use std::collections::vec_deque::IntoIter as VecDequeIter;

use CreationError;
use CursorState;
use Event;
use MouseCursor;
use Window;
use WindowBuilder;
use native_monitor::NativeMonitorId;

use libc;
use platform;

impl WindowBuilder {
    /// Initializes a new `WindowBuilder` with default values.
    #[inline]
    pub fn new() -> WindowBuilder {
        WindowBuilder {
            window: Default::default(),
            platform_specific: Default::default(),
        }
    }

    /// Requests the window to be of specific dimensions.
    ///
    /// Width and height are in pixels.
    #[inline]
    pub fn with_dimensions(mut self, width: u32, height: u32) -> WindowBuilder {
        self.window.dimensions = Some((width, height));
        self
    }
    
    /// Sets a minimum dimension size for the window
    ///
    /// Width and height are in pixels.
    #[inline]
    pub fn with_min_dimensions(mut self, width: u32, height: u32) -> WindowBuilder {
        self.window.min_dimensions = Some((width, height));
        self
    }

    /// Sets a maximum dimension size for the window
    ///
    /// Width and height are in pixels.
    #[inline]
    pub fn with_max_dimensions(mut self, width: u32, height: u32) -> WindowBuilder {
        self.window.max_dimensions = Some((width, height));
        self
    }

    /// Requests a specific title for the window.
    #[inline]
    pub fn with_title<T: Into<String>>(mut self, title: T) -> WindowBuilder {
        self.window.title = title.into();
        self
    }

    /// Requests fullscreen mode.
    ///
    /// If you don't specify dimensions for the window, it will match the monitor's.
    #[inline]
    pub fn with_fullscreen(mut self, monitor: MonitorId) -> WindowBuilder {
        let MonitorId(monitor) = monitor;
        self.window.monitor = Some(monitor);
        self
    }

    /// Sets whether the window will be initially hidden or visible.
    #[inline]
    pub fn with_visibility(mut self, visible: bool) -> WindowBuilder {
        self.window.visible = visible;
        self
    }

    /// Sets whether the background of the window should be transparent.
    #[inline]
    pub fn with_transparency(mut self, transparent: bool) -> WindowBuilder {
        self.window.transparent = transparent;
        self
    }

    /// Sets whether the window should have a border, a title bar, etc.
    #[inline]
    pub fn with_decorations(mut self, decorations: bool) -> WindowBuilder {
        self.window.decorations = decorations;
        self
    }

    /// Enables multitouch
    #[inline]
    pub fn with_multitouch(mut self) -> WindowBuilder {
        self.window.multitouch = true;
        self
    }

    /// Provides a resize callback that is called by Mac (and potentially other
    /// operating systems) during resize operations. This can be used to repaint
    /// during window resizing.
    #[inline]
    pub fn with_window_resize_callback(mut self, cb: fn(u32, u32)) -> WindowBuilder {
        self.window.resize_callback = Some(cb);
        self
    }

    /// Builds the window.
    ///
    /// Error should be very rare and only occur in case of permission denied, incompatible system,
    /// out of memory, etc.
    pub fn build(mut self) -> Result<Window, CreationError> {
        // resizing the window to the dimensions of the monitor when fullscreen
        if self.window.dimensions.is_none() && self.window.monitor.is_some() {
            self.window.dimensions = Some(self.window.monitor.as_ref().unwrap().get_dimensions())
        }

        // default dimensions
        if self.window.dimensions.is_none() {
            self.window.dimensions = Some((1024, 768));
        }

        // building
        let mut w = try!(platform::Window::new(&self.window, &self.platform_specific));

        // a window resize callback was given
        if let Some(callback) = self.window.resize_callback {
            w.set_window_resize_callback(Some(callback));
        }

        Ok(Window { window: w })
    }

    /// Builds the window.
    ///
    /// The context is build in a *strict* way. That means that if the backend couldn't give
    /// you what you requested, an `Err` will be returned.
    #[inline]
    pub fn build_strict(self) -> Result<Window, CreationError> {
        self.build()
    }
}


impl Default for Window {
    #[inline]
    fn default() -> Window {
        Window::new().unwrap()
    }
}

impl Window {
    /// Creates a new OpenGL context, and a Window for platforms where this is appropriate.
    ///
    /// This function is equivalent to `WindowBuilder::new().build()`.
    ///
    /// Error should be very rare and only occur in case of permission denied, incompatible system,
    ///  out of memory, etc.
    #[inline]
    pub fn new() -> Result<Window, CreationError> {
        let builder = WindowBuilder::new();
        builder.build()
    }

