geoarrow-array 0.8.0

use std::sync::Arc;

use arrow_array::{Array, ArrayRef, FixedSizeListArray, StructArray};
use arrow_schema::DataType;
use geoarrow_schema::error::{GeoArrowError, GeoArrowResult};
use geoarrow_schema::{CoordType, Dimension};

use crate::array::{InterleavedCoordBuffer, SeparatedCoordBuffer};
use crate::builder::{InterleavedCoordBufferBuilder, SeparatedCoordBufferBuilder};
use crate::scalar::Coord;

/// An Arrow representation of an array of coordinates.
///
/// As defined in the GeoArrow spec, coordinates can either be interleaved (i.e. a single array of
/// XYXYXY) or separated (i.e. two arrays, one XXX and another YYY).
///
/// This CoordBuffer abstracts over an `InterleavedCoordBuffer` and a `SeparatedCoordBuffer`.
///
/// For now all coordinate buffers support only two dimensions.
///
/// This is named `CoordBuffer` instead of `CoordArray` because the buffer does not store its own
/// validity bitmask. Rather the geometry arrays that build on top of this maintain their own
/// validity masks.
#[derive(Debug, Clone)]
pub enum CoordBuffer {
    /// Interleaved coordinates
    Interleaved(InterleavedCoordBuffer),
    /// Separated coordinates
    Separated(SeparatedCoordBuffer),
}

impl CoordBuffer {
    /// Slice this buffer
    pub(crate) fn slice(&self, offset: usize, length: usize) -> Self {
        match self {
            CoordBuffer::Interleaved(c) => CoordBuffer::Interleaved(c.slice(offset, length)),
            CoordBuffer::Separated(c) => CoordBuffer::Separated(c.slice(offset, length)),
        }
    }

    /// The underlying coordinate type
    pub fn coord_type(&self) -> CoordType {
        match self {
            CoordBuffer::Interleaved(_) => CoordType::Interleaved,
            CoordBuffer::Separated(_) => CoordType::Separated,
        }
    }

    /// The arrow [DataType] for this coordinate buffer.
    pub(crate) fn storage_type(&self) -> DataType {
        match self {
            CoordBuffer::Interleaved(c) => c.storage_type(),
            CoordBuffer::Separated(c) => c.storage_type(),
        }
    }

    /// The length of this coordinate buffer
    pub fn len(&self) -> usize {
        match self {
            CoordBuffer::Interleaved(c) => c.len(),
            CoordBuffer::Separated(c) => c.len(),
        }
    }

    /// Whether this coordinate buffer is empty
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Returns the element at index `i`, not considering validity.
    ///
    /// # Examples
    ///
    /// ```
    /// use geo_traits::CoordTrait;
    /// use geoarrow_array::array::{CoordBuffer, SeparatedCoordBuffer};
    /// use geoarrow_schema::Dimension;
    ///
    /// let coords = [
    ///     geo_types::coord! { x: 1.0, y: 2.0 },
    ///     geo_types::coord! { x: 3.0, y: 4.0 },
    /// ];
    /// let coord_buffer = CoordBuffer::from(
    ///     SeparatedCoordBuffer::from_coords(coords.iter(), Dimension::XY).unwrap()
    /// );
    /// let coord = coord_buffer.value(0);
    /// assert_eq!(coord.x(), 1.0);
    /// assert_eq!(coord.y(), 2.0);
    /// ```
    ///
    /// # Panics
    ///
    /// Panics if the value is outside the bounds of the buffer.
    pub fn value(&self, index: usize) -> Coord<'_> {
        match self {
            CoordBuffer::Interleaved(c) => Coord::Interleaved(c.value(index)),
            CoordBuffer::Separated(c) => Coord::Separated(c.value(index)),
        }
    }

    /// Returns the element at index `i`, not considering validity.
    ///
    /// # Examples
    ///
    /// ```
    /// use geo_traits::CoordTrait;
    /// use geoarrow_array::array::{CoordBuffer, SeparatedCoordBuffer};
    /// use geoarrow_schema::Dimension;
    ///
    /// let coords = [
    ///     geo_types::coord! { x: 1.0, y: 2.0 },
    ///     geo_types::coord! { x: 3.0, y: 4.0 },
    /// ];
    /// let coord_buffer = CoordBuffer::from(
    ///     SeparatedCoordBuffer::from_coords(coords.iter(), Dimension::XY).unwrap()
    /// );
    /// let coord = unsafe { coord_buffer.value_unchecked(0) };
    /// assert_eq!(coord.x(), 1.0);
    /// assert_eq!(coord.y(), 2.0);
    /// ```
    ///
    /// # Safety
    ///
    /// Caller is responsible for ensuring that the index is within the bounds of the buffer.
    pub unsafe fn value_unchecked(&self, index: usize) -> Coord<'_> {
        match self {
            CoordBuffer::Interleaved(c) => Coord::Interleaved(unsafe { c.value_unchecked(index) }),
            CoordBuffer::Separated(c) => Coord::Separated(unsafe { c.value_unchecked(index) }),
        }
    }

    pub(crate) fn into_array_ref(self) -> ArrayRef {
        self.into()
    }

    /// The dimension of this coordinate buffer
    pub fn dim(&self) -> Dimension {
        match self {
            CoordBuffer::Interleaved(c) => c.dim(),
            CoordBuffer::Separated(c) => c.dim(),
        }
    }

