/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use crate::{
    device::{DeviceError, HostMap, MissingFeatures},
    hub::Resource,
    id::{DeviceId, SwapChainId, TextureId},
    memory_init_tracker::MemoryInitTracker,
    track::{TextureSelector, DUMMY_SELECTOR},
    validation::MissingBufferUsageError,
    Label, LifeGuard, RefCount, Stored,
};

use thiserror::Error;

use std::{borrow::Borrow, num::NonZeroU8, ops::Range, ptr::NonNull};

#[repr(C)]
#[derive(Debug)]
pub enum BufferMapAsyncStatus {
    Success,
    Error,
    Aborted,
    Unknown,
    ContextLost,
}

#[derive(Debug)]
pub(crate) enum BufferMapState<A: hal::Api> {
    /// Mapped at creation.
    Init {
        ptr: NonNull<u8>,
        stage_buffer: A::Buffer,
        needs_flush: bool,
    },
    /// Waiting for GPU to be done before mapping
    Waiting(BufferPendingMapping),
    /// Mapped
    Active {
        ptr: NonNull<u8>,
        range: hal::MemoryRange,
        host: HostMap,
    },
    /// Not mapped
    Idle,
}

unsafe impl<A: hal::Api> Send for BufferMapState<A> {}
unsafe impl<A: hal::Api> Sync for BufferMapState<A> {}

pub type BufferMapCallback = unsafe extern "C" fn(status: BufferMapAsyncStatus, userdata: *mut u8);

#[repr(C)]
#[derive(Debug)]
pub struct BufferMapOperation {
    pub host: HostMap,
    pub callback: BufferMapCallback,
    pub user_data: *mut u8,
}

//TODO: clarify if/why this is needed here
unsafe impl Send for BufferMapOperation {}
unsafe impl Sync for BufferMapOperation {}

impl BufferMapOperation {
    pub(crate) fn call_error(self) {
        log::error!("wgpu_buffer_map_async failed: buffer mapping is pending");
        unsafe {
            (self.callback)(BufferMapAsyncStatus::Error, self.user_data);
        }
    }
}

#[derive(Clone, Debug, Error)]
pub enum BufferAccessError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("buffer is invalid")]
    Invalid,
    #[error("buffer is destroyed")]
    Destroyed,
    #[error("buffer is already mapped")]
    AlreadyMapped,
    #[error(transparent)]
    MissingBufferUsage(#[from] MissingBufferUsageError),
    #[error("buffer is not mapped")]
    NotMapped,
    #[error(
        "buffer map range must start aligned to `MAP_ALIGNMENT` and end to `COPY_BUFFER_ALIGNMENT`"
    )]
    UnalignedRange,
    #[error("buffer offset invalid: offset {offset} must be multiple of 8")]
    UnalignedOffset { offset: wgt::BufferAddress },
    #[error("buffer range size invalid: range_size {range_size} must be multiple of 4")]
    UnalignedRangeSize { range_size: wgt::BufferAddress },
    #[error("buffer access out of bounds: index {index} would underrun the buffer (limit: {min})")]
    OutOfBoundsUnderrun {
        index: wgt::BufferAddress,
        min: wgt::BufferAddress,
    },
    #[error(
        "buffer access out of bounds: last index {index} would overrun the buffer (limit: {max})"
    )]
    OutOfBoundsOverrun {
        index: wgt::BufferAddress,
        max: wgt::BufferAddress,
    },
}

#[derive(Debug)]
pub(crate) struct BufferPendingMapping {
    pub range: Range<wgt::BufferAddress>,
    pub op: BufferMapOperation,
    // hold the parent alive while the mapping is active
    pub parent_ref_count: RefCount,
}

pub type BufferDescriptor<'a> = wgt::BufferDescriptor<Label<'a>>;

#[derive(Debug)]
pub struct Buffer<A: hal::Api> {
    pub(crate) raw: Option<A::Buffer>,
    pub(crate) device_id: Stored<DeviceId>,
    pub(crate) is_coherent: bool,
    pub(crate) usage: wgt::BufferUsage,
    pub(crate) size: wgt::BufferAddress,
    pub(crate) initialization_status: MemoryInitTracker,
    pub(crate) sync_mapped_writes: Option<hal::MemoryRange>,
    pub(crate) life_guard: LifeGuard,
    pub(crate) map_state: BufferMapState<A>,
}

