use std::io::{self, BufRead, Write};
use std::str::FromStr;
use textgraph::graph;
use textgraph::parseopts::{parseopts, Opts};

/// Will graph what comes in through stdin,
/// For each new line, the graph will be re-drawn.
///
/// # Arguments
///
/// * `opts` -  textgraph::parseopts::Opts
fn filter(opts: Opts) {
    //print!("\x1b[?1049h");

    let mut x_values: Vec<f64> = Vec::new();
    let mut y_values: Vec<f64> = Vec::new();
    let mut i = 0.0;

    let stdin = io::stdin();
    for line in stdin.lock().lines() {
        i += 1.0;
        let line = line.expect("Could not read...");

        let y = f64::from_str(line.as_str()).expect("TG7 invalid number");
        y_values.push(y);
        x_values.push(i);

        let mut gb = graph::GraphBuilder::new(&x_values, &y_values, opts.width, opts.height);
        gb.axis(opts.axis);
        gb.graph_type(opts.graph_type.clone());
        if let Some(n) = opts.last_n {
            gb.keep_tail(n as usize);
        }

        //print!("\x1B[2J\x1B[H");
        println!("{}", gb.build());
    }

    //print!("\x1B[?1049l");
    io::stdout().flush().unwrap();
}

/// Will graph the contents of a file
/// This assumes opts.in_file is Some, or it will panic!
/// Currently this only supports a single column, with no x-values
///
/// # Arguments
///
/// * `opts` -  textgraph::parseopts::Opts
fn graph_file(opts: Opts) {
    let raw_y_values = std::fs::read_to_string(opts.in_file.clone().unwrap()).expect("TG6");

    let mut y_values: Vec<f64> = Vec::new();
    let mut x_values: Vec<f64> = Vec::new();
    for (i, line) in raw_y_values.lines().enumerate() {
        y_values.push(f64::from_str(line).expect("TG7"));
        x_values.push(i as f64);
    }

    let mut gb = graph::GraphBuilder::new(&x_values, &y_values, opts.width, opts.height);
    gb.axis(opts.axis);
    gb.graph_type(opts.graph_type);
    if let Some(n) = opts.last_n {
        gb.keep_tail(n as usize);
    }
    println!("{}", gb.build());
}

/// Main entry point for the binary of textgraph
fn main() {
    let opts = parseopts();

    if opts.in_file.is_none() {
        filter(opts);
    } else {
        graph_file(opts);
    }
}