//! Boa's implementation of ECMAScript's global `DataView` object.
//!
//! More information:
//!  - [ECMAScript reference][spec]
//!  - [MDN documentation][mdn]
//!
//! [spec]: https://tc39.es/ecma262/#sec-dataview-objects
//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView

use std::{mem, sync::atomic::Ordering};

use crate::{
    builtins::BuiltInObject,
    context::intrinsics::{Intrinsics, StandardConstructor, StandardConstructors},
    error::JsNativeError,
    js_string,
    object::{internal_methods::get_prototype_from_constructor, JsObject},
    property::Attribute,
    realm::Realm,
    string::common::StaticJsStrings,
    symbol::JsSymbol,
    value::JsValue,
    Context, JsArgs, JsData, JsResult, JsString,
};
use boa_gc::{Finalize, Trace};
use bytemuck::{bytes_of, bytes_of_mut};

use super::{
    array_buffer::{
        utils::{memcpy, BytesConstPtr, BytesMutPtr},
        BufferObject,
    },
    typed_array::{self, TypedArrayElement},
    BuiltInBuilder, BuiltInConstructor, IntrinsicObject,
};

/// The internal representation of a `DataView` object.
#[derive(Debug, Clone, Trace, Finalize, JsData)]
pub struct DataView {
    pub(crate) viewed_array_buffer: BufferObject,
    pub(crate) byte_length: Option<u64>,
    pub(crate) byte_offset: u64,
}

impl DataView {
    /// Abstract operation [`GetViewByteLength ( viewRecord )`][spec].
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-getviewbytelength
    fn byte_length(&self, buf_byte_len: usize) -> u64 {
        // 1. Assert: IsViewOutOfBounds(viewRecord) is false.
        debug_assert!(!self.is_out_of_bounds(buf_byte_len));

        // 2. Let view be viewRecord.[[Object]].
        // 3. If view.[[ByteLength]] is not auto, return view.[[ByteLength]].
        if let Some(byte_length) = self.byte_length {
            return byte_length;
        }

        // 4. Assert: IsFixedLengthArrayBuffer(view.[[ViewedArrayBuffer]]) is false.

        // 5. Let byteOffset be view.[[ByteOffset]].
        // 6. Let byteLength be viewRecord.[[CachedBufferByteLength]].
        // 7. Assert: byteLength is not detached.
        // 8. Return byteLength - byteOffset.
        buf_byte_len as u64 - self.byte_offset
    }

    /// Abstract operation [`IsViewOutOfBounds ( viewRecord )`][spec].
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-isviewoutofbounds
    fn is_out_of_bounds(&self, buf_byte_len: usize) -> bool {
        let buf_byte_len = buf_byte_len as u64;
        // 1. Let view be viewRecord.[[Object]].
        // 2. Let bufferByteLength be viewRecord.[[CachedBufferByteLength]].
        // 3. Assert: IsDetachedBuffer(view.[[ViewedArrayBuffer]]) is true if and only if bufferByteLength is detached.
        // 4. If bufferByteLength is detached, return true.
        // handled by the caller

        // 5. Let byteOffsetStart be view.[[ByteOffset]].

        // 6. If view.[[ByteLength]] is auto, then
        //     a. Let byteOffsetEnd be bufferByteLength.
        // 7. Else,
        //     a. Let byteOffsetEnd be byteOffsetStart + view.[[ByteLength]].
        let byte_offset_end = self
            .byte_length
            .map_or(buf_byte_len, |byte_length| byte_length + self.byte_offset);

