use crate::api::icd::*;
use crate::core::context::*;
use crate::core::device::*;
use crate::core::kernel::*;
use crate::core::platform::Platform;
use crate::impl_cl_type_trait;

use mesa_rust::compiler::clc::spirv::SPIRVBin;
use mesa_rust::compiler::clc::*;
use mesa_rust::compiler::nir::*;
use mesa_rust::util::disk_cache::*;
use mesa_rust_gen::*;
use rusticl_opencl_gen::*;

use std::collections::HashMap;
use std::collections::HashSet;
use std::ffi::CString;
use std::mem::size_of;
use std::ptr;
use std::slice;
use std::sync::atomic::AtomicU32;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use std::sync::Mutex;
use std::sync::MutexGuard;
use std::sync::Once;

const BIN_HEADER_SIZE_V1: usize =
    // 1. format version
    size_of::<u32>() +
    // 2. spirv len
    size_of::<u32>() +
    // 3. binary_type
    size_of::<cl_program_binary_type>();

const BIN_HEADER_SIZE: usize = BIN_HEADER_SIZE_V1;

// kernel cache
static mut DISK_CACHE: Option<DiskCache> = None;
static DISK_CACHE_ONCE: Once = Once::new();

fn get_disk_cache() -> &'static Option<DiskCache> {
    unsafe {
        DISK_CACHE_ONCE.call_once(|| {
            DISK_CACHE = DiskCache::new("rusticl", "rusticl", 0);
        });
        &DISK_CACHE
    }
}

pub enum ProgramSourceType {
    Binary,
    Linked,
    Src(CString),
    Il(spirv::SPIRVBin),
}

#[repr(C)]
pub struct Program {
    pub base: CLObjectBase<CL_INVALID_PROGRAM>,
    pub context: Arc<Context>,
    pub devs: Vec<Arc<Device>>,
    pub src: ProgramSourceType,
    pub kernel_count: AtomicU32,
    build: Mutex<ProgramBuild>,
}

impl_cl_type_trait!(cl_program, Program, CL_INVALID_PROGRAM);

#[derive(Clone)]
pub struct NirKernelBuild {
    pub nirs: HashMap<Arc<Device>, Arc<NirShader>>,
    pub args: Vec<KernelArg>,
    pub internal_args: Vec<InternalKernelArg>,
    pub attributes_string: String,
}

pub(super) struct ProgramBuild {
    builds: HashMap<Arc<Device>, ProgramDevBuild>,
    spec_constants: HashMap<u32, nir_const_value>,
    kernels: Vec<String>,
    kernel_builds: HashMap<String, NirKernelBuild>,
}

impl ProgramBuild {
    fn attribute_str(&self, kernel: &str, d: &Arc<Device>) -> String {
        let info = self.dev_build(d);

        let attributes_strings = [
            info.spirv.as_ref().unwrap().vec_type_hint(kernel),
            info.spirv.as_ref().unwrap().local_size(kernel),
            info.spirv.as_ref().unwrap().local_size_hint(kernel),
        ];

        let attributes_strings: Vec<_> = attributes_strings
            .iter()
            .flatten()
            .map(String::as_str)
            .collect();
        attributes_strings.join(",")
    }

    fn args(&self, dev: &Arc<Device>, kernel: &str) -> Vec<spirv::SPIRVKernelArg> {
        self.dev_build(dev).spirv.as_ref().unwrap().args(kernel)
    }

    fn build_nirs(&mut self, is_src: bool) {
        for kernel_name in &self.kernels {
            let kernel_args: HashSet<_> = self
                .devs_with_build()
                .iter()
                .map(|d| self.args(d, kernel_name))
                .collect();

            let args = kernel_args.into_iter().next().unwrap();
            let mut nirs = HashMap::new();
            let mut args_set = HashSet::new();
            let mut internal_args_set = HashSet::new();
            let mut attributes_string_set = HashSet::new();

            // TODO: we could run this in parallel?
            for d in self.devs_with_build() {
                let (nir, args, internal_args) = convert_spirv_to_nir(self, kernel_name, &args, d);
                let attributes_string = self.attribute_str(kernel_name, d);
                nirs.insert(d.clone(), Arc::new(nir));
                args_set.insert(args);
                internal_args_set.insert(internal_args);
                attributes_string_set.insert(attributes_string);
            }

