use crate::api::event::create_and_queue;
use crate::api::icd::*;
use crate::api::util::*;
use crate::core::event::*;
use crate::core::kernel::*;

use mesa_rust_util::ptr::*;
use mesa_rust_util::string::*;
use rusticl_opencl_gen::*;

use std::mem;
use std::os::raw::c_void;
use std::ptr;
use std::slice;
use std::sync::Arc;

impl CLInfo<cl_kernel_info> for cl_kernel {
    fn query(&self, q: cl_kernel_info, _: &[u8]) -> CLResult<Vec<u8>> {
        let kernel = self.get_ref()?;
        Ok(match q {
            CL_KERNEL_ATTRIBUTES => cl_prop::<&str>(&kernel.attributes_string),
            CL_KERNEL_CONTEXT => {
                let ptr = Arc::as_ptr(&kernel.prog.context);
                cl_prop::<cl_context>(cl_context::from_ptr(ptr))
            }
            CL_KERNEL_FUNCTION_NAME => cl_prop::<&str>(&kernel.name),
            CL_KERNEL_NUM_ARGS => cl_prop::<cl_uint>(kernel.args.len() as cl_uint),
            CL_KERNEL_PROGRAM => {
                let ptr = Arc::as_ptr(&kernel.prog);
                cl_prop::<cl_program>(cl_program::from_ptr(ptr))
            }
            CL_KERNEL_REFERENCE_COUNT => cl_prop::<cl_uint>(self.refcnt()?),
            // CL_INVALID_VALUE if param_name is not one of the supported values
            _ => return Err(CL_INVALID_VALUE),
        })
    }
}

impl CLInfoObj<cl_kernel_arg_info, cl_uint> for cl_kernel {
    fn query(&self, idx: cl_uint, q: cl_kernel_arg_info) -> CLResult<Vec<u8>> {
        let kernel = self.get_ref()?;

        // CL_INVALID_ARG_INDEX if arg_index is not a valid argument index.
        if idx as usize >= kernel.args.len() {
            return Err(CL_INVALID_ARG_INDEX);
        }

        Ok(match *q {
            CL_KERNEL_ARG_ACCESS_QUALIFIER => {
                cl_prop::<cl_kernel_arg_access_qualifier>(kernel.access_qualifier(idx))
            }
            CL_KERNEL_ARG_ADDRESS_QUALIFIER => {
                cl_prop::<cl_kernel_arg_address_qualifier>(kernel.address_qualifier(idx))
            }
            CL_KERNEL_ARG_NAME => cl_prop::<&str>(kernel.arg_name(idx)),
            CL_KERNEL_ARG_TYPE_NAME => cl_prop::<&str>(kernel.arg_type_name(idx)),
            CL_KERNEL_ARG_TYPE_QUALIFIER => {
                cl_prop::<cl_kernel_arg_type_qualifier>(kernel.type_qualifier(idx))
            }
            // CL_INVALID_VALUE if param_name is not one of the supported values
            _ => return Err(CL_INVALID_VALUE),
        })
    }
}

impl CLInfoObj<cl_kernel_work_group_info, cl_device_id> for cl_kernel {
    fn query(&self, dev: cl_device_id, q: cl_kernel_work_group_info) -> CLResult<Vec<u8>> {
        let kernel = self.get_ref()?;

        // CL_INVALID_DEVICE [..] if device is NULL but there is more than one device associated with kernel.
        let dev = if dev.is_null() {
            if kernel.prog.devs.len() > 1 {
                return Err(CL_INVALID_DEVICE);
            } else {
                kernel.prog.devs[0].clone()
            }
        } else {
            dev.get_arc()?
        };

        // CL_INVALID_DEVICE if device is not in the list of devices associated with kernel
        if !kernel.prog.devs.contains(&dev) {
            return Err(CL_INVALID_DEVICE);
        }

        Ok(match *q {
            CL_KERNEL_COMPILE_WORK_GROUP_SIZE => cl_prop::<[usize; 3]>(kernel.work_group_size),
            CL_KERNEL_LOCAL_MEM_SIZE => cl_prop::<cl_ulong>(kernel.local_mem_size(&dev)),
            CL_KERNEL_PREFERRED_WORK_GROUP_SIZE_MULTIPLE => {
                cl_prop::<usize>(kernel.preferred_simd_size(&dev))
            }
            CL_KERNEL_PRIVATE_MEM_SIZE => cl_prop::<cl_ulong>(kernel.priv_mem_size(&dev)),
            CL_KERNEL_WORK_GROUP_SIZE => cl_prop::<usize>(kernel.max_threads_per_block(&dev)),
            // CL_INVALID_VALUE if param_name is not one of the supported values
            _ => return Err(CL_INVALID_VALUE),
        })
    }
}

impl CLInfoObj<cl_kernel_sub_group_info, (cl_device_id, usize, *const c_void)> for cl_kernel {
    fn query(
        &self,
        (d, _input_value_size, _input_value): (cl_device_id, usize, *const c_void),
        _q: cl_program_build_info,
    ) -> CLResult<Vec<u8>> {
        let _kernel = self.get_ref()?;
        let _dev = d.get_arc()?;

