mod events;
mod keystroke;
#[cfg(target_os = "macos")]
mod mac;
#[cfg(any(test, feature = "test"))]
mod test;

use crate::{
    AnyWindowHandle, Bounds, DevicePixels, Font, FontId, FontMetrics, GlyphId, Pixels, Point,
    RenderGlyphParams, RenderSvgParams, Result, Scene, ShapedLine, SharedString, Size,
};
use anyhow::anyhow;
use async_task::Runnable;
use futures::channel::oneshot;
use seahash::SeaHasher;
use serde::{Deserialize, Serialize};
use std::ffi::c_void;
use std::hash::{Hash, Hasher};
use std::{
    any::Any,
    fmt::{self, Debug, Display},
    ops::Range,
    path::{Path, PathBuf},
    rc::Rc,
    str::FromStr,
    sync::Arc,
};
use uuid::Uuid;

pub use events::*;
pub use keystroke::*;
#[cfg(target_os = "macos")]
pub use mac::*;
#[cfg(any(test, feature = "test"))]
pub use test::*;
pub use time::UtcOffset;

#[cfg(target_os = "macos")]
pub(crate) fn current_platform() -> Arc<dyn Platform> {
    Arc::new(MacPlatform::new())
}

pub trait Platform: 'static {
    fn dispatcher(&self) -> Arc<dyn PlatformDispatcher>;
    fn text_system(&self) -> Arc<dyn PlatformTextSystem>;

    fn run(&self, on_finish_launching: Box<dyn 'static + FnOnce()>);
    fn quit(&self);
    fn restart(&self);
    fn activate(&self, ignoring_other_apps: bool);
    fn hide(&self);
    fn hide_other_apps(&self);
    fn unhide_other_apps(&self);

    fn screens(&self) -> Vec<Rc<dyn PlatformScreen>>;
    fn screen_by_id(&self, id: ScreenId) -> Option<Rc<dyn PlatformScreen>>;
    fn main_window(&self) -> Option<AnyWindowHandle>;
    fn open_window(
        &self,
        handle: AnyWindowHandle,
        options: WindowOptions,
    ) -> Box<dyn PlatformWindow>;
    // fn add_status_item(&self, _handle: AnyWindowHandle) -> Box<dyn PlatformWindow>;

    fn open_url(&self, url: &str);
    fn on_open_urls(&self, callback: Box<dyn FnMut(Vec<String>)>);
    fn prompt_for_paths(
        &self,
        options: PathPromptOptions,
    ) -> oneshot::Receiver<Option<Vec<PathBuf>>>;
    fn prompt_for_new_path(&self, directory: &Path) -> oneshot::Receiver<Option<PathBuf>>;
    fn reveal_path(&self, path: &Path);

    fn on_become_active(&self, callback: Box<dyn FnMut()>);
    fn on_resign_active(&self, callback: Box<dyn FnMut()>);
    fn on_quit(&self, callback: Box<dyn FnMut()>);
    fn on_reopen(&self, callback: Box<dyn FnMut()>);
    fn on_event(&self, callback: Box<dyn FnMut(Event) -> bool>);

    fn os_name(&self) -> &'static str;
    fn os_version(&self) -> Result<SemanticVersion>;
    fn app_version(&self) -> Result<SemanticVersion>;
    fn app_path(&self) -> Result<PathBuf>;
    fn local_timezone(&self) -> UtcOffset;
    fn path_for_auxiliary_executable(&self, name: &str) -> Result<PathBuf>;

    fn set_cursor_style(&self, style: CursorStyle);
    fn should_auto_hide_scrollbars(&self) -> bool;

    fn write_to_clipboard(&self, item: ClipboardItem);
    fn read_from_clipboard(&self) -> Option<ClipboardItem>;

    fn write_credentials(&self, url: &str, username: &str, password: &[u8]) -> Result<()>;
    fn read_credentials(&self, url: &str) -> Result<Option<(String, Vec<u8>)>>;
    fn delete_credentials(&self, url: &str) -> Result<()>;
}

pub trait PlatformScreen: Debug {
    fn id(&self) -> Option<ScreenId>;
    fn handle(&self) -> PlatformScreenHandle;
    fn as_any(&self) -> &dyn Any;
    fn bounds(&self) -> Bounds<Pixels>;
    fn content_bounds(&self) -> Bounds<Pixels>;
}

pub struct PlatformScreenHandle(pub *mut c_void);

impl Debug for PlatformScreenHandle {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "PlatformScreenHandle({:p})", self.0)
    }
}