            // we want the same (internal) args for every compiled kernel, for now
            assert!(args_set.len() == 1);
            assert!(internal_args_set.len() == 1);
            assert!(attributes_string_set.len() == 1);
            let args = args_set.into_iter().next().unwrap();
            let internal_args = internal_args_set.into_iter().next().unwrap();

            // spec: For kernels not created from OpenCL C source and the clCreateProgramWithSource
            // API call the string returned from this query [CL_KERNEL_ATTRIBUTES] will be empty.
            let attributes_string = if is_src {
                attributes_string_set.into_iter().next().unwrap()
            } else {
                String::new()
            };

            self.kernel_builds.insert(
                kernel_name.clone(),
                NirKernelBuild {
                    nirs: nirs,
                    args: args,
                    internal_args: internal_args,
                    attributes_string: attributes_string,
                },
            );
        }
    }

    fn dev_build(&self, dev: &Device) -> &ProgramDevBuild {
        self.builds.get(dev).unwrap()
    }

    fn dev_build_mut(&mut self, dev: &Device) -> &mut ProgramDevBuild {
        self.builds.get_mut(dev).unwrap()
    }

    fn devs_with_build(&self) -> Vec<&Arc<Device>> {
        self.builds
            .iter()
            .filter(|(_, build)| build.status == CL_BUILD_SUCCESS as cl_build_status)
            .map(|(d, _)| d)
            .collect()
    }

    pub fn hash_key(&self, dev: &Arc<Device>, name: &str) -> Option<cache_key> {
        if let Some(cache) = dev.screen().shader_cache() {
            let info = self.dev_build(dev);
            assert_eq!(info.status, CL_BUILD_SUCCESS as cl_build_status);

            let spirv = info.spirv.as_ref().unwrap();
            let mut bin = spirv.to_bin().to_vec();
            bin.extend_from_slice(name.as_bytes());

            for (k, v) in &self.spec_constants {
                bin.extend_from_slice(&k.to_ne_bytes());
                unsafe {
                    // SAFETY: we fully initialize this union
                    bin.extend_from_slice(&v.u64_.to_ne_bytes());
                }
            }

            Some(cache.gen_key(&bin))
        } else {
            None
        }
    }

    pub fn to_nir(&self, kernel: &str, d: &Arc<Device>) -> NirShader {
        let mut spec_constants: Vec<_> = self
            .spec_constants
            .iter()
            .map(|(&id, &value)| nir_spirv_specialization {
                id: id,
                value: value,
                defined_on_module: true,
            })
            .collect();

        let info = self.dev_build(d);
        assert_eq!(info.status, CL_BUILD_SUCCESS as cl_build_status);

        let mut log = Platform::dbg().program.then(Vec::new);
        let nir = info.spirv.as_ref().unwrap().to_nir(
            kernel,
            d.screen
                .nir_shader_compiler_options(pipe_shader_type::PIPE_SHADER_COMPUTE),
            &d.lib_clc,
            &mut spec_constants,
            d.address_bits(),
            log.as_mut(),
        );

        if let Some(log) = log {
            for line in log {
                eprintln!("{}", line);
            }
        };

        nir.unwrap()
    }
}

struct ProgramDevBuild {
    spirv: Option<spirv::SPIRVBin>,
    status: cl_build_status,
    options: String,
    log: String,
    bin_type: cl_program_binary_type,
}

fn prepare_options(options: &str, dev: &Device) -> Vec<CString> {
    let mut options = options.to_owned();
    if !options.contains("-cl-std=CL") {
        options.push_str(" -cl-std=CL");
        options.push_str(dev.clc_version.api_str());
    }
    if !dev.image_supported() {
        options.push_str(" -U__IMAGE_SUPPORT__");
    }
    options.push_str(" -D__OPENCL_VERSION__=");
    options.push_str(dev.cl_version.clc_str());

    let mut res = Vec::new();