        Err(CL_INVALID_OPERATION)
    }
}

const ZERO_ARR: [usize; 3] = [0; 3];

/// # Safety
///
/// This function is only safe when called on an array of `work_dim` length
unsafe fn kernel_work_arr_or_default<'a>(arr: *const usize, work_dim: cl_uint) -> &'a [usize] {
    if !arr.is_null() {
        slice::from_raw_parts(arr, work_dim as usize)
    } else {
        &ZERO_ARR
    }
}

pub fn create_kernel(
    program: cl_program,
    kernel_name: *const ::std::os::raw::c_char,
) -> CLResult<cl_kernel> {
    let p = program.get_arc()?;
    let name = c_string_to_string(kernel_name);

    // CL_INVALID_VALUE if kernel_name is NULL.
    if kernel_name.is_null() {
        return Err(CL_INVALID_VALUE);
    }

    // CL_INVALID_PROGRAM_EXECUTABLE if there is no successfully built executable for program.
    if p.kernels().is_empty() {
        return Err(CL_INVALID_PROGRAM_EXECUTABLE);
    }

    // CL_INVALID_KERNEL_NAME if kernel_name is not found in program.
    if !p.kernels().contains(&name) {
        return Err(CL_INVALID_KERNEL_NAME);
    }

    // CL_INVALID_KERNEL_DEFINITION if the function definition for __kernel function given by
    // kernel_name such as the number of arguments, the argument types are not the same for all
    // devices for which the program executable has been built.
    if p.kernel_signatures(&name).len() != 1 {
        return Err(CL_INVALID_KERNEL_DEFINITION);
    }

    Ok(cl_kernel::from_arc(Kernel::new(name, p)))
}

pub fn create_kernels_in_program(
    program: cl_program,
    num_kernels: cl_uint,
    kernels: *mut cl_kernel,
    num_kernels_ret: *mut cl_uint,
) -> CLResult<()> {
    let p = program.get_arc()?;

    // CL_INVALID_PROGRAM_EXECUTABLE if there is no successfully built executable for any device in
    // program.
    if p.kernels().is_empty() {
        return Err(CL_INVALID_PROGRAM_EXECUTABLE);
    }

    // CL_INVALID_VALUE if kernels is not NULL and num_kernels is less than the number of kernels
    // in program.
    if !kernels.is_null() && p.kernels().len() > num_kernels as usize {
        return Err(CL_INVALID_VALUE);
    }

    let mut num_kernels = 0;
    for name in p.kernels() {
        // Kernel objects are not created for any __kernel functions in program that do not have the
        // same function definition across all devices for which a program executable has been
        // successfully built.
        if p.kernel_signatures(&name).len() != 1 {
            continue;
        }

        if !kernels.is_null() {
            // we just assume the client isn't stupid
            unsafe {
                kernels
                    .add(num_kernels as usize)
                    .write(cl_kernel::from_arc(Kernel::new(name, p.clone())));
            }
        }
        num_kernels += 1;
    }
    num_kernels_ret.write_checked(num_kernels);
    Ok(())
}

pub fn set_kernel_arg(
    kernel: cl_kernel,
    arg_index: cl_uint,
    arg_size: usize,
    arg_value: *const ::std::os::raw::c_void,
) -> CLResult<()> {
    let k = kernel.get_arc()?;

    // CL_INVALID_ARG_INDEX if arg_index is not a valid argument index.
    if let Some(arg) = k.args.get(arg_index as usize) {
        // CL_INVALID_ARG_SIZE if arg_size does not match the size of the data type for an argument
        // that is not a memory object or if the argument is a memory object and
        // arg_size != sizeof(cl_mem) or if arg_size is zero and the argument is declared with the
        // local qualifier or if the argument is a sampler and arg_size != sizeof(cl_sampler).
        match arg.kind {
            KernelArgType::MemLocal => {
                if arg_size == 0 {
                    return Err(CL_INVALID_ARG_SIZE);
                }
            }
            KernelArgType::MemGlobal
            | KernelArgType::MemConstant
            | KernelArgType::Image
            | KernelArgType::RWImage
            | KernelArgType::Texture => {
                if arg_size != std::mem::size_of::<cl_mem>() {
                    return Err(CL_INVALID_ARG_SIZE);
                }
            }
            _ => {
                if arg.size != arg_size {
                    return Err(CL_INVALID_ARG_SIZE);
                }
            }
        }

