use crate::{
    msg::{Args, CallbackId, Msg, OutputName, Request, RequestResponse},
    request, send_msg,
    tag::{Tag, TagHandle},
    CALLBACK_VEC,
};

/// Output management.
pub struct Output;

impl Output {
    /// Get an [`OutputHandle`] by its name.
    ///
    /// `name` is the name of the port the output is plugged in to.
    /// This is something like `HDMI-1` or `eDP-0`.
    pub fn get_by_name(&self, name: &str) -> Option<OutputHandle> {
        let RequestResponse::Outputs { output_names } = request(Request::GetOutputs) else {
            unreachable!()
        };

        output_names
            .into_iter()
            .find(|s| s == name)
            .map(|s| OutputHandle(OutputName(s)))
    }

    /// Get a handle to all connected outputs.
    pub fn get_all(&self) -> impl Iterator<Item = OutputHandle> {
        let RequestResponse::Outputs { output_names } = request(Request::GetOutputs) else {
            unreachable!()
        };

        output_names
            .into_iter()
            .map(|name| OutputHandle(OutputName(name)))
    }

    /// Get the currently focused output.
    ///
    /// This is currently defined as the one with the cursor on it.
    pub fn get_focused(&self) -> Option<OutputHandle> {
        let RequestResponse::Outputs { output_names } = request(Request::GetOutputs) else {
            unreachable!()
        };

        output_names
            .into_iter()
            .map(|s| OutputHandle(OutputName(s)))
            .find(|op| op.properties().focused == Some(true))
    }

    pub fn connect_for_all<F>(&self, mut func: F)
    where
        F: FnMut(OutputHandle) + Send + 'static,
    {
        let args_callback = move |args: Option<Args>| {
            if let Some(Args::ConnectForAllOutputs { output_name }) = args {
                func(OutputHandle(OutputName(output_name)));
            }
        };

        let mut callback_vec = CALLBACK_VEC.lock().unwrap();
        let len = callback_vec.len();
        callback_vec.push(Box::new(args_callback));

        let msg = Msg::ConnectForAllOutputs {
            callback_id: CallbackId(len as u32),
        };

        send_msg(msg).unwrap();
    }
}

/// An output handle.
///
/// This is a handle to one of your monitors.
/// It serves to make it easier to deal with them, defining methods for getting properties and
/// helpers for things like positioning multiple monitors.
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct OutputHandle(pub OutputName);

/// Properties of an output.
pub struct OutputProperties {
    /// The make.
    pub make: Option<String>,
    /// The model.
    ///
    /// This is something like `27GL850` or whatever gibberish monitor manufacturers name their
    /// displays.
    pub model: Option<String>,
    /// The location of the output in the global space.
    pub loc: Option<(i32, i32)>,
    /// The resolution of the output in pixels, where `res.0` is the width and `res.1` is the
    /// height.
    pub res: Option<(i32, i32)>,
    /// The refresh rate of the output in millihertz.
    ///
    /// For example, 60Hz is returned as 60000.
    pub refresh_rate: Option<i32>,
    /// The physical size of the output in millimeters.
    pub physical_size: Option<(i32, i32)>,
    /// Whether or not the output is focused.
    pub focused: Option<bool>,
    /// The tags on this output.
    pub tags: Vec<TagHandle>,
}

impl OutputHandle {
    // TODO: Make OutputProperties an option, make non null fields not options
    /// Get all properties of this output.
    pub fn properties(&self) -> OutputProperties {
        let RequestResponse::OutputProps {
            make,
            model,
            loc,
            res,
            refresh_rate,
            physical_size,
            focused,
            tag_ids,
        } = request(Request::GetOutputProps {
            output_name: self.0 .0.clone(),
        })
        else {
            unreachable!()
        };

        OutputProperties {
            make,
            model,
            loc,
            res,
            refresh_rate,
            physical_size,
            focused,
            tags: tag_ids
                .unwrap_or(vec![])
                .into_iter()
                .map(TagHandle)
                .collect(),
        }
    }

    pub fn add_tags(&self, names: &[&str]) {
        Tag.add(self, names);
    }

    pub fn set_loc(&self, x: Option<i32>, y: Option<i32>) {
        let msg = Msg::SetOutputLocation {
            output_name: self.0.clone(),
            x,
            y,
        };

        send_msg(msg).unwrap();
    }

    pub fn set_loc_right_of(&self, other: &OutputHandle, alignment: AlignmentVertical) {
        self.set_loc_horizontal(other, LeftOrRight::Right, alignment);
    }

    pub fn set_loc_left_of(&self, other: &OutputHandle, alignment: AlignmentVertical) {
        self.set_loc_horizontal(other, LeftOrRight::Left, alignment);
    }

    pub fn set_loc_top_of(&self, other: &OutputHandle, alignment: AlignmentHorizontal) {
        self.set_loc_vertical(other, TopOrBottom::Top, alignment);
    }

    pub fn set_loc_bottom_of(&self, other: &OutputHandle, alignment: AlignmentHorizontal) {
        self.set_loc_vertical(other, TopOrBottom::Bottom, alignment);
    }

    fn set_loc_horizontal(
        &self,
        other: &OutputHandle,
        left_or_right: LeftOrRight,
        alignment: AlignmentVertical,
    ) {
        let op1_props = self.properties();
        let op2_props = other.properties();

        let (Some(_self_loc), Some(self_res), Some(other_loc), Some(other_res)) =
            (op1_props.loc, op1_props.res, op2_props.loc, op2_props.res)
        else {
            return;
        };

        let x = match left_or_right {
            LeftOrRight::Left => other_loc.0 - self_res.0,
            LeftOrRight::Right => other_loc.0 + self_res.0,
        };

        let y = match alignment {
            AlignmentVertical::Top => other_loc.1,
            AlignmentVertical::Center => other_loc.1 + (other_res.1 - self_res.1) / 2,
            AlignmentVertical::Bottom => other_loc.1 + (other_res.1 - self_res.1),
        };

        self.set_loc(Some(x), Some(y));
    }

    fn set_loc_vertical(
        &self,
        other: &OutputHandle,
        top_or_bottom: TopOrBottom,
        alignment: AlignmentHorizontal,
    ) {
        let op1_props = self.properties();
        let op2_props = other.properties();

        let (Some(_self_loc), Some(self_res), Some(other_loc), Some(other_res)) =
            (op1_props.loc, op1_props.res, op2_props.loc, op2_props.res)
        else {
            return;
        };

        let y = match top_or_bottom {
            TopOrBottom::Top => other_loc.1 - self_res.1,
            TopOrBottom::Bottom => other_loc.1 + other_res.1,
        };

        let x = match alignment {
            AlignmentHorizontal::Left => other_loc.0,
            AlignmentHorizontal::Center => other_loc.0 + (other_res.0 - self_res.0) / 2,
            AlignmentHorizontal::Right => other_loc.0 + (other_res.0 - self_res.0),
        };

        self.set_loc(Some(x), Some(y));
    }
}

enum TopOrBottom {
    Top,
    Bottom,
}

enum LeftOrRight {
    Left,
    Right,
}

pub enum AlignmentHorizontal {
    Left,
    Center,
    Right,
}

pub enum AlignmentVertical {
    Top,
    Center,
    Bottom,
}