'use client'
import React, { useEffect, useRef, useState } from 'react'
import maplibregl, { CustomLayerInterface, CustomRenderMethodInput, } from 'maplibre-gl'
import 'maplibre-gl/dist/maplibre-gl.css'
import { useMap } from '@/app/map-context'
import { useMapLocation } from '@/hooks/use-map-location'
import { getSubdivisionRecommendation, detectPerformanceLevel, RegionMeshPresets } from '@/lib/tile-mesh'
import { createColorMap, ColorMapType, } from '@/lib/color-maps'
import { Colorbar } from './colorbar'
import { useRadarTile } from '@/hooks/use-radartile'
import { format, formatInTimeZone } from 'date-fns-tz'

interface MapComponentProps {
    style?: string
    center?: [number, number]
    zoom?: number
    imgBitmap?: ImageBitmap | null
    colorMapType?: ColorMapType
    onColorMapChange?: (type: ColorMapType) => void
}

export function MapComponent({
    style = 'https://api.maptiler.com/maps/019817f1-82a8-7f37-901d-4bedf68b27fb/style.json?key=hj3fxRdwF9KjEsBq8sYI',
    // style = 'https://api.maptiler.com/maps/landscape/style.json?key=hj3fxRdwF9KjEsBq8sYI',
    // style = 'https://api.maptiler.com/tiles/land-gradient-dark/tiles.json?key=hj3fxRdwF9KjEsBq8sYI',
    // center = [103.851959, 1.290270],
    // zoom = 11
    imgBitmap: propImgBitmap,
    colorMapType = 'meteorological',
    onColorMapChange
}: MapComponentProps) {

    const { fetchRadarTile, imgBitmap } = useRadarTile();
    const mapContainer = useRef<HTMLDivElement>(null)
    const { setMap, mapRef, currentDatetime, isMapReady } = useMap()
    const { location } = useMapLocation()
    const texRef = useRef<WebGLTexture | null>(null)
    const lutTexRef = useRef<WebGLTexture | null>(null)
    const glRef = useRef<WebGL2RenderingContext | null>(null)
    const customLayerRef = useRef<CustomGlLayer | null>(null)
    const [isReady, setIsReady] = useState<boolean>(false)
    const [currentColorMapType, setCurrentColorMapType] = useState<ColorMapType>(colorMapType)

    useEffect(() => {
        if (!isMapReady || !currentDatetime) return;
        const utc_time_str = formatInTimeZone(currentDatetime, 'UTC', 'yyyyMMddHHmmss')
        const new_url = `http://localhost:3050/api/v1/data?datetime=${utc_time_str}&area=cn`
        fetchRadarTile(new_url)
    }, [currentDatetime, isMapReady])

    useEffect(() => {
        if (!mapContainer.current) return

        const map = new maplibregl.Map({
            container: mapContainer.current,
            style: style,
            center: location.center,
            zoom: location.zoom,
            canvasContextAttributes: {
                contextType: 'webgl2',  // 请求 WebGL2
                antialias: true         // 打开多重采样抗锯齿
            }
        })

        map.on('style.load', () => {
            map.setProjection({
                type: 'globe'
            })

            const customGlLayer: CustomGlLayer = {
                id: 'player',
                type: 'custom',
                lastZoom: -1, // 添加缓存的缩放级别
                uniformLocations: {} as Record<string, WebGLUniformLocation | null>, // 缓存uniform位置

                prerender(gl: WebGLRenderingContext | WebGL2RenderingContext, { shaderData }: CustomRenderMethodInput) {


                    if (!this.program) {
                        glRef.current = gl as WebGL2RenderingContext;
                        if (!(gl instanceof WebGL2RenderingContext)) {
                            return;
                        }

                        const vertexSource = `#version 300 es

                            layout(location = 0) in vec2 a_pos;
                            layout(location = 1) in vec2 a_tex_coord;

                            ${shaderData.vertexShaderPrelude}
                            ${shaderData.define}

                            out vec2 v_tex_coord;
                    