        // CL_INVALID_ARG_VALUE if arg_value specified is not a valid value.
        match arg.kind {
            // If the argument is declared with the local qualifier, the arg_value entry must be
            // NULL.
            KernelArgType::MemLocal => {
                if !arg_value.is_null() {
                    return Err(CL_INVALID_ARG_VALUE);
                }
            }
            // If the argument is of type sampler_t, the arg_value entry must be a pointer to the
            // sampler object.
            KernelArgType::Constant | KernelArgType::Sampler => {
                if arg_value.is_null() {
                    return Err(CL_INVALID_ARG_VALUE);
                }
            }
            _ => {}
        };

        // let's create the arg now
        let arg = unsafe {
            if arg.dead {
                KernelArgValue::None
            } else {
                match arg.kind {
                    KernelArgType::Constant => KernelArgValue::Constant(
                        slice::from_raw_parts(arg_value.cast(), arg_size).to_vec(),
                    ),
                    KernelArgType::MemConstant | KernelArgType::MemGlobal => {
                        let ptr: *const cl_mem = arg_value.cast();
                        if ptr.is_null() || (*ptr).is_null() {
                            KernelArgValue::None
                        } else {
                            KernelArgValue::MemObject((*ptr).get_arc()?)
                        }
                    }
                    KernelArgType::MemLocal => KernelArgValue::LocalMem(arg_size),
                    KernelArgType::Image | KernelArgType::RWImage | KernelArgType::Texture => {
                        let img: *const cl_mem = arg_value.cast();
                        KernelArgValue::MemObject((*img).get_arc()?)
                    }
                    KernelArgType::Sampler => {
                        let ptr: *const cl_sampler = arg_value.cast();
                        KernelArgValue::Sampler((*ptr).get_arc()?)
                    }
                }
            }
        };
        k.values.get(arg_index as usize).unwrap().replace(Some(arg));
        Ok(())
    } else {
        Err(CL_INVALID_ARG_INDEX)
    }

    //• CL_INVALID_DEVICE_QUEUE for an argument declared to be of type queue_t when the specified arg_value is not a valid device queue object. This error code is missing before version 2.0.
    //• CL_INVALID_ARG_VALUE if the argument is an image declared with the read_only qualifier and arg_value refers to an image object created with cl_mem_flags of CL_MEM_WRITE_ONLY or if the image argument is declared with the write_only qualifier and arg_value refers to an image object created with cl_mem_flags of CL_MEM_READ_ONLY.
    //• CL_MAX_SIZE_RESTRICTION_EXCEEDED if the size in bytes of the memory object (if the argument is a memory object) or arg_size (if the argument is declared with local qualifier) exceeds a language- specified maximum size restriction for this argument, such as the MaxByteOffset SPIR-V decoration. This error code is missing before version 2.2.
}

pub fn set_kernel_arg_svm_pointer(
    kernel: cl_kernel,
    arg_index: cl_uint,
    arg_value: *const ::std::os::raw::c_void,
) -> CLResult<()> {
    let kernel = kernel.get_ref()?;
    let arg_index = arg_index as usize;
    let arg_value = arg_value as usize;

    if !kernel.has_svm_devs() {
        return Err(CL_INVALID_OPERATION);
    }

    if let Some(arg) = kernel.args.get(arg_index) {
        if !matches!(
            arg.kind,
            KernelArgType::MemConstant | KernelArgType::MemGlobal
        ) {
            return Err(CL_INVALID_ARG_INDEX);
        }

        let arg_value = KernelArgValue::Constant(arg_value.to_ne_bytes().to_vec());
        kernel.values[arg_index].replace(Some(arg_value));
        Ok(())
    } else {
        Err(CL_INVALID_ARG_INDEX)
    }

    // CL_INVALID_ARG_VALUE if arg_value specified is not a valid value.
}

pub fn set_kernel_exec_info(
    kernel: cl_kernel,
    param_name: cl_kernel_exec_info,
    param_value_size: usize,
    param_value: *const ::std::os::raw::c_void,
) -> CLResult<()> {
    let k = kernel.get_ref()?;

    // CL_INVALID_OPERATION if no devices in the context associated with kernel support SVM.
    if !k.prog.devs.iter().any(|dev| dev.svm_supported()) {
        return Err(CL_INVALID_OPERATION);
    }

