGGTCCAAGAACTACAACGGCT
    GCTGCCGGCCGGGCCCGCTCCCTGGCCTACCTTGCACAAGAAGTCGACATCGTAGAAGGC
    GGACAGAAGTGTGGTCGACATGTTTCTGGAA"
    .replace("\n", "")
    .replace(" ", "");

    println!("sequence len: {}", sequence.len());
    println!(">sequence\n{}", sequence);

    let aln = bwa_aln(fasta_ref_path, &sequence);

    aln.iter()
    .for_each(|e| {
        println!("seq len: {:?}", e.seq.len());
        println!("cigar: {:?}", e.cigar.0);
        println!("reverse: {:?}", is_reverse(e.flag));
        println!("cigar len: {:?}", e.cigar.len());
        println!("pos: {}:{}", e.ref_name, e.pos);
        if is_reverse(e.flag) {
            println!("{:?}", revcomp(&e.seq));
            println!("{:?}", e.cigar.expand());

            // println!("{:?}", e.cigar.expand().chars().rev().collect::<String>());
        } else {
            println!("{:?}", e.seq);
            println!("{:?}", e.cigar.expand());
        }
        
        println!("-------------------------------")
        // println!("{:?}", e.seq.len() == e.cigar.len() as usize);
    });
}

pub fn bwa_aln(fasta_ref_path: &str, sequence: &str) -> Vec<Sam> {
    let stdout = cmd!("echo", "-e", format!("\">sequence_to_query\n{}\"", sequence))
    .pipe(cmd!("bwa", "mem", fasta_ref_path, "-"))
    .stdout_capture()
    .stderr_capture()
    .read().unwrap();

    let alignements: Vec<Sam> = stdout.split("\n")
    .filter(|e| e.contains("sequence_to_query"))
    .map(|e| parse_sam_output(e))
    .collect();
    
    alignements
}

#[derive(Debug, Clone)]
pub struct Sam {
    pub qname   : String,
    pub flag    : u16,
    pub ref_name: String,
    pub pos     : i32,
    pub mapq    : i32,
    pub cigar   : Cigar,
    pub rnext   : String,
    pub pnext   : String,
    pub tlen    : String,
    pub seq     : String
}

fn parse_sam_output(sam_string: &str) -> Sam {
    let mut split = sam_string.split("\t");
    Sam {
        qname   : split.next().unwrap().to_string(),
        flag    : split.next().unwrap().parse().unwrap(),
        ref_name: split.next().unwrap().to_string(),
        pos     : split.next().unwrap().parse().unwrap(),
        mapq    : split.next().unwrap().parse().unwrap(),
        cigar   : Cigar::new_from_str(&split.next().unwrap().to_string()),
        rnext   : split.next().unwrap().to_string(),
        pnext   : split.next().unwrap().to_string(),
        tlen    : split.next().unwrap().to_string(),
        seq     : split.next().unwrap().to_string()
    }
}

#[derive(Debug, Clone)]
pub struct Cigar(Vec<(String, u32)>);

impl Cigar {
    pub fn new_from_str(cigar_str: &str) -> Cigar {
        let mut res: Vec<(String, u32)> = Vec::new();
        let mut num_acc = String::new();
        for c in cigar_str.split("") {
            if c != "" { match c.parse::<usize>() {
                Ok(_) => num_acc.push_str(c), // if a number added to the accumulator
                Err(_) => {
                    let current_add = num_acc.parse::<u32>().unwrap();
                    num_acc = "".to_string();

                    // if begin by N...
                    res.push((c.to_string(), current_add));
                }
            }}
        }
        Cigar(res)
    }

    pub fn len(&self) -> u32 {
        self.0.iter()
        .map(|e| e.1)
        .reduce(|acc, e| acc + e)
        .unwrap()
    }

    pub fn expand(&self) -> String {
        let mut res = String::new();
        for (op, n) in self.0.iter() {
            let c = op.chars().next().unwrap();
            for _ in 0..(*n) {
                res.push(c);
            }
        }
        res
    }
}

fn is_reverse (flag: u16) -> bool {
    flag & 0x10 == 0x10
}

pub fn revcomp(dna: &str) -> String{
    let mut rdna: String = String::with_capacity(dna.len()); 
    for c in dna.chars().rev() {
        rdna.push(switch_base(c));
    }
    rdna
}

fn switch_base(c:char) -> char {
    match c {
        'a' => 't',
        'c' => 'g',
        't' => 'a',
        'g' => 'c',
        'u' => 'a',
        'A' => 'T',
        'C' => 'G',
        'T' => 'A',
        'G' => 'C',
        'U' => 'A',
        _   => 'N'
    }
}

fn make_aln(seq_query: &str, alignements: &Vec<Sam>) {
    let consumes_query = vec!["M", "I", "S", "=", "X", "H"];
    let consumes_ref = vec!["M", "D", "N", "=", "X"];
}