#[derive(Clone, Debug, Error)]
pub enum CreateBufferError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("failed to map buffer while creating: {0}")]
    AccessError(#[from] BufferAccessError),
    #[error("buffers that are mapped at creation have to be aligned to `COPY_BUFFER_ALIGNMENT`")]
    UnalignedSize,
    #[error("Buffers cannot have empty usage flags")]
    EmptyUsage,
    #[error("`MAP` usage can only be combined with the opposite `COPY`, requested {0:?}")]
    UsageMismatch(wgt::BufferUsage),
}

impl<A: hal::Api> Resource for Buffer<A> {
    const TYPE: &'static str = "Buffer";

    fn life_guard(&self) -> &LifeGuard {
        &self.life_guard
    }
}

impl<A: hal::Api> Borrow<()> for Buffer<A> {
    fn borrow(&self) -> &() {
        &DUMMY_SELECTOR
    }
}

pub type TextureDescriptor<'a> = wgt::TextureDescriptor<Label<'a>>;

#[derive(Debug)]
pub struct Texture<A: hal::Api> {
    pub(crate) raw: Option<A::Texture>,
    pub(crate) device_id: Stored<DeviceId>,
    pub(crate) desc: wgt::TextureDescriptor<()>,
    pub(crate) format_features: wgt::TextureFormatFeatures,
    pub(crate) full_range: TextureSelector,
    pub(crate) life_guard: LifeGuard,
}

#[derive(Clone, Copy, Debug)]
pub enum TextureErrorDimension {
    X,
    Y,
    Z,
}

#[derive(Clone, Debug, Error)]
pub enum TextureDimensionError {
    #[error("Dimension {0:?} is zero")]
    Zero(TextureErrorDimension),
    #[error("Dimension {0:?} value {given} exceeds the limit of {limit}")]
    LimitExceeded {
        dim: TextureErrorDimension,
        given: u32,
        limit: u32,
    },
    #[error("sample count {0} is invalid")]
    InvalidSampleCount(u32),
}

#[derive(Clone, Debug, Error)]
pub enum CreateTextureError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("D24Plus textures cannot be copied")]
    CannotCopyD24Plus,
    #[error("Textures cannot have empty usage flags")]
    EmptyUsage,
    #[error(transparent)]
    InvalidDimension(#[from] TextureDimensionError),
    #[error("texture descriptor mip level count ({0}) is invalid")]
    InvalidMipLevelCount(u32),
    #[error("The texture usages {0:?} are not allowed on a texture of type {1:?}")]
    InvalidUsages(wgt::TextureUsage, wgt::TextureFormat),
    #[error("Texture format {0:?} can't be used")]
    MissingFeatures(wgt::TextureFormat, #[source] MissingFeatures),
}

impl<A: hal::Api> Resource for Texture<A> {
    const TYPE: &'static str = "Texture";

    fn life_guard(&self) -> &LifeGuard {
        &self.life_guard
    }
}

impl<A: hal::Api> Borrow<TextureSelector> for Texture<A> {
    fn borrow(&self) -> &TextureSelector {
        &self.full_range
    }
}

/// Describes a [`TextureView`].
#[derive(Clone, Debug, Default, PartialEq)]
#[cfg_attr(feature = "trace", derive(serde::Serialize))]
#[cfg_attr(feature = "replay", derive(serde::Deserialize), serde(default))]
pub struct TextureViewDescriptor<'a> {
    /// Debug label of the texture view. This will show up in graphics debuggers for easy identification.
    pub label: Label<'a>,
    /// Format of the texture view, or `None` for the same format as the texture itself.
    /// At this time, it must be the same the underlying format of the texture.
    pub format: Option<wgt::TextureFormat>,
    /// The dimension of the texture view. For 1D textures, this must be `1D`. For 2D textures it must be one of
    /// `D2`, `D2Array`, `Cube`, and `CubeArray`. For 3D textures it must be `3D`
    pub dimension: Option<wgt::TextureViewDimension>,
    /// Range within the texture that is accessible via this view.
    pub range: wgt::ImageSubresourceRange,
}

