#![allow(unused)]

#[macro_use]
extern crate slog;
#[macro_use]
extern crate markets;

use std::io::{self, prelude::*};
use std::fs;
use std::path::{Path, PathBuf};
use std::time::*;
use pretty_toa::ThousandsSep;
use structopt::StructOpt;
use serde::{Serialize, Deserialize};
use slog::Drain;
use chrono::{DateTime, Utc, NaiveDateTime};
use markets::crypto::{Exchange, Ticker, Side, Currency};

macro_rules! fatal { ($fmt:expr, $($args:tt)*) => {{
    eprintln!($fmt, $($args)*);
    std::process::exit(1);
}}}

const PROGRESS_EVERY: usize = 1024 * 1024 * 4;


#[structopt(rename_all="kebab-case")]
#[derive(Debug, StructOpt)]
enum Opt {

    /// Filter trades-csv by start,end range and save subset to output-path
    /// 
    /// Note: csv assumed to be pre-sorted by time (ascending)
    ///
    Range {

        /// Path to CSV file with trades data
        #[structopt(short = "f", long = "trades-csv")]
        #[structopt(parse(from_os_str))]
        trades_csv: PathBuf,

        /// Where to save the query results (CSV output)
        #[structopt(short = "o", long = "output-path")]
        #[structopt(parse(from_os_str))]
        output_path: PathBuf,

        /// rfc3339 format ("YYYY-MM-DDTHH:MM:SSZ")
        #[structopt(short = "s", long = "start")]
        start: DateTime<Utc>,

        /// rfc3339 format ("YYYY-MM-DDTHH:MM:SSZ")
        #[structopt(short = "e", long = "end")]
        end: DateTime<Utc>,

    },

    /// Convert the original csv info a format ready to be ingested via COPY
    ///
    /// 1. server_time of 0 -> NULL
    /// 2. side of "na" -> NULL
    PrepPostgres {

        /// Path to CSV file with trades data
        #[structopt(short = "f", long = "trades-csv")]
        #[structopt(parse(from_os_str))]
        trades_csv: PathBuf,

        /// Where to save the query results (CSV output)
        #[structopt(short = "o", long = "output-path")]
        #[structopt(parse(from_os_str))]
        output_path: PathBuf,
    },

    ListCodes,

    /*
    Binarize {
        /// Path to CSV file with trades data
        #[structopt(short = "f", long = "trades-csv")]
        #[structopt(parse(from_os_str))]
        trades_csv: PathBuf,

        /// Where to save the binary-serialized data
        #[structopt(short = "o", long = "output-path")]
        #[structopt(parse(from_os_str))]
        output_path: PathBuf,

    }
    */


}

#[derive(Deserialize)]
struct Trade {
    /// Unix nanoseconds
    pub time: u64,
    pub exch: Exchange,
    pub ticker: Ticker,
    //pub side: Option<Side>,
    pub price: f64,
    pub amount: f64,
}

#[derive(Deserialize, Debug)]
struct PgBuilder<'a> {
    pub time: u64,
    pub exch: Exchange,
    pub ticker: Ticker,
    pub side: Option<&'a str>,
    pub price: f64,
    pub amount: f64,
    pub server_time: u64,
}

#[derive(Serialize, Debug)]
struct PgRow {
    pub time: DateTime<Utc>,
    pub exch: u8,
    pub base: u8,
    pub quote: u8,
    pub amount: f64,
    pub price: f64,
    pub side: Option<u8>,
    pub server_time: Option<DateTime<Utc>>,
}

fn nanos_to_utc(nanos: u64) -> DateTime<Utc> {
    const ONE_SECOND: u64 = 1_000_000_000;
    let sec: i64 = (nanos / ONE_SECOND) as i64;
    let nsec: u32 = (nanos % ONE_SECOND) as u32;
    let naive = NaiveDateTime::from_timestamp(sec, nsec);
    DateTime::from_utc(naive, Utc)
}

fn per_sec(n: usize, span: Duration) -> f64 {
    if n == 0 || span < Duration::from_micros(1) { return 0.0 }
    let s: f64 = span.as_nanos() as f64 / 1e9f64;
    n as f64 / s
}

fn nanos(utc: DateTime<Utc>) -> u64 {
    (utc.timestamp() as u64) * 1_000_000_000_u64 + (utc.timestamp_subsec_nanos() as u64)
}

fn run(start: Instant, logger: &slog::Logger) -> Result<usize, String> {
    let opt = Opt::from_args();

    let mut n = 0;

    match opt {
        Opt::PrepPostgres { trades_csv, output_path } => {
            let logger = logger.new(o!("cmd" => "prep-postgres"));

            info!(logger, "beginning prep-postgres cmd";
                "trades_csv" => %trades_csv.display(),
                "output_path" => %output_path.display(),
            );

            if ! trades_csv.exists() { return Err(format!("--trades-csv path does not exist: {}", trades_csv.display())) }

            info!(logger, "opening trades_csv file");

            let rdr = fs::File::open(&trades_csv)
                .map_err(|e| format!("opening trades csv file failed: {} (tried to open {})", e, trades_csv.display()))?;

            let rdr = io::BufReader::new(rdr);

            let mut rdr = csv::Reader::from_reader(rdr);

            info!(logger, "opening output file for writing");

            let wtr = fs::File::create(&output_path)
                .map_err(|e| format!("opening output file failed: {} (tried to open {} for writing)", e, output_path.display()))?;

            let wtr = io::BufWriter::new(wtr);

            let mut wtr = csv::Writer::from_writer(wtr);

            let headers: csv::StringRecord = rdr.headers().map_err(|e| format!("failed to parse CSV headers: {}", e))?.clone();
            let mut row = csv::StringRecord::new();

