// Copyright 2023 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build playstation5

package playstation5

// #include "graphics_playstation5.h"
import "C"

import (
	"fmt"
	"runtime"
	"unsafe"

	"github.com/hajimehoshi/ebiten/v2/internal/graphics"
	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
)

type playstation5Error struct {
	name    string
	code    int
	message string
}

func newPlaystation5Error(name string, err C.ebitengine_Error) *playstation5Error {
	return &playstation5Error{
		name:    name,
		code:    int(err.code),
		message: C.GoString(err.message),
	}
}

func (e *playstation5Error) Error() string {
	return fmt.Sprintf("playstation5: error at %s, code: %d, message: %s", e.name, e.code, e.message)
}

type Graphics struct {
}

func NewGraphics() (*Graphics, error) {
	return &Graphics{}, nil
}

func (g *Graphics) Initialize() error {
	if err := C.ebitengine_InitializeGraphics(); !C.ebitengine_IsErrorNil(&err) {
		return newPlaystation5Error("(*playstation5.Graphics).Initialize", err)
	}
	return nil
}

func (g *Graphics) Begin() error {
	C.ebitengine_Begin()
	return nil
}

func (g *Graphics) End(present bool) error {
	var cPresent C.int
	if present {
		cPresent = 1
	}
	C.ebitengine_End(cPresent)
	return nil
}

func (g *Graphics) SetTransparent(transparent bool) {
}

func (g *Graphics) SetVertices(vertices []float32, indices []uint32) error {
	defer runtime.KeepAlive(vertices)
	defer runtime.KeepAlive(indices)
	C.ebitengine_SetVertices((*C.float)(unsafe.SliceData(vertices)), C.int(len(vertices)), (*C.uint32_t)(unsafe.SliceData(indices)), C.int(len(indices)))
	return nil
}

func (g *Graphics) NewImage(width, height int) (graphicsdriver.Image, error) {
	var id C.int
	width = graphics.InternalImageSize(width)
	height = graphics.InternalImageSize(height)
	if err := C.ebitengine_NewImage(&id, C.int(width), C.int(height)); !C.ebitengine_IsErrorNil(&err) {
		return nil, newPlaystation5Error("(*playstation5.Graphics).NewImage", err)
	}
	return &Image{
		id: graphicsdriver.ImageID(id),
	}, nil
}

func (g *Graphics) NewScreenFramebufferImage(width, height int) (graphicsdriver.Image, error) {
	var id C.int
	if err := C.ebitengine_NewScreenFramebufferImage(&id, C.int(width), C.int(height)); !C.ebitengine_IsErrorNil(&err) {
		return nil, newPlaystation5Error("(*playstation5.Graphics).NewScreenFramebufferImage", err)
	}
	return &Image{
		id: graphicsdriver.ImageID(id),
	}, nil
}

func (g *Graphics) SetVsyncEnabled(enabled bool) {
}

func (g *Graphics) NeedsClearingScreen() bool {
	return true
}

func (g *Graphics) MaxImageSize() int {
	return 4096 // TODO: Get the value from the SDK.
}

func (g *Graphics) NewShader(program *shaderir.Program) (graphicsdriver.Shader, error) {
	s := precompiledShaders[program.SourceHash]
	ps := C.ebitengine_PrecompiledShader{
		vertex_header:      (*C.char)(unsafe.Pointer(unsafe.SliceData(s.vertexHeader))),
		vertex_header_size: C.int(len(s.vertexHeader)),
		vertex_text:        (*C.char)(unsafe.Pointer(unsafe.SliceData(s.vertexText))),
		vertex_text_size:   C.int(len(s.vertexText)),
		pixel_header:       (*C.char)(unsafe.Pointer(unsafe.SliceData(s.pixelHeader))),
		pixel_header_size:  C.int(len(s.pixelHeader)),
		pixel_text:         (*C.char)(unsafe.Pointer(unsafe.SliceData(s.pixelText))),
		pixel_text_size:    C.int(len(s.pixelText)),
	}

	var id C.int
	if err := C.ebitengine_NewShader(&id, &ps); !C.ebitengine_IsErrorNil(&err) {
		return nil, newPlaystation5Error("(*playstation5.Graphics).NewShader", err)
	}
	return &Shader{
		id: graphicsdriver.ShaderID(id),
	}, nil
}