    /// Convert this coordinate array into the given [CoordType]
    ///
    /// This is a no-op if the coord_type matches the existing coord type. Otherwise a full clone
    /// of the underlying coordinate buffers will be performed.
    pub fn into_coord_type(self, coord_type: CoordType) -> Self {
        let dim = self.dim();
        match (self, coord_type) {
            (CoordBuffer::Interleaved(cb), CoordType::Interleaved) => CoordBuffer::Interleaved(cb),
            (CoordBuffer::Interleaved(cb), CoordType::Separated) => {
                let mut new_buffer = SeparatedCoordBufferBuilder::with_capacity(cb.len(), dim);
                for i in 0..cb.len() {
                    let coord = cb.value(i);
                    new_buffer.push_coord(&coord);
                }
                CoordBuffer::Separated(new_buffer.finish())
            }
            (CoordBuffer::Separated(cb), CoordType::Separated) => CoordBuffer::Separated(cb),
            (CoordBuffer::Separated(cb), CoordType::Interleaved) => {
                let mut new_buffer = InterleavedCoordBufferBuilder::with_capacity(cb.len(), dim);
                for i in 0..cb.len() {
                    let coord = cb.value(i);
                    new_buffer.push_coord(&coord);
                }
                CoordBuffer::Interleaved(new_buffer.finish())
            }
        }
    }

    pub(crate) fn from_arrow(value: &dyn Array, dim: Dimension) -> GeoArrowResult<Self> {
        match value.data_type() {
            DataType::Struct(_) => {
                let downcasted = value.as_any().downcast_ref::<StructArray>().unwrap();
                Ok(CoordBuffer::Separated(SeparatedCoordBuffer::from_arrow(
                    downcasted, dim,
                )?))
            }
            DataType::FixedSizeList(_, _) => {
                let downcasted = value.as_any().downcast_ref::<FixedSizeListArray>().unwrap();
                Ok(CoordBuffer::Interleaved(
                    InterleavedCoordBuffer::from_arrow(downcasted, dim)?,
                ))
            }
            _ => Err(GeoArrowError::InvalidGeoArrow(format!(
                "Unexpected coord buffer type: {:?}",
                value.data_type()
            ))),
        }
    }
}

impl From<CoordBuffer> for ArrayRef {
    fn from(value: CoordBuffer) -> Self {
        match value {
            CoordBuffer::Interleaved(c) => Arc::new(FixedSizeListArray::from(c)),
            CoordBuffer::Separated(c) => Arc::new(StructArray::from(c)),
        }
    }
}

impl PartialEq for CoordBuffer {
    fn eq(&self, other: &Self) -> bool {
        match (self, other) {
            (CoordBuffer::Interleaved(a), CoordBuffer::Interleaved(b)) => PartialEq::eq(a, b),
            (CoordBuffer::Interleaved(left), CoordBuffer::Separated(right)) => {
                if left.len() != right.len() {
                    return false;
                }

                for i in 0..left.len() {
                    let left_coord = left.value(i);
                    let right_coord = right.value(i);

                    if left_coord != right_coord {
                        return false;
                    }
                }

                true
            }
            (CoordBuffer::Separated(a), CoordBuffer::Separated(b)) => PartialEq::eq(a, b),
            (CoordBuffer::Separated(left), CoordBuffer::Interleaved(right)) => {
                if left.len() != right.len() {
                    return false;
                }

                for i in 0..left.len() {
                    let left_coord = left.value(i);
                    let right_coord = right.value(i);

                    if left_coord != right_coord {
                        return false;
                    }
                }

                true
            }
        }
    }
}

impl From<InterleavedCoordBuffer> for CoordBuffer {
    fn from(value: InterleavedCoordBuffer) -> Self {
        Self::Interleaved(value)
    }
}

impl From<SeparatedCoordBuffer> for CoordBuffer {
    fn from(value: SeparatedCoordBuffer) -> Self {
        Self::Separated(value)
    }
}

// #[cfg(test)]
// mod test {
//     use crate::error::Result;

//     use super::*;

//     #[test]
//     fn test_eq_both_interleaved() -> Result<()> {
//         let coords1 = vec![0., 3., 1., 4., 2., 5.];
//         let buf1 =
//             CoordBuffer::Interleaved(InterleavedCoordBuffer::from_vec(coords1, Dimension::XY)?);

//         let coords2 = vec![0., 3., 1., 4., 2., 5.];
//         let buf2 =
//             CoordBuffer::Interleaved(InterleavedCoordBuffer::from_vec(coords2, Dimension::XY)?);

//         assert_eq!(buf1, buf2);
//         Ok(())
//     }

//     #[test]
//     fn test_eq_across_types() -> Result<()> {
//         let x1 = vec![0., 1., 2.];
//         let y1 = vec![3., 4., 5.];

//         let buf1 = CoordBuffer::Separated(SeparatedCoordBuffer::new(
//             [x1.into(), y1.into(), vec![].into(), vec![].into()],
//             Dimension::XY,
//         ));

//         let coords2 = vec![0., 3., 1., 4., 2., 5.];
//         let buf2 =
//             CoordBuffer::Interleaved(InterleavedCoordBuffer::new(coords2.into(), Dimension::XY));

//         assert_eq!(buf1, buf2);
//         Ok(())
//     }

//     #[test]
//     fn test_eq_across_types_slicing() -> Result<()> {
//         let x1 = vec![0., 1., 2.];
//         let y1 = vec![3., 4., 5.];

//         let buf1 = CoordBuffer::Separated((x1, y1).try_into()?).slice(1, 1);

//         let coords2 = vec![0., 3., 1., 4., 2., 5.];
//         let buf2 =
//             CoordBuffer::Interleaved(InterleavedCoordBuffer::new(coords2.into(), Dimension::XY))
//                 .slice(1, 1);

//         assert_eq!(buf1, buf2);
//         Ok(())
//     }
// }