    // we seperate on a ' ' unless we hit a "
    let mut sep = ' ';
    let mut old = 0;
    for (i, c) in options.char_indices() {
        if c == '"' {
            if sep == ' ' {
                sep = '"';
            } else {
                sep = ' ';
            }
        }

        if c == '"' || c == sep {
            // beware of double seps
            if old != i {
                res.push(&options[old..i]);
            }
            old = i + c.len_utf8();
        }
    }
    // add end of the string
    res.push(&options[old..]);

    res.iter()
        .map(|&a| match a {
            "-cl-denorms-are-zero" => "-fdenormal-fp-math=positive-zero",
            _ => a,
        })
        .map(CString::new)
        .map(Result::unwrap)
        .collect()
}

impl Program {
    fn create_default_builds(devs: &[Arc<Device>]) -> HashMap<Arc<Device>, ProgramDevBuild> {
        devs.iter()
            .map(|d| {
                (
                    d.clone(),
                    ProgramDevBuild {
                        spirv: None,
                        status: CL_BUILD_NONE,
                        log: String::from(""),
                        options: String::from(""),
                        bin_type: CL_PROGRAM_BINARY_TYPE_NONE,
                    },
                )
            })
            .collect()
    }

    pub fn new(context: &Arc<Context>, devs: &[Arc<Device>], src: CString) -> Arc<Program> {
        Arc::new(Self {
            base: CLObjectBase::new(),
            context: context.clone(),
            devs: devs.to_vec(),
            src: ProgramSourceType::Src(src),
            kernel_count: AtomicU32::new(0),
            build: Mutex::new(ProgramBuild {
                builds: Self::create_default_builds(devs),
                spec_constants: HashMap::new(),
                kernels: Vec::new(),
                kernel_builds: HashMap::new(),
            }),
        })
    }

    pub fn from_bins(
        context: Arc<Context>,
        devs: Vec<Arc<Device>>,
        bins: &[&[u8]],
    ) -> Arc<Program> {
        let mut builds = HashMap::new();
        let mut kernels = HashSet::new();

        for (d, b) in devs.iter().zip(bins) {
            let mut ptr = b.as_ptr();
            let bin_type;
            let spirv;

            unsafe {
                // 1. version
                let version = ptr.cast::<u32>().read();
                ptr = ptr.add(size_of::<u32>());

                match version {
                    1 => {
                        // 2. size of the spirv
                        let spirv_size = ptr.cast::<u32>().read();
                        ptr = ptr.add(size_of::<u32>());

                        // 3. binary_type
                        bin_type = ptr.cast::<cl_program_binary_type>().read();
                        ptr = ptr.add(size_of::<cl_program_binary_type>());

                        // 4. the spirv
                        assert!(b.as_ptr().add(BIN_HEADER_SIZE_V1) == ptr);
                        assert!(b.len() == BIN_HEADER_SIZE_V1 + spirv_size as usize);
                        spirv = Some(spirv::SPIRVBin::from_bin(slice::from_raw_parts(
                            ptr,
                            spirv_size as usize,
                        )));
                    }
                    _ => panic!("unknown version"),
                }
            }

            if let Some(spirv) = &spirv {
                for k in spirv.kernels() {
                    kernels.insert(k);
                }
            }

            builds.insert(
                d.clone(),
                ProgramDevBuild {
                    spirv: spirv,
                    status: CL_BUILD_SUCCESS as cl_build_status,
                    log: String::from(""),
                    options: String::from(""),
                    bin_type: bin_type,
                },
            );
        }

        let mut build = ProgramBuild {
            builds: builds,
            spec_constants: HashMap::new(),
            kernels: kernels.into_iter().collect(),
            kernel_builds: HashMap::new(),
        };
        build.build_nirs(false);

        Arc::new(Self {
            base: CLObjectBase::new(),
            context: context,
            devs: devs,
            src: ProgramSourceType::Binary,
            kernel_count: AtomicU32::new(0),
            build: Mutex::new(build),
        })
    }

    pub fn from_spirv(context: Arc<Context>, spirv: &[u8]) -> Arc<Program> {
        let builds = Self::create_default_builds(&context.devs);
        Arc::new(Self {
            base: CLObjectBase::new(),
            devs: context.devs.clone(),
            context: context,
            src: ProgramSourceType::Il(SPIRVBin::from_bin(spirv)),
            kernel_count: AtomicU32::new(0),
            build: Mutex::new(ProgramBuild {
                builds: builds,
                spec_constants: HashMap::new(),
                kernels: Vec::new(),
                kernel_builds: HashMap::new(),
            }),
        })
    }

    fn build_info(&self) -> MutexGuard<ProgramBuild> {
        self.build.lock().unwrap()
    }

    pub fn get_nir_kernel_build(&self, name: &str) -> NirKernelBuild {
        let info = self.build_info();
        info.kernel_builds.get(name).unwrap().clone()
    }

    pub fn status(&self, dev: &Arc<Device>) -> cl_build_status {
        self.build_info().dev_build(dev).status
    }

    pub fn log(&self, dev: &Arc<Device>) -> String {
        self.build_info().dev_build(dev).log.clone()
    }

    pub fn bin_type(&self, dev: &Arc<Device>) -> cl_program_binary_type {
        self.build_info().dev_build(dev).bin_type
    }

    pub fn options(&self, dev: &Arc<Device>) -> String {
        self.build_info().dev_build(dev).options.clone()
    }

