#[derive(Clone, PartialEq)]
pub struct Color(pub f64, pub f64, pub f64);

pub const COLOR_BLACK: Color = Color(0.0, 0.0, 0.0);
pub const COLOR_WHITE: Color = Color(1.0, 1.0, 1.0);
pub const COLOR_RED: Color = Color(1.0, 0.0, 0.0);

#[derive(Clone)]
pub struct Attrs {
    pub italic: bool,
    pub bold: bool,
    pub underline: bool,
    pub undercurl: bool,
    pub foreground: Option<Color>,
    pub background: Option<Color>,
    pub special: Option<Color>,
    pub reverse: bool,
    pub double_width: bool,
}

impl Attrs {
    pub fn new() -> Attrs {
        Attrs {
            foreground: None,
            background: None,
            special: None,
            italic: false,
            bold: false,
            underline: false,
            undercurl: false,
            reverse: false,
            double_width: false,
        }
    }

    fn clear(&mut self) {
        self.italic = false;
        self.bold = false;
        self.underline = false;
        self.undercurl = false;
        self.reverse = false;
        self.foreground = None;
        self.background = None;
        self.special = None;
        self.double_width = false;
    }
}

#[derive(Clone)]
pub struct Cell {
    pub ch: char,
    pub attrs: Attrs,
}

impl Cell {
    pub fn new(ch: char) -> Cell {
        Cell {
            ch: ch,
            attrs: Attrs::new(),
        }
    }

    fn clear(&mut self) {
        self.ch = ' ';
        self.attrs.clear();
    }
}

pub struct UiModel {
    pub columns: usize,
    pub rows: usize,
    cur_row: usize,
    cur_col: usize,
    model: Vec<Vec<Cell>>,
    top: usize,
    bot: usize,
    left: usize,
    right: usize,
}

impl UiModel {
    pub fn empty() -> UiModel {
        UiModel {
            columns: 0,
            rows: 0,
            cur_row: 0,
            cur_col: 0,
            model: vec![],
            top: 0,
            bot: 0,
            left: 0,
            right: 0,
        }
    }

    pub fn new(rows: u64, columns: u64) -> UiModel {
        let mut model = Vec::with_capacity(rows as usize);
        for i in 0..rows as usize {
            model.push(Vec::with_capacity(columns as usize));
            for _ in 0..columns as usize {
                model[i].push(Cell::new(' '));
            }
        }

        UiModel {
            columns: columns as usize,
            rows: rows as usize,
            cur_row: 0,
            cur_col: 0,
            model: model,
            top: 0,
            bot: (rows - 1) as usize,
            left: 0,
            right: (columns - 1) as usize,
        }
    }

    pub fn model(&self) -> &Vec<Vec<Cell>> {
        &self.model
    }

    pub fn set_cursor(&mut self, row: u64, col: u64) -> ModelRect {
        let mut changed_region = ModelRect::point(self.cur_row, self.cur_col);

        self.cur_row = row as usize;
        self.cur_col = col as usize;

        changed_region.join(&ModelRect::point(self.cur_row, self.cur_col));

        changed_region

    }

    pub fn get_cursor(&self) -> (usize, usize) {
        (self.cur_row, self.cur_col)
    }

    pub fn put(&mut self, text: &str, attrs: Option<&Attrs>) -> ModelRect {
        let mut cell = &mut self.model[self.cur_row][self.cur_col];
        let changed_region = ModelRect::point(self.cur_row, self.cur_col);

        cell.ch = text.chars().last().unwrap_or(' ');
        cell.attrs = attrs.map(Attrs::clone).unwrap_or_else(|| Attrs::new());
        cell.attrs.double_width = text.len() == 0;
        self.cur_col += 1;

        changed_region
    }

    pub fn set_scroll_region(&mut self, top: u64, bot: u64, left: u64, right: u64) {
        self.top = top as usize;
        self.bot = bot as usize;
        self.left = left as usize;
        self.right = right as usize;
    }

    #[inline]
    fn copy_row(&mut self, row: usize, offset: usize, left: usize, right: usize) {
        for col in left..right + 1 {
            let from_row = row + offset;
            let from_cell = self.model[from_row][col].clone();
            self.model[row][col] = from_cell;
        }
    }

    pub fn scroll(&mut self, count: usize) -> ModelRect {
        let (top, bot, left, right) = (self.top, self.bot, self.left, self.right);

        if count > 0 {
            for row in top..(bot - count + 1) {
                self.copy_row(row, count, left, right);
            }
        } else {
            for row in ((top - count)..(bot + 1)).rev() {
                self.copy_row(row, count, left, right);
            }
        }

        if count > 0 {
            self.clear_region((bot - count + 1), bot, left, right);
        } else {
            self.clear_region(top, (top - count - 1), left, right);
        }

        ModelRect::new(top, bot, left ,right)
    }

    pub fn clear(&mut self) -> ModelRect {
        let (rows, columns) = (self.rows, self.columns);
        self.clear_region(0, rows - 1, 0, columns - 1);

        ModelRect::new(0, 0, rows -1, columns -1)
    }

    pub fn eol_clear(&mut self) -> ModelRect {
        let (cur_row, cur_col, columns) = (self.cur_row, self.cur_col, self.columns);
        self.clear_region(cur_row, cur_row, cur_col, columns - 1);

        ModelRect::new(cur_row, cur_col, cur_col, columns -1)
    }

    fn clear_region(&mut self, top: usize, bot: usize, left: usize, right: usize) {
        for row in &mut self.model[top..bot + 1] {
            for cell in &mut row[left..right + 1] {
                cell.clear();
            }
        }
    }
}

pub struct ModelRect {
    top: usize,
    bot: usize,
    left: usize,
    right: usize,
}

impl ModelRect {
    pub fn new(top: usize, bot: usize, left: usize, right: usize) -> ModelRect {
        ModelRect {
            top: top,
            bot: bot,
            left: left,
            right: right,
        }
    }

    pub fn point(x: usize, y: usize) -> ModelRect {
        ModelRect {
            top: x,
            bot: x,
            left: y,
            right: y,
        }
    }

    pub fn join(&mut self, rect: &ModelRect) {
        self.top = if self.top < rect.top {
            self.top
        } else {
            rect.top
        };
        self.left = if self.left < rect.left {
            self.left
        } else {
            rect.left
        };

        self.bot = if self.bot > rect.bot {
            self.bot
        } else {
            rect.bot
        };
        self.right = if self.right > rect.right {
            self.right
        } else {
            rect.right
        };
    }

    pub fn to_area(&self, line_height: i32, char_width: i32) -> (i32, i32, i32, i32) {
        let y = self.top as i32 * line_height;
        let x = self.left as i32 * char_width;
        (x, y, self.right as i32 * char_width - x, self.bot as i32 * line_height - y)
    }
}