    // CL_INVALID_VALUE ... if param_value is NULL
    if param_value.is_null() {
        return Err(CL_INVALID_VALUE);
    }

    // CL_INVALID_VALUE ... if the size specified by param_value_size is not valid.
    match param_name {
        CL_KERNEL_EXEC_INFO_SVM_PTRS | CL_KERNEL_EXEC_INFO_SVM_PTRS_ARM => {
            // it's a list of pointers
            if param_value_size % mem::size_of::<*const c_void>() != 0 {
                return Err(CL_INVALID_VALUE);
            }
        }
        CL_KERNEL_EXEC_INFO_SVM_FINE_GRAIN_SYSTEM
        | CL_KERNEL_EXEC_INFO_SVM_FINE_GRAIN_SYSTEM_ARM => {
            if param_value_size != mem::size_of::<cl_bool>() {
                return Err(CL_INVALID_VALUE);
            }
        }
        // CL_INVALID_VALUE if param_name is not valid
        _ => return Err(CL_INVALID_VALUE),
    }

    Ok(())

    // CL_INVALID_OPERATION if param_name is CL_KERNEL_EXEC_INFO_SVM_FINE_GRAIN_SYSTEM and param_value is CL_TRUE but no devices in context associated with kernel support fine-grain system SVM allocations.
}

pub fn enqueue_ndrange_kernel(
    command_queue: cl_command_queue,
    kernel: cl_kernel,
    work_dim: cl_uint,
    global_work_offset: *const usize,
    global_work_size: *const usize,
    local_work_size: *const usize,
    num_events_in_wait_list: cl_uint,
    event_wait_list: *const cl_event,
    event: *mut cl_event,
) -> CLResult<()> {
    let q = command_queue.get_arc()?;
    let k = kernel.get_arc()?;
    let evs = event_list_from_cl(&q, num_events_in_wait_list, event_wait_list)?;

    // CL_INVALID_CONTEXT if context associated with command_queue and kernel are not the same
    if q.context != k.prog.context {
        return Err(CL_INVALID_CONTEXT);
    }

    // CL_INVALID_PROGRAM_EXECUTABLE if there is no successfully built program executable available
    // for device associated with command_queue.
    if k.prog.status(&q.device) != CL_BUILD_SUCCESS as cl_build_status {
        return Err(CL_INVALID_PROGRAM_EXECUTABLE);
    }

    // CL_INVALID_KERNEL_ARGS if the kernel argument values have not been specified.
    if k.values.iter().any(|v| v.borrow().is_none()) {
        return Err(CL_INVALID_KERNEL_ARGS);
    }

    // CL_INVALID_WORK_DIMENSION if work_dim is not a valid value (i.e. a value between 1 and
    // CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS).
    if work_dim == 0 || work_dim > q.device.max_grid_dimensions() {
        return Err(CL_INVALID_WORK_DIMENSION);
    }

    // we assume the application gets it right and doesn't pass shorter arrays then actually needed.
    let global_work_size = unsafe { kernel_work_arr_or_default(global_work_size, work_dim) };
    let local_work_size = unsafe { kernel_work_arr_or_default(local_work_size, work_dim) };
    let global_work_offset = unsafe { kernel_work_arr_or_default(global_work_offset, work_dim) };

    let device_bits = q.device.address_bits();
    let device_max = u64::MAX >> (u64::BITS - device_bits);

    for i in 0..work_dim as usize {
        let lws = local_work_size[i];
        let gws = global_work_size[i];
        let gwo = global_work_offset[i];

        // CL_INVALID_WORK_ITEM_SIZE if the number of work-items specified in any of
        // local_work_size[0], … local_work_size[work_dim - 1] is greater than the corresponding
        // values specified by
        // CL_DEVICE_MAX_WORK_ITEM_SIZES[0], …, CL_DEVICE_MAX_WORK_ITEM_SIZES[work_dim - 1].
        if lws > q.device.max_block_sizes()[i] {
            return Err(CL_INVALID_WORK_ITEM_SIZE);
        }

        // CL_INVALID_WORK_GROUP_SIZE if the work-group size must be uniform and the
        // local_work_size is not NULL, [...] if the global_work_size is not evenly divisible by
        // the local_work_size.
        if lws != 0 && gws % lws != 0 {
            return Err(CL_INVALID_WORK_GROUP_SIZE);
        }

        // CL_INVALID_WORK_GROUP_SIZE if local_work_size is specified and does not match the
        // required work-group size for kernel in the program source.
        if lws != 0 && k.work_group_size[i] != 0 && lws != k.work_group_size[i] {
            return Err(CL_INVALID_WORK_GROUP_SIZE);
        }