unsafe impl Send for PlatformScreenHandle {}

pub trait PlatformWindow {
    fn bounds(&self) -> WindowBounds;
    fn content_size(&self) -> Size<Pixels>;
    fn scale_factor(&self) -> f32;
    fn titlebar_height(&self) -> Pixels;
    fn appearance(&self) -> WindowAppearance;
    fn screen(&self) -> Rc<dyn PlatformScreen>;
    fn mouse_position(&self) -> Point<Pixels>;
    fn as_any_mut(&mut self) -> &mut dyn Any;
    fn set_input_handler(&mut self, input_handler: Box<dyn PlatformInputHandler>);
    fn prompt(
        &self,
        level: WindowPromptLevel,
        msg: &str,
        answers: &[&str],
    ) -> oneshot::Receiver<usize>;
    fn activate(&self);
    fn set_title(&mut self, title: &str);
    fn set_edited(&mut self, edited: bool);
    fn show_character_palette(&self);
    fn minimize(&self);
    fn zoom(&self);
    fn toggle_full_screen(&self);
    fn on_event(&self, callback: Box<dyn FnMut(Event) -> bool>);
    fn on_active_status_change(&self, callback: Box<dyn FnMut(bool)>);
    fn on_resize(&self, callback: Box<dyn FnMut(Size<Pixels>, f32)>);
    fn on_fullscreen(&self, callback: Box<dyn FnMut(bool)>);
    fn on_moved(&self, callback: Box<dyn FnMut()>);
    fn on_should_close(&self, callback: Box<dyn FnMut() -> bool>);
    fn on_close(&self, callback: Box<dyn FnOnce()>);
    fn on_appearance_changed(&self, callback: Box<dyn FnMut()>);
    fn is_topmost_for_position(&self, position: Point<Pixels>) -> bool;
    fn draw(&self, scene: Scene);

    fn monochrome_sprite_atlas(&self) -> Arc<dyn PlatformAtlas>;
    fn polychrome_sprite_atlas(&self) -> Arc<dyn PlatformAtlas>;
}

pub trait PlatformDispatcher: Send + Sync {
    fn is_main_thread(&self) -> bool;
    fn run_on_main_thread(&self, task: Runnable);
}

pub trait PlatformTextSystem: Send + Sync {
    fn add_fonts(&self, fonts: &[Arc<Vec<u8>>]) -> Result<()>;
    fn all_font_families(&self) -> Vec<String>;
    fn font_id(&self, descriptor: &Font) -> Result<FontId>;
    fn font_metrics(&self, font_id: FontId) -> FontMetrics;
    fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>>;
    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>>;
    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId>;
    fn glyph_raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>>;
    fn rasterize_glyph(&self, params: &RenderGlyphParams) -> Result<(Size<DevicePixels>, Vec<u8>)>;
    fn layout_line(&self, text: &str, font_size: Pixels, runs: &[(usize, FontId)]) -> ShapedLine;
    fn wrap_line(
        &self,
        text: &str,
        font_id: FontId,
        font_size: Pixels,
        width: Pixels,
    ) -> Vec<usize>;
}

#[derive(PartialEq, Eq, Hash, Clone)]
pub enum AtlasKey {
    Glyph(RenderGlyphParams),
    Svg(RenderSvgParams),
}

impl From<RenderGlyphParams> for AtlasKey {
    fn from(params: RenderGlyphParams) -> Self {
        Self::Glyph(params)
    }
}

impl From<RenderSvgParams> for AtlasKey {
    fn from(params: RenderSvgParams) -> Self {
        Self::Svg(params)
    }
}

pub trait PlatformAtlas: Send + Sync {
    fn get_or_insert_with(
        &self,
        key: &AtlasKey,
        build: &mut dyn FnMut() -> Result<(Size<DevicePixels>, Vec<u8>)>,
    ) -> Result<AtlasTile>;

    fn clear(&self);
}

#[derive(Clone, Debug, PartialEq, Eq)]
#[repr(C)]
pub struct AtlasTile {
    pub(crate) texture_id: AtlasTextureId,
    pub(crate) tile_id: TileId,
    pub(crate) bounds: Bounds<DevicePixels>,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
#[repr(C)]
pub(crate) struct AtlasTextureId(pub(crate) u32); // We use u32 instead of usize for Metal Shader Language compatibility

#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
#[repr(C)]
pub(crate) struct TileId(pub(crate) u32);

impl From<etagere::AllocId> for TileId {
    fn from(id: etagere::AllocId) -> Self {
        Self(id.serialize())
    }
}

impl From<TileId> for etagere::AllocId {
    fn from(id: TileId) -> Self {
        Self::deserialize(id.0)
    }
}

pub trait PlatformInputHandler {
    fn selected_text_range(&self) -> Option<Range<usize>>;
    fn marked_text_range(&self) -> Option<Range<usize>>;
    fn text_for_range(&self, range_utf16: Range<usize>) -> Option<String>;
    fn replace_text_in_range(&mut self, replacement_range: Option<Range<usize>>, text: &str);
    fn replace_and_mark_text_in_range(
        &mut self,
        range_utf16: Option<Range<usize>>,
        new_text: &str,
        new_selected_range: Option<Range<usize>>,
    );
    fn unmark_text(&mut self);
    fn bounds_for_range(&self, range_utf16: Range<usize>) -> Option<Bounds<f32>>;
}