    /// Modifies the title of the window.
    ///
    /// This is a no-op if the window has already been closed.
    #[inline]
    pub fn set_title(&self, title: &str) {
        self.window.set_title(title)
    }

    /// Shows the window if it was hidden.
    ///
    /// ## Platform-specific
    ///
    /// - Has no effect on Android
    ///
    #[inline]
    pub fn show(&self) {
        self.window.show()
    }

    /// Hides the window if it was visible.
    ///
    /// ## Platform-specific
    ///
    /// - Has no effect on Android
    ///
    #[inline]
    pub fn hide(&self) {
        self.window.hide()
    }

    /// Returns the position of the top-left hand corner of the window relative to the
    ///  top-left hand corner of the desktop.
    ///
    /// Note that the top-left hand corner of the desktop is not necessarily the same as
    ///  the screen. If the user uses a desktop with multiple monitors, the top-left hand corner
    ///  of the desktop is the top-left hand corner of the monitor at the top-left of the desktop.
    ///
    /// The coordinates can be negative if the top-left hand corner of the window is outside
    ///  of the visible screen region.
    ///
    /// Returns `None` if the window no longer exists.
    #[inline]
    pub fn get_position(&self) -> Option<(i32, i32)> {
        self.window.get_position()
    }

    /// Modifies the position of the window.
    ///
    /// See `get_position` for more informations about the coordinates.
    ///
    /// This is a no-op if the window has already been closed.
    #[inline]
    pub fn set_position(&self, x: i32, y: i32) {
        self.window.set_position(x, y)
    }

    /// Returns the size in points of the client area of the window.
    ///
    /// The client area is the content of the window, excluding the title bar and borders.
    /// To get the dimensions of the frame buffer when calling `glViewport`, multiply with hidpi factor.
    ///
    /// Returns `None` if the window no longer exists.
    ///
    /// DEPRECATED
    #[inline]
    pub fn get_inner_size(&self) -> Option<(u32, u32)> {
        self.window.get_inner_size()
    }
    
    /// Returns the size in points of the client area of the window.
    ///
    /// The client area is the content of the window, excluding the title bar and borders.
    /// To get the dimensions of the frame buffer when calling `glViewport`, multiply with hidpi factor.
    ///
    /// Returns `None` if the window no longer exists.
    #[inline]
    pub fn get_inner_size_points(&self) -> Option<(u32, u32)> {
        self.window.get_inner_size()
    }


    /// Returns the size in pixels of the client area of the window.
    ///
    /// The client area is the content of the window, excluding the title bar and borders.
    /// These are the dimensions of the frame buffer, and the dimensions that you should use
    ///  when you call `glViewport`.
    ///
    /// Returns `None` if the window no longer exists.
    #[inline]
    pub fn get_inner_size_pixels(&self) -> Option<(u32, u32)> {
        self.window.get_inner_size().map(|(x, y)| {
            let hidpi = self.hidpi_factor();
            ((x as f32 * hidpi) as u32, (y as f32 * hidpi) as u32)
        })
    }

    /// Returns the size in pixels of the window.
    ///
    /// These dimensions include title bar and borders. If you don't want these, you should use
    ///  use `get_inner_size` instead.
    ///
    /// Returns `None` if the window no longer exists.
    #[inline]
    pub fn get_outer_size(&self) -> Option<(u32, u32)> {
        self.window.get_outer_size()
    }

    /// Modifies the inner size of the window.
    ///
    /// See `get_inner_size` for more informations about the values.
    ///
    /// This is a no-op if the window has already been closed.
    #[inline]
    pub fn set_inner_size(&self, x: u32, y: u32) {
        self.window.set_inner_size(x, y)
    }

    /// Returns an iterator that poll for the next event in the window's events queue.
    /// Returns `None` if there is no event in the queue.
    ///
    /// Contrary to `wait_events`, this function never blocks.
    #[inline]
    pub fn poll_events(&self) -> PollEventsIterator {
        PollEventsIterator(self.window.poll_events())
    }

    /// Returns an iterator that returns events one by one, blocking if necessary until one is
    /// available.
    ///
    /// The iterator never returns `None`.
    #[inline]
    pub fn wait_events(&self) -> WaitEventsIterator {
        WaitEventsIterator(self.window.wait_events())
    }

    /// DEPRECATED. Gets the native platform specific display for this window.
    /// This is typically only required when integrating with
    /// other libraries that need this information.
    #[deprecated]
    #[inline]
    pub unsafe fn platform_display(&self) -> *mut libc::c_void {
        self.window.platform_display()
    }

