use crate::{
    builder::validator::multi_line_text_field_info::MultiLineTextFieldInfo,
    guihandler::gui::writeable::ModifyText, prelude::*,
};

use std::sync::{
    atomic::{AtomicU32, Ordering::SeqCst},
    Arc, Mutex,
};

use anyhow::Result;

use super::fill_type::InnerFillType;

pub struct MultiLineTextFieldBuilder {
    text_alignment: TextAlignment,
    text_ratio: f32,
    text_color: Color,
    text: Option<String>,

    line_count: u32,

    background: Option<FillTypeInfo>,
}

impl MultiLineTextFieldBuilder {
    pub fn set_text(mut self, text: impl Into<String>) -> Self {
        self.text = Some(text.into());

        self
    }

    pub fn set_ratio(mut self, ratio: f32) -> Self {
        self.text_ratio = ratio;

        self
    }

    pub fn set_text_color(mut self, text_color: impl Into<Color>) -> Self {
        self.text_color = text_color.into();

        self
    }

    pub fn set_text_alignment(mut self, text_alignment: TextAlignment) -> Self {
        self.text_alignment = text_alignment;

        self
    }

    pub fn set_line_count(mut self, line_count: u32) -> Self {
        self.line_count = line_count;

        self
    }

    pub fn set_background(mut self, background: impl Into<FillTypeInfo>) -> Self {
        self.background = Some(background.into());

        self
    }

    pub fn build(self, gui_handler: Arc<GuiHandler>) -> Result<Arc<MultiLineTextField>> {
        let base_grid = Grid::new(gui_handler.clone(), 1, self.line_count as usize, false)?;
        base_grid.set_margin(0);
        base_grid.set_padding(0);

        if let Some(background) = self.background {
            base_grid.set_background(background)?;
        }

        for i in 0..self.line_count {
            let label = Label::builder()
                .set_ratio(self.text_ratio)
                .set_text_color(self.text_color)
                .set_text_alignment(self.text_alignment)
                .build(gui_handler.clone())?;

            base_grid.attach(label, 0, i as usize, 1, 1)?;
        }

        let text = Arc::new(SplittedText::new(self.text));
        let text_changed_exec = Executable::new();
        let writeable = Writeable::new(gui_handler, text.clone(), text_changed_exec.clone())?;

        let multi_line_text_field = Arc::new(MultiLineTextField {
            grid: base_grid,

            text,
            text_changed_exec,
            writeable,
        });

        multi_line_text_field.text_changed_exec.set_callback({
            let weak_tf = Arc::downgrade(&multi_line_text_field);

            move |_text| {
                if let Some(tf) = weak_tf.upgrade() {
                    tf.update_text()?;
                }

                Ok(())
            }
        });

        multi_line_text_field.update_color_change();

        Ok(multi_line_text_field)
    }
}

struct SplittedText {
    characters_per_line: AtomicU32,
    text: Mutex<String>,
    splits: Mutex<Vec<String>>,
}

impl SplittedText {
    fn new(text: Option<String>) -> Self {
        Self {
            characters_per_line: AtomicU32::new(0),
            text: Mutex::new(text.unwrap_or_default()),
            splits: Mutex::new(Vec::new()),
        }
    }

    fn text(&self) -> String {
        self.text.lock().unwrap().clone()
    }

    fn set_characters_per_line(&self, characters_per_line: u32) {
        self.characters_per_line.store(characters_per_line, SeqCst);
    }

    fn lines(&self) -> Vec<String> {
        self.splits.lock().unwrap().clone()
    }

    fn update_text(&self) -> Result<()> {
        let text = self.text.lock().unwrap();
        let splits = text.split(' ');
        let character_count = self.characters_per_line.load(SeqCst) as usize;

        let mut current_line = String::new();
        let mut lines = Vec::new();

        for split in splits {
            let current_len = current_line.len();
            let next_len = split.len() + 1;

            if (current_len + next_len) <= character_count {
                if current_line.is_empty() {
                    current_line = split.to_string();
                } else {
                    current_line += &format!(" {}", split);
                }
            } else {
                lines.push(current_line);
                current_line = split.to_string();
            }
        }

        if !current_line.is_empty() {
            lines.push(current_line);
        }

        *self.splits.lock().unwrap() = lines.clone();

        Ok(())
    }
}

impl ModifyText for SplittedText {
    fn set_text(&self, text: String) -> Result<()> {
        *self.text.lock().unwrap() = text;

        self.update_text()
    }

    fn add_letter(&self, letter: char) -> Result<String> {
        *self.text.lock().unwrap() += &format!("{}", letter);

        self.update_text()?;

        Ok(self.text.lock().unwrap().clone())
    }

    fn remove_last(&self) -> Result<Option<String>> {
        self.text.lock().unwrap().pop();

        self.update_text()?;

        let text = self.text.lock().unwrap().clone();
        Ok(if text.is_empty() { None } else { Some(text) })
    }
}

pub struct MultiLineTextField {
    grid: Arc<Grid>,

    text: Arc<SplittedText>,
    text_changed_exec: Arc<Executable<Option<String>>>,
    writeable: Arc<Writeable>,
}

impl MultiLineTextField {
    pub fn builder() -> MultiLineTextFieldBuilder {
        MultiLineTextFieldBuilder {
            text_alignment: TextAlignment::Center,
            text_ratio: 0.7,
            text_color: Color::Black,
            text: None,

            line_count: 1,

            background: None,
        }
    }

    pub fn set_text(&self, text: impl ToString) -> Result<()> {
        self.text.set_text(text.to_string())
    }

    fn update_text(&self) -> Result<()> {
        let lines = self.text.lines();

        self.iter_label(|label, y| {
            if y < lines.len() {
                label.set_text(&lines[y])?;
            } else {
                label.set_text("")?;
            }