        // 8. If byteOffsetStart > bufferByteLength or byteOffsetEnd > bufferByteLength, return true.
        // 9. NOTE: 0-length DataViews are not considered out-of-bounds.
        // 10. Return false.
        self.byte_offset > buf_byte_len || byte_offset_end > buf_byte_len
    }
}

impl IntrinsicObject for DataView {
    fn init(realm: &Realm) {
        let flag_attributes = Attribute::CONFIGURABLE | Attribute::NON_ENUMERABLE;

        let get_buffer = BuiltInBuilder::callable(realm, Self::get_buffer)
            .name(js_string!("get buffer"))
            .build();

        let get_byte_length = BuiltInBuilder::callable(realm, Self::get_byte_length)
            .name(js_string!("get byteLength"))
            .build();

        let get_byte_offset = BuiltInBuilder::callable(realm, Self::get_byte_offset)
            .name(js_string!("get byteOffset"))
            .build();

        BuiltInBuilder::from_standard_constructor::<Self>(realm)
            .accessor(
                js_string!("buffer"),
                Some(get_buffer),
                None,
                flag_attributes,
            )
            .accessor(
                js_string!("byteLength"),
                Some(get_byte_length),
                None,
                flag_attributes,
            )
            .accessor(
                js_string!("byteOffset"),
                Some(get_byte_offset),
                None,
                flag_attributes,
            )
            .method(Self::get_big_int64, js_string!("getBigInt64"), 1)
            .method(Self::get_big_uint64, js_string!("getBigUint64"), 1)
            .method(Self::get_float32, js_string!("getFloat32"), 1)
            .method(Self::get_float64, js_string!("getFloat64"), 1)
            .method(Self::get_int8, js_string!("getInt8"), 1)
            .method(Self::get_int16, js_string!("getInt16"), 1)
            .method(Self::get_int32, js_string!("getInt32"), 1)
            .method(Self::get_uint8, js_string!("getUint8"), 1)
            .method(Self::get_uint16, js_string!("getUint16"), 1)
            .method(Self::get_uint32, js_string!("getUint32"), 1)
            .method(Self::set_big_int64, js_string!("setBigInt64"), 2)
            .method(Self::set_big_uint64, js_string!("setBigUint64"), 2)
            .method(Self::set_float32, js_string!("setFloat32"), 2)
            .method(Self::set_float64, js_string!("setFloat64"), 2)
            .method(Self::set_int8, js_string!("setInt8"), 2)
            .method(Self::set_int16, js_string!("setInt16"), 2)
            .method(Self::set_int32, js_string!("setInt32"), 2)
            .method(Self::set_uint8, js_string!("setUint8"), 2)
            .method(Self::set_uint16, js_string!("setUint16"), 2)
            .method(Self::set_uint32, js_string!("setUint32"), 2)
            .property(
                JsSymbol::to_string_tag(),
                Self::NAME,
                Attribute::READONLY | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
            )
            .build();
    }

    fn get(intrinsics: &Intrinsics) -> JsObject {
        Self::STANDARD_CONSTRUCTOR(intrinsics.constructors()).constructor()
    }
}

impl BuiltInObject for DataView {
    const NAME: JsString = StaticJsStrings::DATA_VIEW;
}

impl BuiltInConstructor for DataView {
    const LENGTH: usize = 1;

    const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
        StandardConstructors::data_view;

    /// `DataView ( buffer [ , byteOffset [ , byteLength ] ] )`
    ///
    /// The `DataView` view provides a low-level interface for reading and writing multiple number
    /// types in a binary `ArrayBuffer`, without having to care about the platform's endianness.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview-buffer-byteoffset-bytelength
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/DataView
    fn constructor(
        new_target: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. If NewTarget is undefined, throw a TypeError exception.
        if new_target.is_undefined() {
            return Err(JsNativeError::typ()
                .with_message("cannot call `DataView` constructor without `new`")
                .into());
        }
        let byte_len = args.get_or_undefined(2);

        // 2. Perform ? RequireInternalSlot(buffer, [[ArrayBufferData]]).
        let buffer = args
            .get_or_undefined(0)
            .as_object()
            .and_then(|o| o.clone().into_buffer_object().ok())
            .ok_or_else(|| JsNativeError::typ().with_message("buffer must be an ArrayBuffer"))?;

