use crate::rect::Rect;
use crate::render::Renderer;
use crate::tree::{FoundNode, Node, NodeId, WorkspaceNode};
use crate::utils::clonecell::CloneCell;
use crate::utils::linkedlist::{LinkedList, LinkedNode, NodeRef};
use crate::{NumCell, State};
use ahash::AHashMap;
use std::cell::{Cell, RefCell};
use std::rc::Rc;

#[allow(dead_code)]
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum ContainerSplit {
    Horizontal,
    Vertical,
}

#[allow(dead_code)]
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum ContainerFocus {
    None,
    Child,
    Yes,
}

tree_id!(ContainerNodeId);

pub const CONTAINER_TITLE_HEIGHT: i32 = 18;
pub const CONTAINER_BORDER: i32 = 2;

pub struct ContainerNode {
    pub id: ContainerNodeId,
    pub parent: CloneCell<Rc<dyn Node>>,
    pub split: Cell<ContainerSplit>,
    pub mono_child: CloneCell<Option<NodeRef<ContainerChild>>>,
    pub mono_body: Cell<Rect>,
    pub mono_content: Cell<Rect>,
    pub abs_x1: Cell<i32>,
    pub abs_y1: Cell<i32>,
    pub width: Cell<i32>,
    pub height: Cell<i32>,
    pub content_width: Cell<i32>,
    pub content_height: Cell<i32>,
    num_children: NumCell<usize>,
    pub children: LinkedList<ContainerChild>,
    child_nodes: RefCell<AHashMap<NodeId, LinkedNode<ContainerChild>>>,
}

pub struct ContainerChild {
    pub node: Rc<dyn Node>,
    pub body: Cell<Rect>,
    pub content: Cell<Rect>,
    factor: Cell<f64>,
    pub focus: Cell<ContainerFocus>,
}

impl ContainerChild {
    fn position_content(&self) {
        let mut content = self.content.get();
        let body = self.body.get();
        let width = content.width();
        let height = content.height();
        // let x1 = body.x1() + (body.width() - width) / 2;
        // let y1 = body.y1() + (body.height() - height) / 2;
        let x1 = body.x1();
        let y1 = body.y1();
        content = Rect::new_sized(x1, y1, width, height).unwrap();
        // log::debug!("body: {:?}", body);
        // log::debug!("content: {:?}", content);
        self.content.set(content);
    }
}

impl ContainerNode {
    pub fn new(state: &State, parent: Rc<dyn Node>, child: Rc<dyn Node>) -> Self {
        let children = LinkedList::new();
        let mut child_nodes = AHashMap::new();
        child_nodes.insert(
            child.id(),
            children.add_last(ContainerChild {
                node: child,
                body: Cell::new(Default::default()),
                content: Cell::new(Default::default()),
                factor: Cell::new(1.0),
                focus: Cell::new(ContainerFocus::None),
            }),
        );
        Self {
            id: state.node_ids.next(),
            parent: CloneCell::new(parent),
            split: Cell::new(ContainerSplit::Horizontal),
            mono_child: CloneCell::new(None),
            mono_body: Cell::new(Default::default()),
            mono_content: Cell::new(Default::default()),
            abs_x1: Cell::new(0),
            abs_y1: Cell::new(0),
            width: Cell::new(0),
            height: Cell::new(0),
            content_width: Cell::new(0),
            content_height: Cell::new(0),
            num_children: NumCell::new(1),
            children,
            child_nodes: RefCell::new(child_nodes),
        }
    }

    pub fn num_children(&self) -> usize {
        self.num_children.get()
    }

    pub fn append_child(self: &Rc<Self>, new: Rc<dyn Node>) {
        if let Some(child) = self.children.last() {
            self.add_child_after_(&child, new);
            return;
        }
        log::error!("Tried to add a child to a container but container is empty");
    }