            Ok(())
        })
    }

    fn update_color_change(self: &Arc<Self>) {
        if let Some(background) = &*self.grid.background() {
            if let InnerFillType::Color(colorable) = &background.inner {
                let normal_color = colorable.color();
                let focus_color = normal_color * 1.4;

                let weak_self = Arc::downgrade(self);

                self.writeable.set_activation_changed(move |active| {
                    if let Some(me) = weak_self.upgrade() {
                        if active {
                            me.grid.set_background(focus_color)?;
                        } else {
                            me.grid.set_background(normal_color)?;
                        }
                    }

                    Ok(())
                });
            }
        }
    }

    pub fn text(&self) -> String {
        self.text.text()
    }

    pub fn set_text_color(&self, text_color: Color) -> Result<()> {
        self.iter_label(|label, _| label.set_text_color(text_color))
    }

    pub fn set_alignment(&self, alignment: TextAlignment) -> Result<()> {
        self.iter_label(|label, _| label.set_alignment(alignment))
    }

    pub fn set_text_ratio(&self, ratio: f32) -> Result<()> {
        self.iter_label(|label, _| label.set_text_ratio(ratio))
    }

    pub fn set_background(self: &Arc<Self>, background: impl Into<FillTypeInfo>) -> Result<()> {
        self.grid.set_background(background)?;
        self.update_color_change();

        Ok(())
    }

    pub fn focus_input(&self) -> Result<()> {
        self.writeable.set_active()
    }

    pub fn try_from(
        multi_line_text_field_info: &MultiLineTextFieldInfo,
        gui_handler: &Arc<GuiHandler>,
    ) -> Result<Arc<Self>> {
        let text = multi_line_text_field_info.text.read().unwrap().clone();
        let color = multi_line_text_field_info.text_color;

        let mut multi_line_text_field_builder = MultiLineTextField::builder()
            .set_text_color(color)
            .set_text_alignment(multi_line_text_field_info.text_alignment)
            .set_line_count(multi_line_text_field_info.line_count.get()?);

        if let Some(background_type) = &multi_line_text_field_info.background_type {
            multi_line_text_field_builder =
                multi_line_text_field_builder.set_background(background_type.clone());
        }

        if let Some(ratio) = multi_line_text_field_info.text_ratio {
            multi_line_text_field_builder = multi_line_text_field_builder.set_ratio(ratio);
        }

        if !text.is_empty() {
            multi_line_text_field_builder = multi_line_text_field_builder.set_text(text);
        }

        multi_line_text_field_builder.build(gui_handler.clone())
    }

    fn iter_label<F>(&self, f: F) -> Result<()>
    where
        F: Fn(&Label, usize) -> Result<()>,
    {
        for y in 0..self.grid.dimensions().1 {
            let child = self.grid.child_at(0, y)?.unwrap();
            let gui_element = child.downcast().unwrap();
            let label = gui_element.label().unwrap();

            f(label, y)?;
        }

        Ok(())
    }
}

impl GuiElementTraits for MultiLineTextField {
    fn gridable(&self) -> Option<&dyn Gridable> {
        Some(self)
    }

    fn visibility(&self) -> Option<&dyn Visibility> {
        Some(self)
    }

    fn downcast<'a>(&'a self) -> Option<GuiElement<'a>> {
        Some(GuiElement::MultiLineTextField(self))
    }
}

impl Visibility for MultiLineTextField {
    fn visible(&self) -> bool {
        self.grid.visible()
    }

    fn set_visibility(&self, visibility: bool) -> Result<()> {
        if visibility != self.visible() {
            if visibility {
                self.writeable.add()?;
            } else {
                self.writeable.delete()?;
            }
        }

        self.grid.set_visibility(visibility)
    }
}

impl Gridable for MultiLineTextField {
    fn set_frame(
        &self,
        x: i32,
        y: i32,
        w: u32,
        h: u32,
        vert_align: VerticalAlign,
        hori_align: HorizontalAlign,
    ) -> Result<()> {
        self.grid.set_frame(x, y, w, h, vert_align, hori_align)?;

        if let Some(child) = self.grid.child_at(0, 0)? {
            let gui_element = child.downcast().unwrap();
            let label = gui_element.label().unwrap();

            let left = label.framable.left();
            let right = label.framable.right();
            let top = label.framable.top();
            let bottom = label.framable.bottom();

            let width = right - left;
            let height = bottom - top;

            let text_ratio = label.text_ratio();

            let text_size = height as f32 * text_ratio;
            let max_letter_count = (width as f32 / (text_size / 2.0)).floor();

            self.text.set_characters_per_line(max_letter_count as u32);

            self.update_text()?;
        }

        Ok(())
    }

    fn selectable(&self) -> Option<&Arc<Selectable>> {
        None
    }

    fn type_name(&self) -> &str {
        "MultiLineLabel"
    }

    fn set_layer(&self, layer: i32) -> Result<()> {
        self.writeable.set_ui_layer(layer);
        self.grid.set_layer(layer)
    }
}

impl Drop for MultiLineTextField {
    fn drop(&mut self) {
        if self.visible() {
            self.writeable.delete().unwrap();
        }
    }
}