func (g *Graphics) DrawTriangles(dst graphicsdriver.ImageID, srcs [graphics.ShaderSrcImageCount]graphicsdriver.ImageID, shader graphicsdriver.ShaderID, dstRegions []graphicsdriver.DstRegion, indexOffset int, blend graphicsdriver.Blend, uniforms []uint32, fillRule graphicsdriver.FillRule) error {
	cSrcs := make([]C.int, len(srcs))
	for i, src := range srcs {
		cSrcs[i] = C.int(src)
	}
	defer runtime.KeepAlive(cSrcs)

	cDstRegions := make([]C.ebitengine_DstRegion, len(dstRegions))
	defer runtime.KeepAlive(cDstRegions)
	for i, r := range dstRegions {
		cDstRegions[i] = C.ebitengine_DstRegion{
			min_x:       C.int(r.Region.Min.X),
			min_y:       C.int(r.Region.Min.Y),
			max_x:       C.int(r.Region.Max.X),
			max_y:       C.int(r.Region.Max.Y),
			index_count: C.int(r.IndexCount),
		}
	}

	cBlend := C.ebitengine_Blend{
		factor_src_rgb:   C.uint8_t(blend.BlendFactorSourceRGB),
		factor_src_alpha: C.uint8_t(blend.BlendFactorSourceAlpha),
		factor_dst_rgb:   C.uint8_t(blend.BlendFactorDestinationRGB),
		factor_dst_alpha: C.uint8_t(blend.BlendFactorDestinationAlpha),
		operation_rgb:    C.uint8_t(blend.BlendOperationRGB),
		operation_alpha:  C.uint8_t(blend.BlendOperationAlpha),
	}

	cUniforms := make([]C.uint32_t, len(uniforms))
	defer runtime.KeepAlive(cUniforms)
	for i, u := range uniforms {
		cUniforms[i] = C.uint32_t(u)
	}

	if err := C.ebitengine_DrawTriangles(C.int(dst), unsafe.SliceData(cSrcs), C.int(len(cSrcs)), C.int(shader), unsafe.SliceData(cDstRegions), C.int(len(cDstRegions)), C.int(indexOffset), cBlend, unsafe.SliceData(cUniforms), C.int(len(cUniforms)), C.int(fillRule)); !C.ebitengine_IsErrorNil(&err) {
		return newPlaystation5Error("(*playstation5.Graphics).DrawTriangles", err)
	}
	return nil
}

type Image struct {
	id graphicsdriver.ImageID
}

func (i *Image) ID() graphicsdriver.ImageID {
	return i.id
}

func (i *Image) Dispose() {
	C.ebitengine_DisposeImage(C.int(i.id))
}

func (i *Image) ReadPixels(args []graphicsdriver.PixelsArgs) error {
	for _, a := range args {
		region := C.ebitengine_Region{
			min_x: C.int(a.Region.Min.X),
			min_y: C.int(a.Region.Min.Y),
			max_x: C.int(a.Region.Max.X),
			max_y: C.int(a.Region.Max.Y),
		}
		C.ebitengine_ReadPixels(C.int(i.id), (*C.uint8_t)(unsafe.Pointer(unsafe.SliceData(a.Pixels))), region)
	}
	if err := C.ebitengine_FlushReadPixels(C.int(i.id)); !C.ebitengine_IsErrorNil(&err) {
		return newPlaystation5Error("(*playstation5.Image).ReadPixels", err)
	}
	return nil
}

func (i *Image) WritePixels(args []graphicsdriver.PixelsArgs) error {
	for _, a := range args {
		region := C.ebitengine_Region{
			min_x: C.int(a.Region.Min.X),
			min_y: C.int(a.Region.Min.Y),
			max_x: C.int(a.Region.Max.X),
			max_y: C.int(a.Region.Max.Y),
		}
		C.ebitengine_WritePixels(C.int(i.id), (*C.uint8_t)(unsafe.Pointer(unsafe.SliceData(a.Pixels))), region)
	}
	if err := C.ebitengine_FlushWritePixels(C.int(i.id)); !C.ebitengine_IsErrorNil(&err) {
		return newPlaystation5Error("(*playstation5.Image).WritePixels", err)
	}
	return nil
}

type Shader struct {
	id graphicsdriver.ShaderID
}

func (s *Shader) ID() graphicsdriver.ShaderID {
	return s.id
}

func (s *Shader) Dispose() {
	C.ebitengine_DisposeShader(C.int(s.id))
}