mod cell;
mod line;
mod item;
mod model_rect;
mod model_layout;

pub use self::cell::{Cell, Attrs};
pub use self::line::{Line, StyledLine};
pub use self::item::Item;
pub use self::model_rect::{ModelRect, ModelRectVec};
pub use self::model_layout::ModelLayout;


pub struct UiModel {
    pub columns: usize,
    pub rows: usize,
    cur_row: usize,
    cur_col: usize,
    model: Box<[Line]>,
    top: usize,
    bot: usize,
    left: usize,
    right: usize,
}

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

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

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

    #[inline]
    pub fn model(&self) -> &[Line] {
        &self.model
    }

    #[inline]
    pub fn model_mut(&mut self) -> &mut [Line] {
        &mut self.model
    }

    pub fn cur_point(&self) -> ModelRect {
        ModelRect::point(self.cur_col, self.cur_row)
    }

    pub fn set_cursor(&mut self, row: usize, col: usize) -> ModelRectVec {
        // it is possible in some cases that cursor moved out of visible rect
        // see https://github.com/daa84/neovim-gtk/issues/20
        if row >= self.model.len() || col >= self.model[row].line.len() {
            return ModelRectVec::empty();
        }

        let mut changed_region = ModelRectVec::new(self.cur_point());

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

        changed_region.join(&self.cur_point());

        changed_region

    }

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

    pub fn put(&mut self, ch: Option<String>, double_width: bool, attrs: Option<&Attrs>) -> ModelRect {
        let mut changed_region = self.cur_point();
        let line = &mut self.model[self.cur_row];
        line.dirty_line = true;

        let cell = &mut line[self.cur_col];

        cell.ch = ch;
        cell.attrs = attrs.map(Attrs::clone).unwrap_or_else(Attrs::new);
        cell.attrs.double_width = double_width;
        cell.dirty = true;
        self.cur_col += 1;
        if self.cur_col >= self.columns {
            self.cur_col -= 1;
        }

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

        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;
    }

    /// Copy rows from 0 to to_row, col from 0 self.columns
    ///
    /// Don't do any validation!
    pub fn copy_rows(&self, target: &mut UiModel, to_row: usize) {
        for (row_idx, line) in self.model[0..to_row + 1].iter().enumerate() {
            let mut target_row = &mut target.model[row_idx];
            line.copy_to(target_row, 0, self.columns - 1);
        }
    }

    #[inline]
    fn copy_row(&mut self, target_row: i64, offset: i64, left_col: usize, right_col: usize) {
        debug_assert_ne!(0, offset);

        let from_row = (target_row + offset) as usize;

        let (left, right) = if offset > 0 {
            self.model.split_at_mut(from_row)
        } else {
            self.model.split_at_mut(target_row as usize)
        };

        let (source_row, target_row) = if offset > 0 {
            (&right[0], &mut left[target_row as usize])
        } else {
            (&left[from_row], &mut right[0])
        };

        source_row.copy_to(target_row, left_col, right_col);
    }

    pub fn scroll(&mut self, count: i64) -> ModelRect {
        let (top, bot, left, right) = (self.top as i64, self.bot as i64, 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) as usize, bot as usize, left, right);
        } else {
            self.clear_region(top as usize, (top - count - 1) as usize, left, right);
        }

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

    pub fn clear(&mut self) {
        let (rows, columns) = (self.rows, self.columns);
        self.clear_region(0, rows - 1, 0, 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_row, 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] {
            row.clear(left, right);
        }
    }

    pub fn clear_glyphs(&mut self) {
        for row in &mut self.model.iter_mut() {
            row.clear_glyphs();
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_vec_join_inside() {
        let mut list = ModelRectVec::new(ModelRect::new(0, 23, 0, 69));

        let inside = ModelRect::new(23, 23, 68, 69);

        list.join(&inside);
        assert_eq!(1, list.list.len());
    }

    #[test]
    fn test_vec_join_top() {
        let mut list = ModelRectVec::new(ModelRect::point(0, 0));

        let neighbor = ModelRect::point(1, 0);

        list.join(&neighbor);
        assert_eq!(1, list.list.len());
    }

    #[test]
    fn test_model_vec_join_right() {
        let mut list = ModelRectVec::new(ModelRect::new(23, 23, 69, 69));

        let neighbor = ModelRect::new(23, 23, 69, 70);

        list.join(&neighbor);
        assert_eq!(1, list.list.len());
    }

    #[test]
    fn test_model_vec_join_right2() {
        let mut list = ModelRectVec::new(ModelRect::new(0, 1, 0, 9));

        let neighbor = ModelRect::new(1, 1, 9, 10);

        list.join(&neighbor);
        assert_eq!(1, list.list.len());
    }

    #[test]
    fn test_model_vec_join() {
        let mut list = ModelRectVec::new(ModelRect::point(5, 5));

        let neighbor = ModelRect::point(6, 5);

        list.join(&neighbor);
        assert_eq!(1, list.list.len());
    }

    #[test]
    fn test_model_vec_no_join() {
        let mut list = ModelRectVec::new(ModelRect::point(5, 5));

        let not_neighbor = ModelRect::point(6, 6);

        list.join(&not_neighbor);
        assert_eq!(2, list.list.len());
    }

    #[test]
    fn test_cursor_area() {
        let mut model = UiModel::new(10, 20);

        model.set_cursor(1, 1);

        let rect = model.set_cursor(5, 5);

        assert_eq!(2, rect.list.len());

        assert_eq!(1, rect.list[0].top);
        assert_eq!(1, rect.list[0].left);
        assert_eq!(1, rect.list[0].bot);
        assert_eq!(1, rect.list[0].right);


        assert_eq!(5, rect.list[1].top);
        assert_eq!(5, rect.list[1].left);
        assert_eq!(5, rect.list[1].bot);
        assert_eq!(5, rect.list[1].right);
    }

    #[test]
    fn test_eol_clear_area() {
        let mut model = UiModel::new(10, 20);

        model.set_cursor(1, 2);

        let rect = model.eol_clear();

        assert_eq!(1, rect.top);
        assert_eq!(2, rect.left);
        assert_eq!(1, rect.bot);
        assert_eq!(19, rect.right);
    }

    #[test]
    fn test_put_area() {
        let mut model = UiModel::new(10, 20);

        model.set_cursor(1, 1);

        let rect = model.put(Some(" ".to_owned()), false, None);

        assert_eq!(1, rect.top);
        assert_eq!(1, rect.left);
        assert_eq!(1, rect.bot);
        assert_eq!(2, rect.right);
    }

    #[test]
    fn test_scroll_area() {
        let mut model = UiModel::new(10, 20);

        model.set_scroll_region(1, 5, 1, 5);

        let rect = model.scroll(3);

        assert_eq!(1, rect.top);
        assert_eq!(1, rect.left);
        assert_eq!(5, rect.bot);
        assert_eq!(5, rect.right);
    }
}