// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.

use deno_core::error::AnyError;
use deno_core::op;
use deno_core::OpState;
use deno_core::Resource;
use deno_core::ResourceId;
use deno_core::ZeroCopyBuf;
use std::borrow::Cow;
use std::cell::RefCell;

use super::error::WebGpuResult;

pub(crate) struct WebGpuComputePass(pub(crate) RefCell<wgpu_core::command::ComputePass>);
impl Resource for WebGpuComputePass {
    fn name(&self) -> Cow<str> {
        "webGPUComputePass".into()
    }
}

#[op]
pub fn op_webgpu_compute_pass_set_pipeline(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    pipeline: ResourceId,
) -> Result<WebGpuResult, AnyError> {
    let compute_pipeline_resource = state
        .resource_table
        .get::<super::pipeline::WebGpuComputePipeline>(pipeline)?;
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_set_pipeline(
        &mut compute_pass_resource.0.borrow_mut(),
        compute_pipeline_resource.1,
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_dispatch_workgroups(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    x: u32,
    y: u32,
    z: u32,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_dispatch_workgroups(
        &mut compute_pass_resource.0.borrow_mut(),
        x,
        y,
        z,
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_dispatch_workgroups_indirect(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    indirect_buffer: ResourceId,
    indirect_offset: u64,
) -> Result<WebGpuResult, AnyError> {
    let buffer_resource = state
        .resource_table
        .get::<super::buffer::WebGpuBuffer>(indirect_buffer)?;
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_dispatch_workgroups_indirect(
        &mut compute_pass_resource.0.borrow_mut(),
        buffer_resource.1,
        indirect_offset,
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_begin_pipeline_statistics_query(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    query_set: ResourceId,
    query_index: u32,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;
    let query_set_resource = state
        .resource_table
        .get::<super::WebGpuQuerySet>(query_set)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_begin_pipeline_statistics_query(
        &mut compute_pass_resource.0.borrow_mut(),
        query_set_resource.1,
        query_index,
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_end_pipeline_statistics_query(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_end_pipeline_statistics_query(
        &mut compute_pass_resource.0.borrow_mut(),
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_write_timestamp(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    query_set: ResourceId,
    query_index: u32,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;
    let query_set_resource = state
        .resource_table
        .get::<super::WebGpuQuerySet>(query_set)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_write_timestamp(
        &mut compute_pass_resource.0.borrow_mut(),
        query_set_resource.1,
        query_index,
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_end(
    state: &mut OpState,
    command_encoder_rid: ResourceId,
    compute_pass_rid: ResourceId,
) -> Result<WebGpuResult, AnyError> {
    let command_encoder_resource =
        state
            .resource_table
            .get::<super::command_encoder::WebGpuCommandEncoder>(command_encoder_rid)?;
    let command_encoder = command_encoder_resource.1;
    let compute_pass_resource = state
        .resource_table
        .take::<WebGpuComputePass>(compute_pass_rid)?;
    let compute_pass = &compute_pass_resource.0.borrow();
    let instance = state.borrow::<super::Instance>();

    gfx_ok!(command_encoder => instance.command_encoder_run_compute_pass(
      command_encoder,
      compute_pass
    ))
}

#[op]
pub fn op_webgpu_compute_pass_set_bind_group(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    index: u32,
    bind_group: ResourceId,
    dynamic_offsets_data: ZeroCopyBuf,
    dynamic_offsets_data_start: usize,
    dynamic_offsets_data_length: usize,
) -> Result<WebGpuResult, AnyError> {
    let bind_group_resource = state
        .resource_table
        .get::<super::binding::WebGpuBindGroup>(bind_group)?;
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    // Align the data
    assert!(dynamic_offsets_data_start % std::mem::size_of::<u32>() == 0);
    // SAFETY: A u8 to u32 cast is safe because we asserted that the length is a
    // multiple of 4.
    let (prefix, dynamic_offsets_data, suffix) = unsafe { dynamic_offsets_data.align_to::<u32>() };
    assert!(prefix.is_empty());
    assert!(suffix.is_empty());

    let start = dynamic_offsets_data_start;
    let len = dynamic_offsets_data_length;

    // Assert that length and start are both in bounds
    assert!(start <= dynamic_offsets_data.len());
    assert!(len <= dynamic_offsets_data.len() - start);

    let dynamic_offsets_data: &[u32] = &dynamic_offsets_data[start..start + len];

    // SAFETY: the raw pointer and length are of the same slice, and that slice
    // lives longer than the below function invocation.
    unsafe {
        wgpu_core::command::compute_ffi::wgpu_compute_pass_set_bind_group(
            &mut compute_pass_resource.0.borrow_mut(),
            index,
            bind_group_resource.1,
            dynamic_offsets_data.as_ptr(),
            dynamic_offsets_data.len(),
        );
    }

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_push_debug_group(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    group_label: String,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    let label = std::ffi::CString::new(group_label).unwrap();
    // SAFETY: the string the raw pointer points to lives longer than the below
    // function invocation.
    unsafe {
        wgpu_core::command::compute_ffi::wgpu_compute_pass_push_debug_group(
            &mut compute_pass_resource.0.borrow_mut(),
            label.as_ptr(),
            0, // wgpu#975
        );
    }

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_pop_debug_group(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    wgpu_core::command::compute_ffi::wgpu_compute_pass_pop_debug_group(
        &mut compute_pass_resource.0.borrow_mut(),
    );

    Ok(WebGpuResult::empty())
}

#[op]
pub fn op_webgpu_compute_pass_insert_debug_marker(
    state: &mut OpState,
    compute_pass_rid: ResourceId,
    marker_label: String,
) -> Result<WebGpuResult, AnyError> {
    let compute_pass_resource = state
        .resource_table
        .get::<WebGpuComputePass>(compute_pass_rid)?;

    let label = std::ffi::CString::new(marker_label).unwrap();
    // SAFETY: the string the raw pointer points to lives longer than the below
    // function invocation.
    unsafe {
        wgpu_core::command::compute_ffi::wgpu_compute_pass_insert_debug_marker(
            &mut compute_pass_resource.0.borrow_mut(),
            label.as_ptr(),
            0, // wgpu#975
        );
    }

    Ok(WebGpuResult::empty())
}