                            void main() {
                                gl_Position = projectTile(a_pos);
                                v_tex_coord = a_tex_coord;
                            }`;

                        // WebGL2 fragment shader
                        const fragmentSource = `#version 300 es
                            precision highp float;
                            uniform sampler2D u_tex;
                            uniform sampler2D u_lut;

                            out vec4 fragColor;
                            in vec2 v_tex_coord;
                    
                            void main() {
                                vec4 texColor = texture(u_tex, v_tex_coord);
                                // 对于灰度图，RGB通道通常相同，取红色通道作为灰度值
                                float value = texColor.r * 3.4;

                                if (value < 0.07) {
                                    fragColor= vec4(1.0,1.0,1.0,0.2);
                                    return;
                                }

                                // normalizedValue = clamp(normalizedValue, 0.0, 1.0);
                                
                                // 使用 LUT 进行颜色映射
                                vec4 lutColor = texture(u_lut, vec2(value, 0.5));
                                // 添加一些透明度，使低值区域更透明
                                // float alpha = smoothstep(0.0, 0.1, value);
                                float alpha = 0.7;
                                fragColor = vec4(lutColor.rgb, alpha);
                                // fragColor = vec4(1.0,1.0,1.0,0.2);
                            }`

                        console.log(vertexSource, fragmentSource)

                        // Helper function to compile shader
                        const compileShader = (source: string, type: number): WebGLShader | null => {
                            const shader = gl.createShader(type);
                            if (!shader) return null;

                            gl.shaderSource(shader, source);
                            gl.compileShader(shader);

                            if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
                                console.error('Shader compile error:', gl.getShaderInfoLog(shader));
                                gl.deleteShader(shader);
                                return null;
                            }
                            return shader;
                        }

                        // Compile shaders
                        const vertexShader = compileShader(vertexSource, gl.VERTEX_SHADER);
                        const fragmentShader = compileShader(fragmentSource, gl.FRAGMENT_SHADER);

                        if (!vertexShader || !fragmentShader) return;

                        // Create and link program
                        const program = gl.createProgram();
                        if (!program) return;

                        gl.attachShader(program, vertexShader);
                        gl.attachShader(program, fragmentShader);
                        gl.linkProgram(program);

                        if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
                            console.error('Program link error:', gl.getProgramInfoLog(program));
                            return;
                        }

                        // Clean up shaders (they're now part of the program)
                        gl.deleteShader(vertexShader);
                        gl.deleteShader(fragmentShader);

                        this.program = program;

                        const tex = gl.createTexture()

                        if (!tex) {
                            console.error('Failed to create texture');
                            return;
                        }

                        gl.bindTexture(gl.TEXTURE_2D, tex);
                        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
                        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
                        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
                        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

                        // 初始化时不更新纹理，等待 useEffect 中的更新
                        gl.bindTexture(gl.TEXTURE_2D, null);

                        this.tex = tex;
                        texRef.current = tex;

                        // 创建 LUT 纹理
                        const lutTex = createLutTexture(gl, currentColorMapType);
                        if (!lutTex) return;

                        this.lutTex = lutTex;
                        lutTexRef.current = lutTex;

                        // 缓存uniform位置
                        this.uniformLocations = {
                            'u_projection_fallback_matrix': gl.getUniformLocation(program, 'u_projection_fallback_matrix'),
                            'u_projection_matrix': gl.getUniformLocation(program, 'u_projection_matrix'),
                            'u_projection_tile_mercator_coords': gl.getUniformLocation(program, 'u_projection_tile_mercator_coords'),
                            'u_projection_clipping_plane': gl.getUniformLocation(program, 'u_projection_clipping_plane'),
                            'u_projection_transition': gl.getUniformLocation(program, 'u_projection_transition'),
                            'u_tex': gl.getUniformLocation(program, 'u_tex'),
                            'u_lut': gl.getUniformLocation(program, 'u_lut')
                        };

                        // 创建并绑定顶点缓冲区
                        const vertexBuffer = gl.createBuffer();
                        if (!vertexBuffer) {
                            console.error('Failed to create vertex buffer');
                            return;
                        }