    pub fn add_child_after(self: &Rc<Self>, prev: &dyn Node, new: Rc<dyn Node>) {
        let node = self
            .child_nodes
            .borrow()
            .get(&prev.id())
            .map(|n| n.to_ref());
        if let Some(node) = node {
            self.add_child_after_(&node, new);
            return;
        }
        log::error!(
            "Tried to add a child to a container but the preceding node is not in the container"
        );
    }

    fn add_child_after_(self: &Rc<Self>, prev: &NodeRef<ContainerChild>, new: Rc<dyn Node>) {
        {
            let mut links = self.child_nodes.borrow_mut();
            if links.contains_key(&new.id()) {
                log::error!("Tried to add a child to a container that already contains the child");
                return;
            }
            links.insert(
                new.id(),
                prev.append(ContainerChild {
                    node: new.clone(),
                    body: Default::default(),
                    content: Default::default(),
                    factor: Cell::new(0.0),
                    focus: Cell::new(ContainerFocus::None),
                }),
            );
        }
        let num_children = self.num_children.fetch_add(1) + 1;
        self.update_content_size();
        let new_child_factor = 1.0 / num_children as f64;
        let mut sum_factors = 0.0;
        for child in self.children.iter() {
            let factor = if Rc::ptr_eq(&child.node, &new) {
                new_child_factor
            } else {
                child.factor.get() * (1.0 - new_child_factor)
            };
            child.factor.set(factor);
            sum_factors += factor;
        }
        self.apply_factors(sum_factors);
    }

    fn apply_factors(&self, sum_factors: f64) {
        let split = self.split.get();
        let (content_size, other_content_size) = match split {
            ContainerSplit::Horizontal => (self.content_width.get(), self.content_height.get()),
            ContainerSplit::Vertical => (self.content_height.get(), self.content_width.get()),
        };
        let num_children = self.num_children.get();
        let mut pos = 0;
        let mut remaining_content_size = content_size;
        for child in self.children.iter() {
            let factor = child.factor.get() / sum_factors;
            child.factor.set(factor);
            let mut body_size = (content_size as f64 * factor).round() as i32;
            body_size = body_size.min(remaining_content_size);
            remaining_content_size -= body_size;
            let (x1, y1, width, height) = match split {
                ContainerSplit::Horizontal => {
                    (pos, CONTAINER_TITLE_HEIGHT, body_size, other_content_size)
                }
                _ => (0, pos, other_content_size, body_size),
            };
            let body = Rect::new_sized(x1, y1, width, height).unwrap();
            child.body.set(body);
            pos += body_size + CONTAINER_BORDER;
            if split == ContainerSplit::Vertical {
                pos += CONTAINER_TITLE_HEIGHT;
            }
        }
        if remaining_content_size > 0 {
            let size_per = remaining_content_size / num_children as i32;
            let mut rem = remaining_content_size % num_children as i32;
            pos = 0;
            for child in self.children.iter() {
                let mut body = child.body.get();
                let mut add = size_per;
                if rem > 0 {
                    rem -= 1;
                    add += 1;
                }
                let (x1, y1, width, height, size) = match split {
                    ContainerSplit::Horizontal => {
                        let width = body.width() + add;
                        (
                            pos,
                            CONTAINER_TITLE_HEIGHT,
                            width,
                            other_content_size,
                            width,
                        )
                    }
                    _ => {
                        let height = body.height() + add;
                        (0, pos, other_content_size, height, height)
                    }
                };
                body = Rect::new_sized(x1, y1, width, height).unwrap();
                child.body.set(body);
                pos += size + CONTAINER_BORDER;
                if split == ContainerSplit::Vertical {
                    pos += CONTAINER_TITLE_HEIGHT;
                }
            }
        }
        for child in self.children.iter() {
            let body = child.body.get().move_(self.abs_x1.get(), self.abs_y1.get());
            child.node.clone().change_extents(&body);
            child.position_content();
        }
    }