        // 3. Let offset be ? ToIndex(byteOffset).
        let offset = args.get_or_undefined(1).to_index(context)?;

        let (buf_byte_len, is_fixed_len) = {
            let buffer = buffer.as_buffer();

            // 4. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
            let Some(slice) = buffer.bytes(Ordering::SeqCst) else {
                return Err(JsNativeError::typ()
                    .with_message("ArrayBuffer is detached")
                    .into());
            };

            // 5. Let bufferByteLength be ArrayBufferByteLength(buffer, seq-cst).
            let buf_len = slice.len() as u64;

            // 6. If offset > bufferByteLength, throw a RangeError exception.
            if offset > buf_len {
                return Err(JsNativeError::range()
                    .with_message("Start offset is outside the bounds of the buffer")
                    .into());
            }

            // 7. Let bufferIsFixedLength be IsFixedLengthArrayBuffer(buffer).

            (buf_len, buffer.is_fixed_len())
        };

        // 8. If byteLength is undefined, then
        let view_byte_len = if byte_len.is_undefined() {
            // a. If bufferIsFixedLength is true, then
            //     i. Let viewByteLength be bufferByteLength - offset.
            // b. Else,
            //     i. Let viewByteLength be auto.
            is_fixed_len.then_some(buf_byte_len - offset)
        } else {
            // 9. Else,
            //     a. Let viewByteLength be ? ToIndex(byteLength).
            let byte_len = byte_len.to_index(context)?;

            //     b. If offset + viewByteLength > bufferByteLength, throw a RangeError exception.
            if offset + byte_len > buf_byte_len {
                return Err(JsNativeError::range()
                    .with_message("Invalid data view length")
                    .into());
            }
            Some(byte_len)
        };

        // 10. Let O be ? OrdinaryCreateFromConstructor(NewTarget, "%DataView.prototype%",
        //     « [[DataView]], [[ViewedArrayBuffer]], [[ByteLength]], [[ByteOffset]] »).
        let prototype =
            get_prototype_from_constructor(new_target, StandardConstructors::data_view, context)?;

        // 11. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
        // 12. Set bufferByteLength to ArrayBufferByteLength(buffer, seq-cst).
        let Some(buf_byte_len) = buffer
            .as_buffer()
            .bytes(Ordering::SeqCst)
            .map(|s| s.len() as u64)
        else {
            return Err(JsNativeError::typ()
                .with_message("ArrayBuffer can't be detached")
                .into());
        };

        // 13. If offset > bufferByteLength, throw a RangeError exception.
        if offset > buf_byte_len {
            return Err(JsNativeError::range()
                .with_message("DataView offset outside of buffer array bounds")
                .into());
        }

        // 14. If byteLength is not undefined, then
        if let Some(view_byte_len) = view_byte_len.filter(|_| !byte_len.is_undefined()) {
            // a. If offset + viewByteLength > bufferByteLength, throw a RangeError exception.
            if offset + view_byte_len > buf_byte_len {
                return Err(JsNativeError::range()
                    .with_message("DataView offset outside of buffer array bounds")
                    .into());
            }
        }

        let obj = JsObject::from_proto_and_data_with_shared_shape(
            context.root_shape(),
            prototype,
            Self {
                // 15. Set O.[[ViewedArrayBuffer]] to buffer.
                viewed_array_buffer: buffer,
                // 16. Set O.[[ByteLength]] to viewByteLength.
                byte_length: view_byte_len,
                // 17. Set O.[[ByteOffset]] to offset.
                byte_offset: offset,
            },
        );