                        // 创建并绑定索引缓冲区
                        const indexBuffer = gl.createBuffer();
                        if (!indexBuffer) {
                            console.error('Failed to create index buffer');
                            return;
                        }

                        // Create vertex array object (WebGL2 feature)
                        const vao = gl.createVertexArray();
                        if (!vao) {
                            console.error('Failed to create VAO');
                            return;
                        }

                        gl.bindVertexArray(vao);

                        gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);

                        // 设置位置属性 (location = 0)
                        gl.enableVertexAttribArray(0);
                        gl.vertexAttribPointer(
                            0,          // attribute location
                            2,          // size (x, y)
                            gl.FLOAT,   // type
                            false,      // normalized
                            16,         // stride (4 floats * 4 bytes = 16 bytes per vertex)
                            0           // offset (位置在开始)
                        );
                        gl.vertexAttribDivisor(0, 0);

                        // 设置纹理坐标属性 (location = 1)
                        gl.enableVertexAttribArray(1);
                        gl.vertexAttribPointer(
                            1,          // attribute location
                            2,          // size (u, v)
                            gl.FLOAT,   // type
                            false,      // normalized
                            16,         // stride (4 floats * 4 bytes = 16 bytes per vertex)
                            8           // offset (纹理坐标在位置之后，2 floats * 4 bytes = 8 bytes)
                        );
                        gl.vertexAttribDivisor(1, 0);

                        gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);

                        // Unbind VAO
                        gl.bindVertexArray(null);

                        this.vao = vao;
                        this.vertexBuffer = vertexBuffer;
                        this.indexBuffer = indexBuffer;

                        setIsReady(true)
                    }

                    // 只在缩放级别变化时更新网格数据
                    const currentZoom = Math.floor(map.getZoom());
                    if (currentZoom !== this.lastZoom) {
                        console.log(`缩放级别变化: ${this.lastZoom} -> ${currentZoom}`);

                        // 智能计算最佳细分数量
                        const performanceLevel = detectPerformanceLevel();
                        const canvas = map.getCanvas();
                        const viewportSize = canvas ? {
                            width: canvas.width,
                            height: canvas.height
                        } : undefined;

                        // 获取细分建议信息
                        const recommendation = getSubdivisionRecommendation(currentZoom, performanceLevel);
                        console.log(`缩放级别: ${currentZoom}, 性能等级: ${performanceLevel}`);
                        console.log(`细分建议: ${recommendation.subdivisions} (${recommendation.description})`);
                        console.log(`三角形数量: ${recommendation.triangleCount}, 预计内存: ${recommendation.estimatedMemoryMB}MB`);

                        const meshData = RegionMeshPresets.china(currentZoom, 32);

                        if (gl instanceof WebGL2RenderingContext && this.vertexBuffer && this.indexBuffer) {
                            // 更新顶点缓冲区
                            gl.bindBuffer(gl.ARRAY_BUFFER, this.vertexBuffer);
                            gl.bufferData(gl.ARRAY_BUFFER, meshData.vertices, gl.STATIC_DRAW);
                            gl.bindBuffer(gl.ARRAY_BUFFER, null);

                            // 更新索引缓冲区
                            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.indexBuffer);
                            gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, meshData.indices, gl.STATIC_DRAW);
                            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);

                            this.meshData = meshData;
                            this.lastZoom = currentZoom;
                        }
                    }

                    // 移除这里的纹理更新，避免循环更新


                },

                onAdd: function (map: maplibregl.Map, gl: WebGL2RenderingContext) {
                    console.log('Custom layer added');
                    customLayerRef.current = this;
                },

                onRemove: function (map: maplibregl.Map, gl: WebGL2RenderingContext) {
                    // 清理WebGL资源
                    if (this.program) {
                        if (gl) {
                            // 禁用顶点属性
                            gl.disableVertexAttribArray(0); // 位置属性
                            gl.disableVertexAttribArray(1); // 纹理坐标属性