    /// DEPRECATED. Gets the native platform specific window handle. This is
    /// typically only required when integrating with other libraries
    /// that need this information.
    #[deprecated]
    #[inline]
    pub unsafe fn platform_window(&self) -> *mut libc::c_void {
        self.window.platform_window()
    }

    /// Create a window proxy for this window, that can be freely
    /// passed to different threads.
    #[inline]
    pub fn create_window_proxy(&self) -> WindowProxy {
        WindowProxy {
            proxy: self.window.create_window_proxy()
        }
    }

    /// Sets a resize callback that is called by Mac (and potentially other
    /// operating systems) during resize operations. This can be used to repaint
    /// during window resizing.
    #[inline]
    pub fn set_window_resize_callback(&mut self, callback: Option<fn(u32, u32)>) {
        self.window.set_window_resize_callback(callback);
    }

    /// Modifies the mouse cursor of the window.
    /// Has no effect on Android.
    pub fn set_cursor(&self, cursor: MouseCursor) {
        self.window.set_cursor(cursor);
    }

    /// Returns the ratio between the backing framebuffer resolution and the
    /// window size in screen pixels. This is typically one for a normal display
    /// and two for a retina display.
    #[inline]
    pub fn hidpi_factor(&self) -> f32 {
        self.window.hidpi_factor()
    }

    /// Changes the position of the cursor in window coordinates.
    #[inline]
    pub fn set_cursor_position(&self, x: i32, y: i32) -> Result<(), ()> {
        self.window.set_cursor_position(x, y)
    }

    /// Sets how glutin handles the cursor. See the documentation of `CursorState` for details.
    ///
    /// Has no effect on Android.
    #[inline]
    pub fn set_cursor_state(&self, state: CursorState) -> Result<(), String> {
        self.window.set_cursor_state(state)
    }
}

/// Represents a thread safe subset of operations that can be called
/// on a window. This structure can be safely cloned and sent between
/// threads.
#[derive(Clone)]
pub struct WindowProxy {
    proxy: platform::WindowProxy,
}

impl WindowProxy {
    /// Triggers a blocked event loop to wake up. This is
    /// typically called when another thread wants to wake
    /// up the blocked rendering thread to cause a refresh.
    #[inline]
    pub fn wakeup_event_loop(&self) {
        self.proxy.wakeup_event_loop();
    }
}

/// An iterator for the `poll_events` function.
pub struct PollEventsIterator<'a>(platform::PollEventsIterator<'a>);

impl<'a> Iterator for PollEventsIterator<'a> {
    type Item = Event;

    #[inline]
    fn next(&mut self) -> Option<Event> {
        self.0.next()
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.0.size_hint()
    }
}

/// An iterator for the `wait_events` function.
pub struct WaitEventsIterator<'a>(platform::WaitEventsIterator<'a>);

impl<'a> Iterator for WaitEventsIterator<'a> {
    type Item = Event;

    #[inline]
    fn next(&mut self) -> Option<Event> {
        self.0.next()
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.0.size_hint()
    }
}

/// An iterator for the list of available monitors.
// Implementation note: we retreive the list once, then serve each element by one by one.
// This may change in the future.
pub struct AvailableMonitorsIter {
    data: VecDequeIter<platform::MonitorId>,
}

impl Iterator for AvailableMonitorsIter {
    type Item = MonitorId;

    #[inline]
    fn next(&mut self) -> Option<MonitorId> {
        self.data.next().map(|id| MonitorId(id))
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.data.size_hint()
    }
}

/// Returns the list of all available monitors.
#[inline]
pub fn get_available_monitors() -> AvailableMonitorsIter {
    let data = platform::get_available_monitors();
    AvailableMonitorsIter{ data: data.into_iter() }
}

/// Returns the primary monitor of the system.
#[inline]
pub fn get_primary_monitor() -> MonitorId {
    MonitorId(platform::get_primary_monitor())
}

/// Identifier for a monitor.
pub struct MonitorId(platform::MonitorId);

impl MonitorId {
    /// Returns a human-readable name of the monitor.
    #[inline]
    pub fn get_name(&self) -> Option<String> {
        let &MonitorId(ref id) = self;
        id.get_name()
    }

    /// Returns the native platform identifier for this monitor.
    #[inline]
    pub fn get_native_identifier(&self) -> NativeMonitorId {
        let &MonitorId(ref id) = self;
        id.get_native_identifier()
    }

    /// Returns the number of pixels currently displayed on the monitor.
    #[inline]
    pub fn get_dimensions(&self) -> (u32, u32) {
        let &MonitorId(ref id) = self;
        id.get_dimensions()
    }
}