        // 18. Return O.
        Ok(obj.into())
    }
}

impl DataView {
    /// `get DataView.prototype.buffer`
    ///
    /// The buffer accessor property represents the `ArrayBuffer` or `SharedArrayBuffer` referenced
    /// by the `DataView` at construction time.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-get-dataview.prototype.buffer
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/buffer
    pub(crate) fn get_buffer(
        this: &JsValue,
        _args: &[JsValue],
        _: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. Let O be the this value.
        // 2. Perform ? RequireInternalSlot(O, [[DataView]]).
        let view = this
            .as_object()
            .and_then(JsObject::downcast_ref::<Self>)
            .ok_or_else(|| JsNativeError::typ().with_message("`this` is not a DataView"))?;
        // 3. Assert: O has a [[ViewedArrayBuffer]] internal slot.
        // 4. Let buffer be O.[[ViewedArrayBuffer]].
        let buffer = view.viewed_array_buffer.clone();
        // 5. Return buffer.
        Ok(buffer.into())
    }

    /// `get DataView.prototype.byteLength`
    ///
    /// The `byteLength` accessor property represents the length (in bytes) of the dataview.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-get-dataview.prototype.bytelength
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/byteLength
    pub(crate) fn get_byte_length(
        this: &JsValue,
        _args: &[JsValue],
        _: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. Let O be the this value.
        // 2. Perform ? RequireInternalSlot(O, [[DataView]]).
        // 3. Assert: O has a [[ViewedArrayBuffer]] internal slot.
        let view = this
            .as_object()
            .and_then(JsObject::downcast_ref::<Self>)
            .ok_or_else(|| JsNativeError::typ().with_message("`this` is not a DataView"))?;

        // 4. Let viewRecord be MakeDataViewWithBufferWitnessRecord(O, seq-cst).
        // 5. If IsViewOutOfBounds(viewRecord) is true, throw a TypeError exception.
        let buffer = view.viewed_array_buffer.as_buffer();
        let Some(slice) = buffer
            .bytes(Ordering::SeqCst)
            .filter(|s| !view.is_out_of_bounds(s.len()))
        else {
            return Err(JsNativeError::typ()
                .with_message("view out of bounds for its inner buffer")
                .into());
        };

        // 6. Let size be GetViewByteLength(viewRecord).
        let size = view.byte_length(slice.len());

        // 7. Return 𝔽(size).
        Ok(size.into())
    }

    /// `get DataView.prototype.byteOffset`
    ///
    /// The `byteOffset` accessor property represents the offset (in bytes) of this view from the
    /// start of its `ArrayBuffer` or `SharedArrayBuffer`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-get-dataview.prototype.byteoffset
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/byteOffset
    pub(crate) fn get_byte_offset(
        this: &JsValue,
        _args: &[JsValue],
        _: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. Let O be the this value.
        // 2. Perform ? RequireInternalSlot(O, [[DataView]]).
        let view = this
            .as_object()
            .and_then(JsObject::downcast_ref::<Self>)
            .ok_or_else(|| JsNativeError::typ().with_message("`this` is not a DataView"))?;

        // 3. Assert: O has a [[ViewedArrayBuffer]] internal slot.
        let buffer = view.viewed_array_buffer.as_buffer();
        // 4. Let viewRecord be MakeDataViewWithBufferWitnessRecord(O, seq-cst).
        // 5. If IsViewOutOfBounds(viewRecord) is true, throw a TypeError exception.
        if buffer
            .bytes(Ordering::SeqCst)
            .filter(|b| !view.is_out_of_bounds(b.len()))
            .is_none()
        {
            return Err(JsNativeError::typ()
                .with_message("data view is outside the bounds of its inner buffer")
                .into());
        }

        // 6. Let offset be O.[[ByteOffset]].
        let offset = view.byte_offset;
        // 7. Return 𝔽(offset).
        Ok(offset.into())
    }