                            gl.deleteProgram(this.program);
                            if (this.vertexBuffer) gl.deleteBuffer(this.vertexBuffer);
                            if (this.indexBuffer) gl.deleteBuffer(this.indexBuffer);
                            if (this.vao) gl.deleteVertexArray(this.vao);
                            if (this.tex) gl.deleteTexture(this.tex);
                            if (this.lutTex) gl.deleteTexture(this.lutTex);
                        }
                    }
                    console.log('Custom layer resources cleaned up');
                },

                render(gl: WebGL2RenderingContext | WebGLRenderingContext, { defaultProjectionData }: CustomRenderMethodInput) {

                    if (!(gl instanceof WebGL2RenderingContext) || !this.program || !this.meshData || !this.vao) {
                        return;
                    }

                    // 保存当前状态
                    const currentProgram = gl.getParameter(gl.CURRENT_PROGRAM);
                    const currentVAO = gl.getParameter(gl.VERTEX_ARRAY_BINDING);
                    const blendEnabled = gl.isEnabled(gl.BLEND);
                    const currentBlendSrc = gl.getParameter(gl.BLEND_SRC_ALPHA);
                    const currentBlendDst = gl.getParameter(gl.BLEND_DST_ALPHA);

                    gl.useProgram(this.program);

                    // 使用缓存的uniform位置
                    const locations = this.uniformLocations!;

                    if (locations['u_projection_fallback_matrix']) {
                        gl.uniformMatrix4fv(
                            locations['u_projection_fallback_matrix'],
                            false,
                            defaultProjectionData.fallbackMatrix
                        );
                    }

                    if (locations['u_projection_matrix']) {
                        gl.uniformMatrix4fv(
                            locations['u_projection_matrix'],
                            false,
                            defaultProjectionData.mainMatrix
                        );
                    }

                    if (locations['u_projection_tile_mercator_coords']) {
                        gl.uniform4f(
                            locations['u_projection_tile_mercator_coords'],
                            ...defaultProjectionData.tileMercatorCoords
                        );
                    }

                    if (locations['u_projection_clipping_plane']) {
                        gl.uniform4f(
                            locations['u_projection_clipping_plane'],
                            ...defaultProjectionData.clippingPlane
                        );
                    }

                    if (locations['u_projection_transition']) {
                        gl.uniform1f(
                            locations['u_projection_transition'],
                            defaultProjectionData.projectionTransition
                        );
                    }

                    // 绑定纹理
                    if (this.tex && locations['u_tex']) {
                        gl.activeTexture(gl.TEXTURE0);
                        gl.bindTexture(gl.TEXTURE_2D, this.tex);
                        gl.uniform1i(locations['u_tex'], 0);
                    }

                    if (this.lutTex && locations['u_lut']) {
                        gl.activeTexture(gl.TEXTURE1);
                        gl.bindTexture(gl.TEXTURE_2D, this.lutTex);
                        gl.uniform1i(locations['u_lut'], 1);
                    }

                    gl.bindVertexArray(this.vao);
                    gl.enable(gl.BLEND);
                    gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);

                    // 使用索引绘制三角形
                    const indexType = this.meshData.uses32bitIndices ? gl.UNSIGNED_INT : gl.UNSIGNED_SHORT;
                    const indexCount = this.meshData.indices.length;
                    gl.drawElements(gl.TRIANGLES, indexCount, indexType, 0);

                    // 恢复状态
                    gl.bindVertexArray(currentVAO);
                    gl.useProgram(currentProgram);
                    if (!blendEnabled) gl.disable(gl.BLEND);
                    if (blendEnabled) gl.blendFunc(currentBlendSrc, currentBlendDst);
                }
            };

            map.addLayer(customGlLayer);
        })


        setMap(map, [])

        // 清理函数：当组件卸载或重新初始化时清理资源
        return () => {
            console.log('Cleaning up map resources...');

            // 清理自定义图层引用
            customLayerRef.current = null;

            // 清理 WebGL 引用
            glRef.current = null;
            texRef.current = null;
            lutTexRef.current = null;