#[derive(Debug)]
pub(crate) enum TextureViewSource {
    Native(Stored<TextureId>),
    SwapChain(Stored<SwapChainId>),
}

#[derive(Debug)]
pub(crate) struct HalTextureViewDescriptor {
    pub format: wgt::TextureFormat,
    pub dimension: wgt::TextureViewDimension,
    pub range: wgt::ImageSubresourceRange,
}

impl HalTextureViewDescriptor {
    pub fn aspects(&self) -> hal::FormatAspect {
        hal::FormatAspect::from(self.format) & hal::FormatAspect::from(self.range.aspect)
    }
}

#[derive(Debug)]
pub struct TextureView<A: hal::Api> {
    pub(crate) raw: A::TextureView,
    pub(crate) source: TextureViewSource,
    //TODO: store device_id for quick access?
    pub(crate) desc: HalTextureViewDescriptor,
    pub(crate) format_features: wgt::TextureFormatFeatures,
    pub(crate) extent: wgt::Extent3d,
    pub(crate) samples: u32,
    /// Internal use of this texture view when used as `BindingType::Texture`.
    pub(crate) sampled_internal_use: hal::TextureUse,
    pub(crate) selector: TextureSelector,
    pub(crate) life_guard: LifeGuard,
}

#[derive(Clone, Debug, Error)]
pub enum CreateTextureViewError {
    #[error("parent texture is invalid or destroyed")]
    InvalidTexture,
    #[error("not enough memory left")]
    OutOfMemory,
    #[error("Invalid texture view dimension `{view:?}` with texture of dimension `{texture:?}`")]
    InvalidTextureViewDimension {
        view: wgt::TextureViewDimension,
        texture: wgt::TextureDimension,
    },
    #[error("Invalid texture depth `{depth}` for texture view of dimension `Cubemap`. Cubemap views must use images of size 6.")]
    InvalidCubemapTextureDepth { depth: u32 },
    #[error("Invalid texture depth `{depth}` for texture view of dimension `CubemapArray`. Cubemap views must use images with sizes which are a multiple of 6.")]
    InvalidCubemapArrayTextureDepth { depth: u32 },
    #[error(
        "TextureView mip level count + base mip level {requested} must be <= Texture mip level count {total}"
    )]
    TooManyMipLevels { requested: u32, total: u32 },
    #[error("TextureView array layer count + base array layer {requested} must be <= Texture depth/array layer count {total}")]
    TooManyArrayLayers { requested: u32, total: u32 },
    #[error("Requested array layer count {requested} is not valid for the target view dimension {dim:?}")]
    InvalidArrayLayerCount {
        requested: u32,
        dim: wgt::TextureViewDimension,
    },
    #[error("Aspect {requested_aspect:?} is not in the source texture format {texture_format:?}")]
    InvalidAspect {
        texture_format: wgt::TextureFormat,
        requested_aspect: wgt::TextureAspect,
    },
    #[error("Unable to view texture {texture:?} as {view:?}")]
    FormatReinterpretation {
        texture: wgt::TextureFormat,
        view: wgt::TextureFormat,
    },
}

#[derive(Clone, Debug, Error)]
pub enum TextureViewDestroyError {
    #[error("cannot destroy swap chain image")]
    SwapChainImage,
}

impl<A: hal::Api> Resource for TextureView<A> {
    const TYPE: &'static str = "TextureView";

    fn life_guard(&self) -> &LifeGuard {
        &self.life_guard
    }
}

impl<A: hal::Api> Borrow<()> for TextureView<A> {
    fn borrow(&self) -> &() {
        &DUMMY_SELECTOR
    }
}