    /// `GetViewValue ( view, requestIndex, isLittleEndian, type )`
    ///
    /// The abstract operation `GetViewValue` takes arguments view, requestIndex, `isLittleEndian`,
    /// and type. It is used by functions on `DataView` instances to retrieve values from the
    /// view's buffer.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-getviewvalue
    fn get_view_value<T: typed_array::Element>(
        view: &JsValue,
        request_index: &JsValue,
        is_little_endian: &JsValue,
        context: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. Perform ? RequireInternalSlot(view, [[DataView]]).
        // 2. Assert: view has a [[ViewedArrayBuffer]] internal slot.
        let view = view
            .as_object()
            .and_then(JsObject::downcast_ref::<Self>)
            .ok_or_else(|| JsNativeError::typ().with_message("`this` is not a DataView"))?;

        // 3. Let getIndex be ? ToIndex(requestIndex).
        let get_index = request_index.to_index(context)?;

        // 4. Set isLittleEndian to ToBoolean(isLittleEndian).
        let is_little_endian = is_little_endian.to_boolean();

        // 6. Let viewRecord be MakeDataViewWithBufferWitnessRecord(view, unordered).
        // 7. NOTE: Bounds checking is not a synchronizing operation when view's backing buffer is a growable SharedArrayBuffer.
        // 8. If IsViewOutOfBounds(viewRecord) is true, throw a TypeError exception.
        let buffer = view.viewed_array_buffer.as_buffer();
        let Some(data) = buffer
            .bytes(Ordering::Relaxed)
            .filter(|buf| !view.is_out_of_bounds(buf.len()))
        else {
            return Err(JsNativeError::typ()
                .with_message("view out of bounds for its inner buffer")
                .into());
        };

        // 5. Let viewOffset be view.[[ByteOffset]].
        let view_offset = view.byte_offset;

        // 9. Let viewSize be GetViewByteLength(viewRecord).
        let view_size = view.byte_length(data.len());

        // 10. Let elementSize be the Element Size value specified in Table 71 for Element Type type.
        let element_size = mem::size_of::<T>() as u64;

        // 11. If getIndex + elementSize > viewSize, throw a RangeError exception.
        if get_index + element_size > view_size {
            return Err(JsNativeError::range()
                .with_message("Offset is outside the bounds of the DataView")
                .into());
        }

        // 12. Let bufferIndex be getIndex + viewOffset.
        let buffer_index = (get_index + view_offset) as usize;

        let src = data.subslice(buffer_index..);

        debug_assert!(src.len() >= mem::size_of::<T>());

        // 13. Return GetValueFromBuffer(view.[[ViewedArrayBuffer]], bufferIndex, type, false, unordered, isLittleEndian).
        // SAFETY: All previous checks ensure the element fits in the buffer.
        let value: TypedArrayElement = unsafe {
            let mut value = T::zeroed();
            memcpy(
                src.as_ptr(),
                BytesMutPtr::Bytes(bytes_of_mut(&mut value).as_mut_ptr()),
                mem::size_of::<T>(),
            );

            if is_little_endian {
                value.to_little_endian()
            } else {
                value.to_big_endian()
            }
            .into()
        };

        Ok(value.into())
    }

    /// `DataView.prototype.getBigInt64 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getBigInt64()` method gets a signed 64-bit integer (long long) at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getbigint64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getBigInt64
    pub(crate) fn get_big_int64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<i64>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getBigUint64 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getBigUint64()` method gets an unsigned 64-bit integer (unsigned long long) at the
    /// specified byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getbiguint64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getBigUint64
    pub(crate) fn get_big_uint64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<u64>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getBigUint64 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getFloat32()` method gets a signed 32-bit float (float) at the specified byte offset
    /// from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getfloat32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getFloat32
    pub(crate) fn get_float32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<f32>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getFloat64 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getFloat64()` method gets a signed 64-bit float (double) at the specified byte offset
    /// from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getfloat64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getFloat64
    pub(crate) fn get_float64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<f64>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getInt8 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getInt8()` method gets a signed 8-bit integer (byte) at the specified byte offset
    /// from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getint8
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getInt8
    pub(crate) fn get_int8(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<i8>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getInt16 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getInt16()` method gets a signed 16-bit integer (short) at the specified byte offset
    /// from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getint16
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getInt16
    pub(crate) fn get_int16(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<i16>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getInt32 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getInt32()` method gets a signed 32-bit integer (long) at the specified byte offset
    /// from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getint32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getInt32
    pub(crate) fn get_int32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<i32>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getUint8 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getUint8()` method gets an unsigned 8-bit integer (unsigned byte) at the specified
    /// byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getuint8
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getUint8
    pub(crate) fn get_uint8(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<u8>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getUint16 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getUint16()` method gets an unsigned 16-bit integer (unsigned short) at the specified
    /// byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getuint16
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getUint16
    pub(crate) fn get_uint16(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<u16>(this, byte_offset, is_little_endian, context)
    }

