use log::{trace};

use crate::constants::*;

#[derive(Clone, Copy)]
pub struct Chip8SystemMemory {
    memory: [u8; CHIP8_MEMORY_SIZE as usize],
}

impl Default for Chip8SystemMemory {
    fn default() -> Self {

        let mut x = Chip8SystemMemory {
            memory: [0x00; CHIP8_MEMORY_SIZE as usize],
        };

        x.load_fonts_to_memory();
        x.load_schip_fonts_to_memory();
        x
    }
}
impl Chip8SystemMemory {
    
    pub fn new() -> Self {
        Chip8SystemMemory {
            memory: [0x00; CHIP8_MEMORY_SIZE as usize],
        }
    }

    pub fn peek(&self, address: u16) -> u8 {
        trace!("PEEK: {} / {}", address, self.memory[address as usize].clone());
        self.memory[address as usize]
    }

    pub fn poke(&mut self, address: u16, value: u8)  {
        trace!("POKE: {} / {} to {}", address, self.memory[address as usize], value);
        self.memory[address as usize] = value;
    }

    pub fn load_program(&mut self, program_to_load: Box<Vec<u8>>) {
        for load_index in 0..program_to_load.len() {
            self.poke((load_index + 0x200) as u16, program_to_load[load_index]);
        }
    }

    pub fn load_fonts_to_memory(&mut self) {
        let all_font_characters = [
            CHIP8FONT_0,
            CHIP8FONT_1,
            CHIP8FONT_2,
            CHIP8FONT_3,
            CHIP8FONT_4,
            CHIP8FONT_5,
            CHIP8FONT_6,
            CHIP8FONT_7,
            CHIP8FONT_8,
            CHIP8FONT_9,
            CHIP8FONT_A,
            CHIP8FONT_B,
            CHIP8FONT_C,
            CHIP8FONT_D,
            CHIP8FONT_E,
            CHIP8FONT_F,
        ];

        for (font_index, current_font) in all_font_characters.iter().enumerate() {
            for font_mem_offset in 0..=4 {
                let real_offset = font_index * 5 + font_mem_offset;
                self.poke(real_offset as u16, current_font[font_mem_offset]);
            }
        }
    }

    pub fn load_schip_fonts_to_memory(&mut self) {
        let all_font_characters = [
            SCHIPFONT_0, SCHIPFONT_1, SCHIPFONT_2, SCHIPFONT_3,
            SCHIPFONT_4, SCHIPFONT_5, SCHIPFONT_6, SCHIPFONT_7,
            SCHIPFONT_8, SCHIPFONT_9, SCHIPFONT_A, SCHIPFONT_B,
            SCHIPFONT_C, SCHIPFONT_D, SCHIPFONT_E, SCHIPFONT_F
        ];
        for (font_index, current_font) in all_font_characters.iter().enumerate() {
            let base_offset = 0x100;
            for font_mem_offset in 0..=4 {
                let real_offset = base_offset + font_index * 0x10 + font_mem_offset;
                self.poke(real_offset as u16, current_font[font_mem_offset]);
            }
        }
    }
}