use std::{
    sync::{Arc, Mutex, RwLock},
    thread::JoinHandle,
};

use cell::{Cell, CellRef};
use mlua::prelude::*;
use register::{Register, SheetId};

pub mod cell;
pub mod register;

#[derive(Debug, Default)]
pub struct Sheet {
    id: register::SheetId,
    rows: Vec<Vec<Cell>>,
    progress: Mutex<u8>,
}

impl Sheet {
    pub(self) fn new(width: usize, height: usize, id: register::SheetId) -> Self {
        Self {
            id,
            rows: vec![vec![Cell::new_empty(); width]; height],
            progress: Mutex::new(0),
        }
    }

    pub fn set_cell(&mut self, row: usize, column: usize, cell: Cell) {
        if row < self.height() && column < self.width() {
            self.rows[row][column] = cell
        }
    }

    pub fn get_cell<'a>(&'a self, row: usize, column: usize) -> Option<&'a Cell> {
        if let Some(r) = self.rows.get(row) {
            if let Some(_) = r.get(column) {
                return Some(&self.rows[row][column]);
            }
        }

        None
    }

    pub fn get_ref(&self, row: usize, column: usize) -> Option<CellRef> {
        CellRef::new(self.id, row, column)
    }

    pub fn height(&self) -> usize {
        self.rows.len()
    }

    pub fn set_height(&mut self, mut height: usize) {
        height = height.max(1);
        self.rows
            .resize(height, vec![Cell::new_empty(); self.width()])
    }

    pub fn width(&self) -> usize {
        self.rows.get(0).map(|r| r.len()).unwrap_or(1)
    }

    pub fn set_width(&mut self, mut width: usize) {
        width = width.max(1);
        for row in self.rows.iter_mut() {
            row.resize(width, Cell::new_empty());
        }
    }

    pub fn id(&self) -> register::SheetId {
        self.id
    }

    pub fn apply(&mut self, other: Sheet) {
        self.rows = other.rows;
    }

    pub fn progress(&self) -> u8 {
        *self.progress.lock().unwrap()
    }
}

impl Clone for Sheet {
    fn clone(&self) -> Self {
        Sheet {
            id: self.id,
            rows: self.rows.clone(),
            progress: Mutex::new(0),
        }
    }
}

struct SheetLuaRef {
    id: SheetId,
}

impl SheetLuaRef {
    pub fn new(id: SheetId) -> Self {
        Self { id }
    }
}

impl LuaUserData for SheetLuaRef {
    fn add_fields<'lua, F: mlua::UserDataFields<'lua, Self>>(fields: &mut F) {
        fields.add_field_method_get("width", |_, luaref| {
            Ok(Register::get(luaref.id).unwrap().read().unwrap().width())
        });

        fields.add_field_method_get("height", |_, luaref| {
            Ok(Register::get(luaref.id).unwrap().read().unwrap().height())
        });
    }

    fn add_methods<'lua, M: mlua::UserDataMethods<'lua, Self>>(methods: &mut M) {
        methods.add_method_mut("cell", |lua, luaref, (row, column): (usize, usize)| {
            if let Some(_) = Register::get(luaref.id) {
                Ok(CellRef::new(luaref.id, row, column).into_lua(lua).unwrap())
            } else {
                Ok(LuaValue::Nil)
            }
        })
    }
}

pub trait EvalFunction {
    fn eval_function(
        &self,
        func: String,
        range: Vec<(usize, usize)>,
    ) -> JoinHandle<Result<Sheet, String>>;
}

impl EvalFunction for Arc<RwLock<Sheet>> {
    fn eval_function(
        &self,
        func_text: String,
        range: Vec<(usize, usize)>,
    ) -> JoinHandle<Result<Sheet, String>> {
        let this = Arc::clone(self);
        std::thread::spawn(move || {
            let read_sheet = this.read().unwrap();
            *read_sheet.progress.lock().unwrap() = 0;
            let mut sheet = read_sheet.clone();

            let lua = crate::lua::new_instance().unwrap();
            let result = lua
                .load(func_text.clone())
                .set_name("Temp Script")
                .eval::<LuaFunction>();

            match result {
                Ok(func) => {
                    for (i, (row, column)) in range.iter().enumerate() {
                        *read_sheet.progress.lock().unwrap() = (i * 100 / range.len()) as u8;
                        let cellref = read_sheet.get_ref(*row, *column);
                        match func.call::<_, Cell>(cellref) {
                            Ok(cell) => sheet.set_cell(*row, *column, cell),
                            Err(error) => return Err(error.to_string()),
                        }
                    }
                }
                Err(error) => return Err(error.to_string()),
            }

            Ok(sheet)
        })
    }
}