    /// `DataView.prototype.getUint32 ( byteOffset [ , littleEndian ] )`
    ///
    /// The `getUint32()` method gets an unsigned 32-bit integer (unsigned long) at the specified
    /// byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.getuint32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/getUint32
    pub(crate) fn get_uint32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let is_little_endian = args.get_or_undefined(1);
        // 1. Let v be the this value.
        // 2. Return ? GetViewValue(v, byteOffset, littleEndian, BigInt64).
        Self::get_view_value::<u32>(this, byte_offset, is_little_endian, context)
    }

    /// `SetViewValue ( view, requestIndex, isLittleEndian, type )`
    ///
    /// The abstract operation `SetViewValue` takes arguments view, requestIndex, `isLittleEndian`,
    /// type, and value. It is used by functions on `DataView` instances to store values into the
    /// view's buffer.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-setviewvalue
    fn set_view_value<T: typed_array::Element>(
        view: &JsValue,
        request_index: &JsValue,
        is_little_endian: &JsValue,
        value: &JsValue,
        context: &mut Context,
    ) -> JsResult<JsValue> {
        // 1. Perform ? RequireInternalSlot(view, [[DataView]]).
        // 2. Assert: view has a [[ViewedArrayBuffer]] internal slot.
        let view = view
            .as_object()
            .and_then(JsObject::downcast_ref::<Self>)
            .ok_or_else(|| JsNativeError::typ().with_message("`this` is not a DataView"))?;

        // 3. Let getIndex be ? ToIndex(requestIndex).
        let get_index = request_index.to_index(context)?;

        // 4. If IsBigIntElementType(type) is true, let numberValue be ? ToBigInt(value).
        // 5. Otherwise, let numberValue be ? ToNumber(value).
        let value = T::from_js_value(value, context)?;

        // 6. Set isLittleEndian to ToBoolean(isLittleEndian).
        let is_little_endian = is_little_endian.to_boolean();

        // 8. Let viewRecord be MakeDataViewWithBufferWitnessRecord(view, unordered).
        // 9. NOTE: Bounds checking is not a synchronizing operation when view's backing buffer is a growable SharedArrayBuffer.
        // 10. If IsViewOutOfBounds(viewRecord) is true, throw a TypeError exception.
        let mut buffer = view.viewed_array_buffer.as_buffer_mut();

        let Some(mut data) = buffer
            .bytes(Ordering::Relaxed)
            .filter(|buf| !view.is_out_of_bounds(buf.len()))
        else {
            return Err(JsNativeError::typ()
                .with_message("view out of bounds for its inner buffer")
                .into());
        };

        // 11. Let viewSize be GetViewByteLength(viewRecord).
        let view_size = view.byte_length(data.len());

        // 7. Let viewOffset be view.[[ByteOffset]].
        let view_offset = view.byte_offset;

        // 12. Let elementSize be the Element Size value specified in Table 71 for Element Type type.
        let elem_size = mem::size_of::<T>();

        // 13. If getIndex + elementSize > viewSize, throw a RangeError exception.
        if get_index + elem_size as u64 > view_size {
            return Err(JsNativeError::range()
                .with_message("Offset is outside the bounds of DataView")
                .into());
        }

