/// Lift over coordinates using the CIGAR string
pub mod bamlift;
/// Add and remove base modifications from a bam record
pub mod basemods;
/// Center fiberseq information around a reference position
pub mod center;
/// Command line interface for fibertools-rs.
pub mod cli;
#[cfg(feature = "cnn")]
/// m6A prediction with a CNN
pub mod cnn;
/// Extract fiberseq data into plain text formats
pub mod extract;
/// m6A prediction
pub mod predict_m6a;
/// m6A prediction with a XGBoost
pub mod xgb;

use anyhow::Result;
use itertools::Itertools;
use lazy_static::lazy_static;
use rust_htslib::{bam, bam::Read};
use std::collections::HashMap;
use std::env;
use std::fs::File;
use std::io::{self, stdout, BufWriter, Write};
use std::path::PathBuf;
use std::process::exit;

const VERSION: &str = env!("CARGO_PKG_VERSION");
const BUFFER_SIZE: usize = 32 * 1024;
const PROGRESS_STYLE: &str =
    "[{elapsed_precise:.yellow}] {bar:50.cyan/blue} {human_pos:>5.cyan}/{human_len:.blue} {percent:>3.green}% {per_sec:<10.cyan}";

/// Get a buffered output writer from stdout or a file
fn get_output(path: Option<PathBuf>) -> Result<Box<dyn Write + Send + 'static>> {
    let writer: Box<dyn Write + Send + 'static> = match path {
        Some(path) => {
            if path.as_os_str() == "-" {
                Box::new(BufWriter::with_capacity(BUFFER_SIZE, stdout()))
            } else {
                Box::new(BufWriter::with_capacity(BUFFER_SIZE, File::create(path)?))
            }
        }
        None => Box::new(BufWriter::with_capacity(BUFFER_SIZE, stdout())),
    };
    Ok(writer)
}

/// unzip a vector of tuples
pub fn unzip_to_vectors<T, U>(vec: Vec<(T, U)>) -> (Vec<T>, Vec<U>) {
    vec.into_iter().unzip()
}

/// join a vector with commas
pub fn join_by_str<'a, I, Z>(vals: I, sep: &str) -> String
where
    I: IntoIterator<Item = Z>,
    Z: ToString + 'a,
{
    vals.into_iter().map(|v| v.to_string() + sep).collect()
}

/// Write to stdout if - or the file specified by a path
pub fn writer(filename: &str) -> Result<Box<dyn Write>> {
    //let ext = Path::new(filename).extension();
    let path = PathBuf::from(filename);
    let buffer = get_output(Some(path))?; //.expect("Error: cannot create output file");
    Ok(buffer)
}

/// Open bam file
pub fn bam_reader(bam: &str, threads: usize) -> bam::Reader {
    let mut bam = if bam == "-" {
        bam::Reader::from_stdin().unwrap_or_else(|_| panic!("Failed to open bam from stdin"))
    } else {
        bam::Reader::from_path(bam).unwrap_or_else(|_| panic!("Failed to open {}", bam))
    };
    bam.set_threads(threads).unwrap();
    bam
}

/// Write to a bam file.
pub fn bam_writer(out: &str, template_bam: &bam::Reader, threads: usize) -> bam::Writer {
    let mut header = bam::Header::from_template(template_bam.header());

    // add to the header
    let header_string = String::from_utf8_lossy(&header.to_bytes()).to_string();
    let ft_count = header_string.matches("PP:ft").count();
    let mut header_rec = bam::header::HeaderRecord::new(b"PG");
    header_rec.push_tag(b"ID", &format!("ft.{}", ft_count + 1));
    header_rec.push_tag(b"PP", &format!("ft.{}", ft_count));
    header_rec.push_tag(b"PN", &"fibertools-rs");
    header_rec.push_tag(b"VN", &VERSION);
    let cli = env::args().join(" ");
    header_rec.push_tag(b"CL", &cli);
    header.push_record(&header_rec);
    log::trace!("{:?}", String::from_utf8_lossy(&header.to_bytes()));

    // make the writer
    let mut out = if out == "-" {
        bam::Writer::from_stdout(&header, bam::Format::Bam).unwrap()
    } else {
        bam::Writer::from_path(out, &header, bam::Format::Bam).unwrap()
    };
    out.set_threads(threads).unwrap();
    out
}

pub struct FiberOut {
    pub m6a: Option<Box<dyn Write>>,
    pub cpg: Option<Box<dyn Write>>,
    pub msp: Option<Box<dyn Write>>,
    pub nuc: Option<Box<dyn Write>>,
    pub all: Option<Box<dyn Write>>,
    pub reference: bool,
    pub simplify: bool,
    pub quality: bool,
    pub min_ml_score: u8,
    pub full_float: bool,
}