/// Describes a [`Sampler`]
#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "trace", derive(serde::Serialize))]
#[cfg_attr(feature = "replay", derive(serde::Deserialize))]
pub struct SamplerDescriptor<'a> {
    /// Debug label of the sampler. This will show up in graphics debuggers for easy identification.
    pub label: Label<'a>,
    /// How to deal with out of bounds accesses in the u (i.e. x) direction
    pub address_modes: [wgt::AddressMode; 3],
    /// How to filter the texture when it needs to be magnified (made larger)
    pub mag_filter: wgt::FilterMode,
    /// How to filter the texture when it needs to be minified (made smaller)
    pub min_filter: wgt::FilterMode,
    /// How to filter between mip map levels
    pub mipmap_filter: wgt::FilterMode,
    /// Minimum level of detail (i.e. mip level) to use
    pub lod_min_clamp: f32,
    /// Maximum level of detail (i.e. mip level) to use
    pub lod_max_clamp: f32,
    /// If this is enabled, this is a comparison sampler using the given comparison function.
    pub compare: Option<wgt::CompareFunction>,
    /// Valid values: 1, 2, 4, 8, and 16.
    pub anisotropy_clamp: Option<NonZeroU8>,
    /// Border color to use when address_mode is [`AddressMode::ClampToBorder`](wgt::AddressMode::ClampToBorder)
    pub border_color: Option<wgt::SamplerBorderColor>,
}

impl Default for SamplerDescriptor<'_> {
    fn default() -> Self {
        Self {
            label: None,
            address_modes: Default::default(),
            mag_filter: Default::default(),
            min_filter: Default::default(),
            mipmap_filter: Default::default(),
            lod_min_clamp: 0.0,
            lod_max_clamp: std::f32::MAX,
            compare: None,
            anisotropy_clamp: None,
            border_color: None,
        }
    }
}

#[derive(Debug)]
pub struct Sampler<A: hal::Api> {
    pub(crate) raw: A::Sampler,
    pub(crate) device_id: Stored<DeviceId>,
    pub(crate) life_guard: LifeGuard,
    /// `true` if this is a comparison sampler
    pub(crate) comparison: bool,
    /// `true` if this is a filtering sampler
    pub(crate) filtering: bool,
}

#[derive(Clone, Debug, Error)]
pub enum CreateSamplerError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("invalid anisotropic clamp {0}, must be one of 1, 2, 4, 8 or 16")]
    InvalidClamp(u8),
    #[error("cannot create any more samplers")]
    TooManyObjects,
    /// AddressMode::ClampToBorder requires feature ADDRESS_MODE_CLAMP_TO_BORDER.
    #[error(transparent)]
    MissingFeatures(#[from] MissingFeatures),
}

impl<A: hal::Api> Resource for Sampler<A> {
    const TYPE: &'static str = "Sampler";

    fn life_guard(&self) -> &LifeGuard {
        &self.life_guard
    }
}

impl<A: hal::Api> Borrow<()> for Sampler<A> {
    fn borrow(&self) -> &() {
        &DUMMY_SELECTOR
    }
}
#[derive(Clone, Debug, Error)]
pub enum CreateQuerySetError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("QuerySets cannot be made with zero queries")]
    ZeroCount,
    #[error("{count} is too many queries for a single QuerySet. QuerySets cannot be made more than {maximum} queries.")]
    TooManyQueries { count: u32, maximum: u32 },
    #[error(transparent)]
    MissingFeatures(#[from] MissingFeatures),
}

#[derive(Debug)]
pub struct QuerySet<A: hal::Api> {
    pub(crate) raw: A::QuerySet,
    pub(crate) device_id: Stored<DeviceId>,
    pub(crate) life_guard: LifeGuard,
    pub(crate) desc: wgt::QuerySetDescriptor,
}

impl<A: hal::Api> Resource for QuerySet<A> {
    const TYPE: &'static str = "QuerySet";

    fn life_guard(&self) -> &LifeGuard {
        &self.life_guard
    }
}

impl<A: hal::Api> Borrow<()> for QuerySet<A> {
    fn borrow(&self) -> &() {
        &DUMMY_SELECTOR
    }
}

#[derive(Clone, Debug, Error)]
pub enum DestroyError {
    #[error("resource is invalid")]
    Invalid,
    #[error("resource is already destroyed")]
    AlreadyDestroyed,
}