    // we need to precalculate the size
    pub fn bin_sizes(&self) -> Vec<usize> {
        let lock = self.build_info();
        let mut res = Vec::new();
        for d in &self.devs {
            let info = lock.dev_build(d);

            res.push(
                info.spirv
                    .as_ref()
                    .map_or(0, |s| s.to_bin().len() + BIN_HEADER_SIZE),
            );
        }
        res
    }

    pub fn binaries(&self, vals: &[u8]) -> Vec<*mut u8> {
        // if the application didn't provide any pointers, just return the length of devices
        if vals.is_empty() {
            return vec![std::ptr::null_mut(); self.devs.len()];
        }

        // vals is an array of pointers where we should write the device binaries into
        if vals.len() != self.devs.len() * size_of::<*const u8>() {
            panic!("wrong size")
        }

        let ptrs: &[*mut u8] = unsafe {
            slice::from_raw_parts(vals.as_ptr().cast(), vals.len() / size_of::<*mut u8>())
        };

        let lock = self.build_info();
        for (i, d) in self.devs.iter().enumerate() {
            let mut ptr = ptrs[i];
            let info = lock.dev_build(d);
            let spirv = info.spirv.as_ref().unwrap().to_bin();

            unsafe {
                // 1. binary format version
                ptr.cast::<u32>().write(1);
                ptr = ptr.add(size_of::<u32>());

                // 2. size of the spirv
                ptr.cast::<u32>().write(spirv.len() as u32);
                ptr = ptr.add(size_of::<u32>());

                // 3. binary_type
                ptr.cast::<cl_program_binary_type>().write(info.bin_type);
                ptr = ptr.add(size_of::<cl_program_binary_type>());

                // 4. the spirv
                assert!(ptrs[i].add(BIN_HEADER_SIZE) == ptr);
                ptr::copy_nonoverlapping(spirv.as_ptr(), ptr, spirv.len());
            }
        }

        ptrs.to_vec()
    }

    pub fn kernel_signatures(&self, kernel_name: &str) -> HashSet<Vec<spirv::SPIRVKernelArg>> {
        let build = self.build_info();
        let devs = build.devs_with_build();

        if devs.is_empty() {
            return HashSet::new();
        }

        devs.iter().map(|d| build.args(d, kernel_name)).collect()
    }

    pub fn kernels(&self) -> Vec<String> {
        self.build_info().kernels.clone()
    }

    pub fn active_kernels(&self) -> bool {
        self.kernel_count.load(Ordering::Relaxed) != 0
    }

    pub fn build(&self, dev: &Arc<Device>, options: String) -> bool {
        let lib = options.contains("-create-library");
        let mut info = self.build_info();
        if !self.do_compile(dev, options, &Vec::new(), &mut info) {
            return false;
        }

        let mut d = info.dev_build_mut(dev);
        let spirvs = [d.spirv.as_ref().unwrap()];
        let (spirv, log) = spirv::SPIRVBin::link(&spirvs, lib);

        d.log.push_str(&log);
        d.spirv = spirv;
        if let Some(spirv) = &d.spirv {
            d.bin_type = if lib {
                CL_PROGRAM_BINARY_TYPE_LIBRARY
            } else {
                CL_PROGRAM_BINARY_TYPE_EXECUTABLE
            };
            d.status = CL_BUILD_SUCCESS as cl_build_status;
            let mut kernels = spirv.kernels();
            info.kernels.append(&mut kernels);
            info.build_nirs(self.is_src());
            true
        } else {
            d.status = CL_BUILD_ERROR;
            d.bin_type = CL_PROGRAM_BINARY_TYPE_NONE;
            false
        }
    }

    fn do_compile(
        &self,
        dev: &Arc<Device>,
        options: String,
        headers: &[spirv::CLCHeader],
        info: &mut MutexGuard<ProgramBuild>,
    ) -> bool {
        let mut d = info.dev_build_mut(dev);