#[derive(Copy, Clone, Debug, PartialEq)]
pub struct ScreenId(pub(crate) Uuid);

#[derive(Copy, Clone, Debug)]
pub enum RasterizationOptions {
    Alpha,
    Bgra,
}

#[derive(Debug)]
pub struct WindowOptions {
    pub bounds: WindowBounds,
    pub titlebar: Option<TitlebarOptions>,
    pub center: bool,
    pub focus: bool,
    pub show: bool,
    pub kind: WindowKind,
    pub is_movable: bool,
    pub screen: Option<PlatformScreenHandle>,
}

impl Default for WindowOptions {
    fn default() -> Self {
        Self {
            bounds: WindowBounds::default(),
            titlebar: Some(TitlebarOptions {
                title: Default::default(),
                appears_transparent: Default::default(),
                traffic_light_position: Default::default(),
            }),
            center: false,
            focus: true,
            show: true,
            kind: WindowKind::Normal,
            is_movable: true,
            screen: None,
        }
    }
}

#[derive(Debug, Default)]
pub struct TitlebarOptions {
    pub title: Option<SharedString>,
    pub appears_transparent: bool,
    pub traffic_light_position: Option<Point<Pixels>>,
}

#[derive(Copy, Clone, Debug)]
pub enum Appearance {
    Light,
    VibrantLight,
    Dark,
    VibrantDark,
}

impl Default for Appearance {
    fn default() -> Self {
        Self::Light
    }
}

#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum WindowKind {
    Normal,
    PopUp,
}

#[derive(Copy, Clone, Debug, PartialEq, Default)]
pub enum WindowBounds {
    Fullscreen,
    #[default]
    Maximized,
    Fixed(Bounds<Pixels>),
}

#[derive(Copy, Clone, Debug)]
pub enum WindowAppearance {
    Light,
    VibrantLight,
    Dark,
    VibrantDark,
}

impl Default for WindowAppearance {
    fn default() -> Self {
        Self::Light
    }
}

#[derive(Copy, Clone, Debug, PartialEq, Default)]
pub enum WindowPromptLevel {
    #[default]
    Info,
    Warning,
    Critical,
}

#[derive(Copy, Clone, Debug)]
pub struct PathPromptOptions {
    pub files: bool,
    pub directories: bool,
    pub multiple: bool,
}

#[derive(Copy, Clone, Debug)]
pub enum PromptLevel {
    Info,
    Warning,
    Critical,
}

#[derive(Copy, Clone, Debug)]
pub enum CursorStyle {
    Arrow,
    ResizeLeftRight,
    ResizeUpDown,
    PointingHand,
    IBeam,
}

impl Default for CursorStyle {
    fn default() -> Self {
        Self::Arrow
    }
}

#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
pub struct SemanticVersion {
    major: usize,
    minor: usize,
    patch: usize,
}

impl FromStr for SemanticVersion {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self> {
        let mut components = s.trim().split('.');
        let major = components
            .next()
            .ok_or_else(|| anyhow!("missing major version number"))?
            .parse()?;
        let minor = components
            .next()
            .ok_or_else(|| anyhow!("missing minor version number"))?
            .parse()?;
        let patch = components
            .next()
            .ok_or_else(|| anyhow!("missing patch version number"))?
            .parse()?;
        Ok(Self {
            major,
            minor,
            patch,
        })
    }
}

impl Display for SemanticVersion {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}.{}.{}", self.major, self.minor, self.patch)
    }
}

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct ClipboardItem {
    pub(crate) text: String,
    pub(crate) metadata: Option<String>,
}

impl ClipboardItem {
    pub fn new(text: String) -> Self {
        Self {
            text,
            metadata: None,
        }
    }

    pub fn with_metadata<T: Serialize>(mut self, metadata: T) -> Self {
        self.metadata = Some(serde_json::to_string(&metadata).unwrap());
        self
    }

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

    pub fn metadata<T>(&self) -> Option<T>
    where
        T: for<'a> Deserialize<'a>,
    {
        self.metadata
            .as_ref()
            .and_then(|m| serde_json::from_str(m).ok())
    }

    pub(crate) fn text_hash(text: &str) -> u64 {
        let mut hasher = SeaHasher::new();
        text.hash(&mut hasher);
        hasher.finish()
    }
}