        // 14. Let bufferIndex be getIndex + viewOffset.
        let buffer_index = (get_index + view_offset) as usize;

        let mut target = data.subslice_mut(buffer_index..);

        debug_assert!(target.len() >= mem::size_of::<T>());

        // 15. Perform SetValueInBuffer(view.[[ViewedArrayBuffer]], bufferIndex, type, numberValue, false, unordered, isLittleEndian).
        // SAFETY: All previous checks ensure the element fits in the buffer.
        unsafe {
            let value = if is_little_endian {
                value.to_little_endian()
            } else {
                value.to_big_endian()
            };

            memcpy(
                BytesConstPtr::Bytes(bytes_of(&value).as_ptr()),
                target.as_ptr(),
                mem::size_of::<T>(),
            );
        }

        // 16. Return undefined.
        Ok(JsValue::undefined())
    }

    /// `DataView.prototype.setBigInt64 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setBigInt64()` method stores a signed 64-bit integer (long long) value at the
    /// specified byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setbigint64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setBigInt64
    pub(crate) fn set_big_int64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, BigUint64, value).
        Self::set_view_value::<i64>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setBigUint64 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setBigUint64()` method stores an unsigned 64-bit integer (unsigned long long) value at
    /// the specified byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setbiguint64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setBigUint64
    pub(crate) fn set_big_uint64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, BigUint64, value).
        Self::set_view_value::<u64>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setFloat32 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setFloat32()` method stores a signed 32-bit float (float) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setfloat32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setFloat32
    pub(crate) fn set_float32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Float32, value).
        Self::set_view_value::<f32>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setFloat64 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setFloat64()` method stores a signed 64-bit float (double) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setfloat64
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setFloat64
    pub(crate) fn set_float64(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Float64, value).
        Self::set_view_value::<f64>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setInt8 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setInt8()` method stores a signed 8-bit integer (byte) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setint8
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setInt8
    pub(crate) fn set_int8(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Int8, value).
        Self::set_view_value::<i8>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setInt16 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setInt16()` method stores a signed 16-bit integer (short) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setint16
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setInt16
    pub(crate) fn set_int16(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Int16, value).
        Self::set_view_value::<i16>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setInt32 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setInt32()` method stores a signed 32-bit integer (long) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setint32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setInt32
    pub(crate) fn set_int32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Int32, value).
        Self::set_view_value::<i32>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setUint8 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setUint8()` method stores an unsigned 8-bit integer (byte) value at the specified byte
    /// offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setuint8
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setUint8
    pub(crate) fn set_uint8(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Uint8, value).
        Self::set_view_value::<u8>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setUint16 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setUint16()` method stores an unsigned 16-bit integer (unsigned short) value at the
    /// specified byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setuint16
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setUint16
    pub(crate) fn set_uint16(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Uint16, value).
        Self::set_view_value::<u16>(this, byte_offset, is_little_endian, value, context)
    }

    /// `DataView.prototype.setUint32 ( byteOffset, value [ , littleEndian ] )`
    ///
    /// The `setUint32()` method stores an unsigned 32-bit integer (unsigned long) value at the
    /// specified byte offset from the start of the `DataView`.
    ///
    /// More information:
    ///  - [ECMAScript reference][spec]
    ///  - [MDN][mdn]
    ///
    /// [spec]: https://tc39.es/ecma262/#sec-dataview.prototype.setuint32
    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView/setUint32
    pub(crate) fn set_uint32(
        this: &JsValue,
        args: &[JsValue],
        context: &mut Context,
    ) -> JsResult<JsValue> {
        let byte_offset = args.get_or_undefined(0);
        let value = args.get_or_undefined(1);
        let is_little_endian = args.get_or_undefined(2);
        // 1. Let v be the this value.
        // 2. Return ? SetViewValue(v, byteOffset, littleEndian, Uint32, value).
        Self::set_view_value::<u32>(this, byte_offset, is_little_endian, value, context)
    }
}