        let (spirv, log) = match &self.src {
            ProgramSourceType::Il(spirv) => spirv.clone_on_validate(),
            ProgramSourceType::Src(src) => {
                let args = prepare_options(&options, dev);
                spirv::SPIRVBin::from_clc(
                    src,
                    &args,
                    headers,
                    get_disk_cache(),
                    dev.cl_features(),
                    &dev.spirv_extensions,
                    dev.address_bits(),
                )
            }
            // do nothing if we got a library or binary
            _ => {
                return true;
            }
        };

        d.spirv = spirv;
        d.log = log;
        d.options = options;

        if d.spirv.is_some() {
            d.status = CL_BUILD_SUCCESS as cl_build_status;
            d.bin_type = CL_PROGRAM_BINARY_TYPE_COMPILED_OBJECT;
            true
        } else {
            d.status = CL_BUILD_ERROR;
            false
        }
    }

    pub fn compile(
        &self,
        dev: &Arc<Device>,
        options: String,
        headers: &[spirv::CLCHeader],
    ) -> bool {
        self.do_compile(dev, options, headers, &mut self.build_info())
    }

    pub fn link(
        context: Arc<Context>,
        devs: &[Arc<Device>],
        progs: &[Arc<Program>],
        options: String,
    ) -> Arc<Program> {
        let devs: Vec<Arc<Device>> = devs.iter().map(|d| (*d).clone()).collect();
        let mut builds = HashMap::new();
        let mut kernels = HashSet::new();
        let mut locks: Vec<_> = progs.iter().map(|p| p.build_info()).collect();
        let lib = options.contains("-create-library");

        for d in &devs {
            let bins: Vec<_> = locks
                .iter_mut()
                .map(|l| l.dev_build(d).spirv.as_ref().unwrap())
                .collect();

            let (spirv, log) = spirv::SPIRVBin::link(&bins, lib);

            let status;
            let bin_type;
            if let Some(spirv) = &spirv {
                for k in spirv.kernels() {
                    kernels.insert(k);
                }
                status = CL_BUILD_SUCCESS as cl_build_status;
                bin_type = if lib {
                    CL_PROGRAM_BINARY_TYPE_LIBRARY
                } else {
                    CL_PROGRAM_BINARY_TYPE_EXECUTABLE
                };
            } else {
                status = CL_BUILD_ERROR;
                bin_type = CL_PROGRAM_BINARY_TYPE_NONE;
            };

            builds.insert(
                d.clone(),
                ProgramDevBuild {
                    spirv: spirv,
                    status: status,
                    log: log,
                    options: String::from(""),
                    bin_type: bin_type,
                },
            );
        }

        let mut build = ProgramBuild {
            builds: builds,
            spec_constants: HashMap::new(),
            kernels: kernels.into_iter().collect(),
            kernel_builds: HashMap::new(),
        };

        // Pre build nir kernels
        build.build_nirs(false);

        Arc::new(Self {
            base: CLObjectBase::new(),
            context: context,
            devs: devs,
            src: ProgramSourceType::Linked,
            kernel_count: AtomicU32::new(0),
            build: Mutex::new(build),
        })
    }

    pub fn is_il(&self) -> bool {
        matches!(self.src, ProgramSourceType::Il(_))
    }

    pub fn is_src(&self) -> bool {
        matches!(self.src, ProgramSourceType::Src(_))
    }

    pub fn get_spec_constant_size(&self, spec_id: u32) -> u8 {
        match &self.src {
            ProgramSourceType::Il(il) => il
                .spec_constant(spec_id)
                .map_or(0, spirv::CLCSpecConstantType::size),
            _ => unreachable!(),
        }
    }

    pub fn set_spec_constant(&self, spec_id: u32, data: &[u8]) {
        let mut lock = self.build_info();
        let mut val = nir_const_value::default();

        match data.len() {
            1 => val.u8_ = u8::from_ne_bytes(data.try_into().unwrap()),
            2 => val.u16_ = u16::from_ne_bytes(data.try_into().unwrap()),
            4 => val.u32_ = u32::from_ne_bytes(data.try_into().unwrap()),
            8 => val.u64_ = u64::from_ne_bytes(data.try_into().unwrap()),
            _ => unreachable!("Spec constant with invalid size!"),
        };

        lock.spec_constants.insert(spec_id, val);
    }
}