use super::Rect;
use std::io::Write;

use crossterm::{
    cursor::{MoveDown, MoveTo, MoveToColumn},
    queue, terminal,
};

use crate::Result;

use super::{Cell, Pos};

pub struct View {
    cells: Vec<Cell>,
    width: u16,
    #[allow(dead_code)]
    height: u16,
}

impl View {
    pub fn new(width: u16, height: u16) -> Self {
        Self {
            width,
            height,
            cells: vec![Cell::default(); (width * height) as usize],
        }
    }

    pub fn fullscreen() -> Self {
        let (width, height) = terminal::size().expect("Couldnt detect terminal size");
        Self {
            width,
            height,
            cells: vec![Cell::default(); (width * height) as usize],
        }
    }

    pub fn get(&self, pos: Pos) -> Option<&Cell> {
        self.cells.get((pos.y() * self.width + pos.x()) as usize)
    }

    pub fn set(&mut self, pos: Pos, cell: Cell) {
        self.cells[(pos.y() * self.width + pos.x()) as usize] = cell;
    }

    pub fn fill(&mut self, rect: Rect, cell: Cell) {
        for y in rect.pos.y()..rect.pos.y() + rect.height {
            for x in rect.pos.x()..rect.pos.x() + rect.width {
                self.set(Pos::new(x, y), cell);
            }
        }
    }

    pub fn fill_all(&mut self, cell: Cell) {
        self.cells.fill(cell);
    }

    pub fn merge(&mut self, pos: Pos, view: View) {
        for (idx, line) in view.cells.chunks(view.width as usize).enumerate() {
            let start = ((pos.y() + idx as u16) * self.width + pos.x()) as usize;
            let end = start + line.len();
            self.cells.splice(start..end, line.iter().cloned());
        }
    }

    pub fn render(&mut self, pos: Pos, output: &mut impl Write) -> Result<()> {
        queue!(output, MoveTo(pos.x(), pos.y()))?;
        for line in self.cells.chunks(self.width as usize) {
            for cell in line {
                cell.render(output)?;
            }
            queue!(output, MoveDown(1))?;
            queue!(output, MoveToColumn(pos.x()))?;
        }
        Ok(())
    }
}