use std::fs::File;
use std::io::Write;
use crate::global::{DisplayBuffer, IMG_HEIGHT, IMG_WIDTH};

pub struct View<'a> {
    pub data: &'a DisplayBuffer,
    pub viewer: fn(&DisplayBuffer) -> Result<String, std::io::Error>,
}

impl<'a> View<'a> {
    pub fn display(&self) {
        let result = (self.viewer)(self.data);
        match result {
            Ok(success_msg) => {
                println!("{}", success_msg);
            },
            Err(error_msg) => {
                eprintln!("{}", error_msg);
            }
        }
    }
}

pub mod render_viewer {
    use super::*;

    pub fn ppm_exporter(data: &DisplayBuffer) -> Result<String, std::io::Error> {
        let file_name = "output.ppm";
        let mut file = File::create(file_name)?;
        // header
        let mut txt_data = String::from("P3\n");
        txt_data.push_str(format!("{} {}\n255\n", IMG_WIDTH, IMG_HEIGHT).as_str());
        // data point
        data.iter().for_each(|row| {
            row.iter().for_each(|&pixel| {
                txt_data.push_str(&format!("{} {} {}\n", pixel.r, pixel.g, pixel.b));
            })
        });
        file.write_all(txt_data.as_bytes())?;
        Ok(format!("Output rendered to file {}", file_name))
    }
}