// Take a look at the license at the top of the repository in the LICENSE file.

use std::mem;

use glib::{prelude::*, translate::*};
use gst::{
    format::{FormattedValue, SpecificFormattedValueFullRange},
    prelude::*,
};

use crate::{ffi, BaseParse, BaseParseFrame};

mod sealed {
    pub trait Sealed {}
    impl<T: super::IsA<super::BaseParse>> Sealed for T {}
}

pub trait BaseParseExtManual: sealed::Sealed + IsA<BaseParse> + 'static {
    #[doc(alias = "get_sink_pad")]
    fn sink_pad(&self) -> &gst::Pad {
        unsafe {
            let elt = &*(self.as_ptr() as *const ffi::GstBaseParse);
            &*(&elt.sinkpad as *const *mut gst::ffi::GstPad as *const gst::Pad)
        }
    }

    #[doc(alias = "get_src_pad")]
    fn src_pad(&self) -> &gst::Pad {
        unsafe {
            let elt = &*(self.as_ptr() as *const ffi::GstBaseParse);
            &*(&elt.srcpad as *const *mut gst::ffi::GstPad as *const gst::Pad)
        }
    }

    fn segment(&self) -> gst::Segment {
        unsafe {
            let ptr: &ffi::GstBaseParse = &*(self.as_ptr() as *const _);
            let sinkpad = self.sink_pad();
            let _guard = sinkpad.stream_lock();
            from_glib_none(&ptr.segment as *const gst::ffi::GstSegment)
        }
    }

    fn lost_sync(&self) -> bool {
        unsafe {
            let ptr: &ffi::GstBaseParse = &*(self.as_ptr() as *const _);
            let sinkpad = self.sink_pad();
            let _guard = sinkpad.stream_lock();
            ptr.flags & ffi::GST_BASE_PARSE_FLAG_LOST_SYNC as u32 != 0
        }
    }

    fn is_draining(&self) -> bool {
        unsafe {
            let ptr: &ffi::GstBaseParse = &*(self.as_ptr() as *const _);
            let sinkpad = self.sink_pad();
            let _guard = sinkpad.stream_lock();
            ptr.flags & ffi::GST_BASE_PARSE_FLAG_DRAINING as u32 != 0
        }
    }

    /// Sets the duration of the currently playing media. Subclass can use this
    /// when it is able to determine duration and/or notices a change in the media
    /// duration. Alternatively, if `interval` is non-zero (default), then stream
    /// duration is determined based on estimated bitrate, and updated every `interval`
    /// frames.
    /// ## `fmt`
    /// [`gst::Format`][crate::gst::Format].
    /// ## `duration`
    /// duration value.
    /// ## `interval`
    /// how often to update the duration estimate based on bitrate, or 0.
    #[doc(alias = "gst_base_parse_set_duration")]
    fn set_duration(&self, duration: impl FormattedValue, interval: u32) {
        unsafe {
            ffi::gst_base_parse_set_duration(
                self.as_ref().to_glib_none().0,
                duration.format().into_glib(),
                duration.into_raw_value(),
                interval as i32,
            );
        }
    }

    /// If frames per second is configured, parser can take care of buffer duration
    /// and timestamping. When performing segment clipping, or seeking to a specific
    /// location, a corresponding decoder might need an initial `lead_in` and a
    /// following `lead_out` number of frames to ensure the desired segment is
    /// entirely filled upon decoding.
    /// ## `fps_num`
    /// frames per second (numerator).
    /// ## `fps_den`
    /// frames per second (denominator).
    /// ## `lead_in`
    /// frames needed before a segment for subsequent decode
    /// ## `lead_out`
    /// frames needed after a segment
    #[doc(alias = "gst_base_parse_set_frame_rate")]
    fn set_frame_rate(&self, fps: gst::Fraction, lead_in: u32, lead_out: u32) {
        let (fps_num, fps_den) = fps.into();
        unsafe {
            ffi::gst_base_parse_set_frame_rate(
                self.as_ref().to_glib_none().0,
                fps_num as u32,
                fps_den as u32,
                lead_in,
                lead_out,
            );
        }
    }

    /// Default implementation of `GstBaseParseClass::convert`.
    /// ## `src_format`
    /// [`gst::Format`][crate::gst::Format] describing the source format.
    /// ## `src_value`
    /// Source value to be converted.
    /// ## `dest_format`
    /// [`gst::Format`][crate::gst::Format] defining the converted format.
    ///
    /// # Returns
    ///
    /// [`true`] if conversion was successful.
    ///
    /// ## `dest_value`
    /// Pointer where the conversion result will be put.
    #[doc(alias = "gst_base_parse_convert_default")]
    fn convert_default<U: SpecificFormattedValueFullRange>(
        &self,
        src_val: impl FormattedValue,
    ) -> Option<U> {
        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(ffi::gst_base_parse_convert_default(
                self.as_ref().to_glib_none().0,
                src_val.format().into_glib(),
                src_val.into_raw_value(),
                U::default_format().into_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(U::from_raw(U::default_format(), dest_val.assume_init()))
            } else {
                None
            }
        }
    }

    fn convert_default_generic(
        &self,
        src_val: impl FormattedValue,
        dest_format: gst::Format,
    ) -> Option<gst::GenericFormattedValue> {
        unsafe {
            let mut dest_val = mem::MaybeUninit::uninit();
            let ret = from_glib(ffi::gst_base_parse_convert_default(
                self.as_ref().to_glib_none().0,
                src_val.format().into_glib(),
                src_val.into_raw_value(),
                dest_format.into_glib(),
                dest_val.as_mut_ptr(),
            ));
            if ret {
                Some(gst::GenericFormattedValue::new(
                    dest_format,
                    dest_val.assume_init(),
                ))
            } else {
                None
            }
        }
    }

    /// Collects parsed data and pushes it downstream.
    /// Source pad caps must be set when this is called.
    ///
    /// If `frame`'s out_buffer is set, that will be used as subsequent frame data,
    /// and `size` amount will be flushed from the input data. The output_buffer size
    /// can differ from the consumed size indicated by `size`.
    ///
    /// Otherwise, `size` samples will be taken from the input and used for output,
    /// and the output's metadata (timestamps etc) will be taken as (optionally)
    /// set by the subclass on `frame`'s (input) buffer (which is otherwise
    /// ignored for any but the above purpose/information).
    ///
    /// Note that the latter buffer is invalidated by this call, whereas the
    /// caller retains ownership of `frame`.
    /// ## `frame`
    /// a [`BaseParseFrame`][crate::BaseParseFrame]
    /// ## `size`
    /// consumed input data represented by frame
    ///
    /// # Returns
    ///
    /// a [`gst::FlowReturn`][crate::gst::FlowReturn] that should be escalated to caller (of caller)
    #[doc(alias = "gst_base_parse_finish_frame")]
    fn finish_frame(
        &self,
        frame: BaseParseFrame,
        size: u32,
    ) -> Result<gst::FlowSuccess, gst::FlowError> {
        unsafe {
            try_from_glib(ffi::gst_base_parse_finish_frame(
                self.as_ref().to_glib_none().0,
                frame.to_glib_none().0,
                i32::try_from(size).expect("size higher than i32::MAX"),
            ))
        }
    }
}

impl<O: IsA<BaseParse>> BaseParseExtManual for O {}