        // CL_INVALID_GLOBAL_WORK_SIZE if any of the values specified in global_work_size[0], …
        // global_work_size[work_dim - 1] exceed the maximum value representable by size_t on
        // the device on which the kernel-instance will be enqueued.
        if gws as u64 > device_max {
            return Err(CL_INVALID_GLOBAL_WORK_SIZE);
        }

        // CL_INVALID_GLOBAL_OFFSET if the value specified in global_work_size + the
        // corresponding values in global_work_offset for any dimensions is greater than the
        // maximum value representable by size t on the device on which the kernel-instance
        // will be enqueued
        if u64::checked_add(gws as u64, gwo as u64)
            .filter(|&x| x <= device_max)
            .is_none()
        {
            return Err(CL_INVALID_GLOBAL_OFFSET);
        }
    }

    // If global_work_size is NULL, or the value in any passed dimension is 0 then the kernel
    // command will trivially succeed after its event dependencies are satisfied and subsequently
    // update its completion event.
    let cb: EventSig = if global_work_size.contains(&0) {
        Box::new(|_, _| Ok(()))
    } else {
        k.launch(
            &q,
            work_dim,
            local_work_size,
            global_work_size,
            global_work_offset,
        )?
    };

    create_and_queue(q, CL_COMMAND_NDRANGE_KERNEL, evs, event, false, cb)

    //• CL_INVALID_WORK_GROUP_SIZE if local_work_size is specified and is not consistent with the required number of sub-groups for kernel in the program source.
    //• CL_INVALID_WORK_GROUP_SIZE if local_work_size is specified and the total number of work-items in the work-group computed as local_work_size[0] × … local_work_size[work_dim - 1] is greater than the value specified by CL_KERNEL_WORK_GROUP_SIZE in the Kernel Object Device Queries table.
    //• CL_MISALIGNED_SUB_BUFFER_OFFSET if a sub-buffer object is specified as the value for an argument that is a buffer object and the offset specified when the sub-buffer object is created is not aligned to CL_DEVICE_MEM_BASE_ADDR_ALIGN value for device associated with queue. This error code
    //• CL_INVALID_IMAGE_SIZE if an image object is specified as an argument value and the image dimensions (image width, height, specified or compute row and/or slice pitch) are not supported by device associated with queue.
    //• CL_IMAGE_FORMAT_NOT_SUPPORTED if an image object is specified as an argument value and the image format (image channel order and data type) is not supported by device associated with queue.
    //• CL_OUT_OF_RESOURCES if there is a failure to queue the execution instance of kernel on the command-queue because of insufficient resources needed to execute the kernel. For example, the explicitly specified local_work_size causes a failure to execute the kernel because of insufficient resources such as registers or local memory. Another example would be the number of read-only image args used in kernel exceed the CL_DEVICE_MAX_READ_IMAGE_ARGS value for device or the number of write-only and read-write image args used in kernel exceed the CL_DEVICE_MAX_READ_WRITE_IMAGE_ARGS value for device or the number of samplers used in kernel exceed CL_DEVICE_MAX_SAMPLERS for device.
    //• CL_MEM_OBJECT_ALLOCATION_FAILURE if there is a failure to allocate memory for data store associated with image or buffer objects specified as arguments to kernel.
    //• CL_INVALID_OPERATION if SVM pointers are passed as arguments to a kernel and the device does not support SVM or if system pointers are passed as arguments to a kernel and/or stored inside SVM allocations passed as kernel arguments and the device does not support fine grain system SVM allocations.
}

pub fn enqueue_task(
    command_queue: cl_command_queue,
    kernel: cl_kernel,
    num_events_in_wait_list: cl_uint,
    event_wait_list: *const cl_event,
    event: *mut cl_event,
) -> CLResult<()> {
    // clEnqueueTask is equivalent to calling clEnqueueNDRangeKernel with work_dim set to 1,
    // global_work_offset set to NULL, global_work_size[0] set to 1, and local_work_size[0] set to
    // 1.
    enqueue_ndrange_kernel(
        command_queue,
        kernel,
        1,
        ptr::null(),
        [1, 1, 1].as_ptr(),
        [1, 0, 0].as_ptr(),
        num_events_in_wait_list,
        event_wait_list,
        event,
    )
}

pub fn clone_kernel(source_kernel: cl_kernel) -> CLResult<cl_kernel> {
    let k = source_kernel.get_ref()?;
    Ok(cl_kernel::from_arc(Arc::new(k.clone())))
}