            //wtr.write_record(&headers).map_err(|e| format!("writing headers row failed: {}", e))?;

            while rdr.read_record(&mut row)
                .map_err(|e| {
                    format!("reading row {} failed: {}", (n+1).thousands_sep(), e)
                })?
            {
                let bldr: PgBuilder = row.deserialize(Some(&headers)).map_err(|e| format!("deser failed: {}", e))?;
                let PgBuilder { time, exch, ticker, side, price, amount, server_time } = bldr;
                let time = nanos_to_utc(time);
                let exch = u8::from(exch);
                let base = u8::from(ticker.base);
                let quote = u8::from(ticker.quote);
                let side: Option<u8> = match side {
                    Some("bid") => Some(1),
                    Some("ask") => Some(2),
                    _ => None,
                };
                let server_time = match server_time {
                    0 => None,
                    x => Some(nanos_to_utc(x)),
                };
                let pg_row = PgRow { time, exch, base, quote, amount, price, side, server_time };

                wtr.serialize(&pg_row).map_err(|e| format!("serializing PgRow to csv failed: {}", e))?;

                n += 1;
                if n % PROGRESS_EVERY == 0 {
                    info!(logger, "parsing/writing csv rows"; "n" => %n.thousands_sep());
                }
            }
        }

        Opt::ListCodes => {
            println!("side: {:?} {}", Side::Bid, u8::from(Side::Bid));
            println!("side: {:?} {}", Side::Ask, u8::from(Side::Ask));
            println!();

            for exch in Exchange::all() { 
                println!("INSERT INTO exchanges (id, symbol) VALUES ({}, '{}');", u8::from(exch), exch.as_str());
            }

            for currency in Currency::all() { 
                println!("INSERT INTO currencies (id, symbol) VALUES ({}, '{}');", u8::from(currency), currency.as_str());
            }
        }

        Opt::Range { trades_csv, output_path, start, end } => {
            let logger = logger.new(o!("cmd" => "range"));

            info!(logger, "beginning range cmd";
                "trades_csv" => %trades_csv.display(),
                "output_path" => %output_path.display(),
                "start" => %start,
                "end" => %end,
            );

            if ! trades_csv.exists() { return Err(format!("--trades-csv path does not exist: {}", trades_csv.display())) }

            info!(logger, "opening trades_csv file");

            let rdr = fs::File::open(&trades_csv)
                .map_err(|e| format!("opening trades csv file failed: {} (tried to open {})", e, trades_csv.display()))?;

            let rdr = io::BufReader::new(rdr);

            let mut rdr = csv::Reader::from_reader(rdr);

            info!(logger, "opening output file for writing");

            let wtr = fs::File::create(&output_path)
                .map_err(|e| format!("opening output file failed: {} (tried to open {} for writing)", e, output_path.display()))?;

            let wtr = io::BufWriter::new(wtr);

            let mut wtr = csv::Writer::from_writer(wtr);

            let headers: csv::ByteRecord = rdr.byte_headers().map_err(|e| format!("failed to parse CSV headers: {}", e))?.clone();

            let time_col: usize = headers.iter().position(|x| x == b"time").ok_or_else(|| {
                String::from("no column in headers named 'time'")
            })?;

            let mut row = csv::ByteRecord::new();

            let start_nanos = nanos(start);
            let end_nanos = nanos(end);

            let mut n_written = 0;
            let mut time: u64 = 0;

            info!(logger, "writing headers row to output file");
            wtr.write_byte_record(&headers).map_err(|e| format!("writing csv headers row failed: {}", e))?;

            info!(logger, "entering csv parsing loop");

            'a: while rdr.read_byte_record(&mut row)
                .map_err(|e| {
                    format!("reading row {} failed: {}", (n+1).thousands_sep(), e)
                })?
            {
                let time_bytes = row.get(time_col).ok_or_else(|| "time column not present for row")?;

                time = atoi::atoi(time_bytes).ok_or_else(|| {
                    format!("failed to parse 'time' col value '{}' as integer", std::str::from_utf8(time_bytes).unwrap_or("utf8err"))
                })?;

                n += 1;

                if n % PROGRESS_EVERY == 0 {
                    info!(logger, "parsing csv rows"; "n" => %n.thousands_sep(), "n_written" => %n_written.thousands_sep());
                }

                if time < start_nanos { continue 'a }

                if time > end_nanos { break 'a }

                wtr.write_byte_record(&row).map_err(|e| format!("writing parsed csv row to output file failed: {}", e))?;

                n_written += 1;
            }

            info!(logger, "broke out of read csv loop"; "time" => time, "end_nanos" => end_nanos, "n" => %n.thousands_sep(), "n_written" => %n_written.thousands_sep());

            info!(logger, "dropping wtr");

            drop(wtr);
        }
    }

    Ok(n)
}

fn main() {
    let start = Instant::now();

    let decorator = slog_term::TermDecorator::new().stdout().force_color().build();
    let drain = slog_term::FullFormat::new(decorator).use_utc_timestamp().build().fuse();
    let drain = slog_async::Async::new(drain).chan_size(1024 * 64).thread_name("recv".into()).build().fuse();
    let logger = slog::Logger::root(drain, o!("version" => structopt::clap::crate_version!()));

    match run(start, &logger) {
        Ok(n) => {
            let took = Instant::now() - start;
            info!(logger, "finished in {:?}", took;
                "n rows" => %n.thousands_sep(),
                "rows/sec" => &((per_sec(n, took) * 100.0).round() / 10.0).thousands_sep(),
            );
        }

        Err(e) => {
            crit!(logger, "run failed: {:?}", e);
            eprintln!("\n\nError: {}", e);
            std::thread::sleep(Duration::from_millis(100));
            std::process::exit(1);
        }
    }

}