    fn update_content_size(&self) {
        let nc = self.num_children.get();
        match self.split.get() {
            ContainerSplit::Horizontal => {
                let new_content_size = self
                    .width
                    .get()
                    .saturating_sub((nc - 1) as i32 * CONTAINER_BORDER);
                self.content_width.set(new_content_size);
                self.content_height
                    .set(self.height.get().saturating_sub(CONTAINER_TITLE_HEIGHT));
            }
            ContainerSplit::Vertical => {
                let new_content_size = self.height.get().saturating_sub(
                    CONTAINER_TITLE_HEIGHT
                        + (nc - 1) as i32 * (CONTAINER_BORDER + CONTAINER_TITLE_HEIGHT),
                );
                self.content_height.set(new_content_size);
                self.content_width.set(self.width.get());
            }
        }
    }
}

impl Node for ContainerNode {
    fn id(&self) -> NodeId {
        self.id.into()
    }

    fn clear(&self) {
        let mut cn = self.child_nodes.borrow_mut();
        for (_, n) in cn.drain() {
            n.node.clear();
        }
    }

    fn find_child_at(&self, x: i32, y: i32) -> Option<FoundNode> {
        if let Some(child) = self.mono_child.get() {
            if self.mono_body.get().contains(x, y) {
                let content = self.mono_content.get();
                let (x, y) = content.translate(x, y);
                return Some(FoundNode {
                    node: child.node.clone(),
                    x,
                    y,
                    contained: content.contains(x, y),
                });
            }
            return None;
        }
        for child in self.children.iter() {
            if child.body.get().contains(x, y) {
                let content = child.content.get();
                let (x, y) = content.translate(x, y);
                return Some(FoundNode {
                    node: child.node.clone(),
                    x,
                    y,
                    contained: content.contains(x, y),
                });
            }
        }
        None
    }

    fn remove_child(&self, child: &dyn Node) {
        let node = match self.child_nodes.borrow_mut().remove(&child.id()) {
            Some(c) => c.to_ref(),
            None => return,
        };
        let num_children = self.num_children.fetch_sub(1) - 1;
        if num_children == 0 {
            self.parent.get().remove_child(self);
            return;
        }
        self.update_content_size();
        let rem = 1.0 - node.factor.get();
        let mut sum = 0.0;
        if rem <= 0.0 {
            let factor = 1.0 / num_children as f64;
            for child in self.children.iter() {
                child.factor.set(factor)
            }
            sum = 1.0;
        } else {
            for child in self.children.iter() {
                let factor = child.factor.get() / rem;
                child.factor.set(factor);
                sum += factor;
            }
        }
        self.apply_factors(sum);
    }

    fn child_size_changed(&self, child: &dyn Node, width: i32, height: i32) {
        log::info!("child size changed {}x{}", width, height);
        let cn = self.child_nodes.borrow();
        if let Some(node) = cn.get(&child.id()) {
            let rect = Rect::new(0, 0, width, height).unwrap();
            node.content.set(rect);
            node.position_content();
        }
    }

    fn render(&self, renderer: &mut Renderer, x: i32, y: i32) {
        renderer.render_container(self, x, y);
    }

    fn into_container(self: Rc<Self>) -> Option<Rc<ContainerNode>> {
        Some(self)
    }

    fn get_workspace(self: Rc<Self>) -> Option<Rc<WorkspaceNode>> {
        self.parent.get().get_workspace()
    }

    fn change_extents(self: Rc<Self>, rect: &Rect) {
        self.abs_x1.set(rect.x1());
        self.abs_y1.set(rect.y1());
        let mut size_changed = false;
        size_changed |= self.width.replace(rect.width()) != rect.width();
        size_changed |= self.height.replace(rect.height()) != rect.height();
        if size_changed {
            self.update_content_size();
            self.apply_factors(1.0);
        } else {
            for child in self.children.iter() {
                let body = child.body.get().move_(self.abs_x1.get(), self.abs_y1.get());
                child.node.clone().change_extents(&body);
            }
        }
    }
}