impl FiberOut {
    #[allow(clippy::too_many_arguments)]
    pub fn new(
        m6a: &Option<String>,
        cpg: &Option<String>,
        msp: &Option<String>,
        nuc: &Option<String>,
        all: &Option<String>,
        reference: bool,
        simplify: bool,
        quality: bool,
        min_ml_score: u8,
        full_float: bool,
    ) -> Result<Self> {
        let m6a = match m6a {
            Some(m6a) => Some(writer(m6a)?),
            None => None,
        };
        let cpg = match cpg {
            Some(cpg) => Some(writer(cpg)?),
            None => None,
        };
        let msp = match msp {
            Some(msp) => Some(writer(msp)?),
            None => None,
        };
        let nuc = match nuc {
            Some(nuc) => Some(writer(nuc)?),
            None => None,
        };
        let all = match all {
            Some(all) => Some(writer(all)?),
            None => None,
        };
        // set to zero
        let mut min_ml_score = min_ml_score;
        if full_float {
            min_ml_score = 0;
        }

        Ok(FiberOut {
            m6a,
            cpg,
            msp,
            nuc,
            all,
            reference,
            simplify,
            quality,
            min_ml_score,
            full_float,
        })
    }
}

/// write to a file, but don't error on broken pipes
pub fn write_to_file(out: &str, file: &mut Box<dyn Write>) {
    let out = write!(file, "{}", out);
    if let Err(err) = out {
        if err.kind() == io::ErrorKind::BrokenPipe {
            exit(0);
        } else {
            panic!("Error: {}", err);
        }
    }
}

pub fn write_to_stdout(out: &str) {
    let mut out_f = Box::new(std::io::stdout()) as Box<dyn Write>;
    write_to_file(out, &mut out_f);
}

// This is a bam chunk reader
use colored::Colorize;
use std::time::Instant;

struct BamChunk<'a> {
    bam: bam::Records<'a, bam::Reader>,
    chunk_size: usize,
}

// The `Iterator` trait only requires a method to be defined for the `next` element.
impl<'a> Iterator for BamChunk<'a> {
    // We can refer to this type using Self::Item
    type Item = Vec<bam::Record>;

    // The return type is `Option<T>`:
    //     * When the `Iterator` is finished, `None` is returned.
    //     * Otherwise, the next value is wrapped in `Some` and returned.
    // We use Self::Item in the return type, so we can change
    // the type without having to update the function signatures.
    fn next(&mut self) -> Option<Self::Item> {
        let start = Instant::now();
        let mut cur_vec = vec![];
        for r in self.bam.by_ref().take(self.chunk_size) {
            cur_vec.push(r.unwrap())
        }
        // return
        if cur_vec.is_empty() {
            None
        } else {
            let duration = start.elapsed().as_secs_f64();
            log::info!(
                "Read {} bam records at {}.",
                format!("{:}", cur_vec.len()).bright_magenta().bold(),
                format!("{:.2?} reads/s", cur_vec.len() as f64 / duration)
                    .bright_cyan()
                    .bold(),
            );
            Some(cur_vec)
        }
    }
}

#[derive(Clone)]
pub enum PbChem {
    Two,
    TwoPointTwo,
}

pub fn find_pb_polymerase(header: &bam::Header) -> PbChem {
    lazy_static! {
        static ref CHEMISTRY_MAP: HashMap<String, PbChem> = HashMap::from([
            // regular 2.0
            ("101-789-500".to_string(), PbChem::Two),
            // this is actually 2.1 we didn't have training data for it
            ("101-820-500".to_string(), PbChem::Two),
            // regular 2.2
            ("101-894-200".to_string(), PbChem::TwoPointTwo),
            // is really 3.1 but has polymerase of 2.1, and we need to make that 2.0
            ("102-194-200".to_string(), PbChem::Two),
            // is really 3.2 but has polymerase of 2.2
            ("102-194-100".to_string(), PbChem::TwoPointTwo),
            // Revio has kinetics most similar to 2.2
            ("102-739-100".to_string(), PbChem::TwoPointTwo)
        ]);
    }
    lazy_static! {
        static ref MM_DS: regex::Regex =
            regex::Regex::new(r".*READTYPE=([^;]+);.*BINDINGKIT=([^;]+);").unwrap();
    }
    let z = header.to_hashmap();
    let rg = z.get("RG").expect("RG tag missing from bam file");
    let mut read_type = "";
    let mut binding_kit = "";
    for tag in rg {
        for (tag, val) in tag {
            if tag == "DS" {
                for cap in MM_DS.captures_iter(val) {
                    read_type = cap.get(1).map_or("", |m| m.as_str());
                    binding_kit = cap.get(2).map_or("", |m| m.as_str());
                }
            }
        }
    }
    // make sure read-type is CCS
    assert_eq!(read_type, "CCS");
    // grab chemistry
    let chemistry = CHEMISTRY_MAP.get(binding_kit).unwrap_or_else(|| {
        log::warn!(
            "Polymerase for BINDINGKIT={} not found. Defaulting to ML model made with 2.2",
            binding_kit
        );
        &PbChem::TwoPointTwo
    });
    chemistry.clone()
}