            // 重置状态
            setIsReady(false);

            // 移除地图实例
            if (map) {
                map.remove();
            }
        }

    }, [mapContainer])

    useEffect(() => {
        if (imgBitmap && texRef.current) {
            const gl = glRef.current
            if (!gl) return;

            console.log('Updating texture with imgBitmap:', imgBitmap);

            gl.bindTexture(gl.TEXTURE_2D, texRef.current)

            // 针对灰度图优化：使用单通道RED格式，减少内存使用和提高性能
            // 虽然ImageBitmap仍是RGBA格式，但WebGL会自动将灰度值映射到RED通道
            gl.texImage2D(
                gl.TEXTURE_2D,
                0,
                gl.RGBA,          // 内部格式：使用RGBA，兼容性更好
                gl.RGBA,          // 数据格式：ImageBitmap总是RGBA
                gl.UNSIGNED_BYTE,
                imgBitmap
            )

            // 设置纹理参数（如果还没有设置）
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

            gl.bindTexture(gl.TEXTURE_2D, null);

            // Redraw the map
            mapRef.current?.triggerRepaint()

        }

    }, [imgBitmap, isReady])

    // 监听色标类型变化，更新LUT纹理
    useEffect(() => {
        if (currentColorMapType !== colorMapType) {
            setCurrentColorMapType(colorMapType);
        }
    }, [colorMapType, currentColorMapType])

    // 当色标类型改变时，重新创建LUT纹理
    useEffect(() => {
        if (isReady && lutTexRef.current && glRef.current) {
            const gl = glRef.current;
            const newLutTex = createLutTexture(gl, currentColorMapType);
            if (newLutTex) {
                // 删除旧的纹理
                gl.deleteTexture(lutTexRef.current);
                lutTexRef.current = newLutTex;

                // 通知自定义图层更新LUT纹理
                if (customLayerRef.current) {
                    customLayerRef.current.lutTex = newLutTex;
                }
            }
        }
    }, [currentColorMapType, isReady])

    return (
        <div className="relative w-full h-full" style={{ minHeight: '400px' }}>
            <div
                ref={mapContainer}
                className="w-full h-full"
            />

            {/* Colorbar 在右下角 */}
            <div className="absolute bottom-4 right-4 bg-white/90 backdrop-blur-sm rounded-lg p-3 shadow-lg border">
                <div className="text-xs text-gray-600 mb-2 font-medium">色标</div>
                <Colorbar
                    colorMapType={currentColorMapType}
                    width={180}
                    height={16}
                    minValue={0}
                    maxValue={75}
                    unit="dBZ"
                />
            </div>
        </div>
    )
}


interface CustomGlLayer extends CustomLayerInterface {
    program?: WebGLProgram;
    aPos?: number;
    buffer?: WebGLBuffer | null;
    vao?: WebGLVertexArrayObject | null;
    meshData?: { vertices: Float32Array; indices: Uint16Array | Uint32Array; uses32bitIndices: boolean; vertexCount: number; triangleCount: number; };
    vertexBuffer?: WebGLBuffer | null;
    indexBuffer?: WebGLBuffer | null;
    lastZoom?: number; // 缓存的缩放级别
    uniformLocations?: Record<string, WebGLUniformLocation | null>; // 缓存uniform位置

    tex?: WebGLTexture | null;
    lutTex?: WebGLTexture | null;
}



function createLutTexture(gl: WebGL2RenderingContext, colorMapType: ColorMapType = 'radar') {
    // 使用统一的色标创建函数
    const lut = createColorMap(colorMapType);

    const tex = gl.createTexture()
    if (!tex) {
        console.error('Failed to create texture');
        return;
    }

    gl.bindTexture(gl.TEXTURE_2D, tex)
    gl.texImage2D(
        gl.TEXTURE_2D,
        0,
        gl.RGBA,
        256,
        1,
        0,
        gl.RGBA,
        gl.UNSIGNED_BYTE,
        lut
    )

    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

    gl.bindTexture(gl.TEXTURE_2D, null);

    return tex;
}