/**
 * 修补 Cesium.js：在 uniform 类型 switch-case 中添加 SAMPLER_3D (35679) 支持。
 * 
 * SuperMap 定制的 Cesium.js 在 PostProcessStage 的 uniform setter 创建逻辑中
 * 缺少对 SAMPLER_3D 分支的处理，导致 sampler3D 类型的 uniform 绑定失败。
 *
 * 本脚本通过分析 obfuscated 代码中的 SAMPLER constants 定义，找到对应的
 * WebGL 常量值，并在 switch-case 中插入缺失的 SAMPLER_3D 分支。
 */

const fs = require('fs');
const path = require('path');

const filePath = path.join(__dirname, 'public/Cesium/Cesium.js');
let content = fs.readFileSync(filePath, 'utf8');

// Step 1: Find SAMPLER_3D constant definition
// Looking for: 'SAMPLER_3D':0x8b5f
const sampler3DConstIdx = content.indexOf("'SAMPLER_3D'");
if (sampler3DConstIdx < 0) {
    console.error('SAMPLER_3D constant not found in Cesium.js');
    process.exit(1);
}
console.log('SAMPLER_3D constant found at byte', sampler3DConstIdx);

// Step 2: Find SAMPLER_2D constant definition to find its numeric value
const sampler2DConstIdx = content.indexOf("'SAMPLER_2D'");
if (sampler2DConstIdx < 0) {
    console.error('SAMPLER_2D constant not found');
    process.exit(1);
}
console.log('SAMPLER_2D constant found at byte', sampler2DConstIdx);

// Step 3: Find the switch-case that handles uniform types
// Looking for the pattern: case ... SAMPLER_2D ... case ... SAMPLER_CUBE
// These are used in the uniform setter creation function

// Search for SAMPLER_CUBE in the context of a switch case
const switchPattern = /case\s+[^;]*?SAMPLER_2D[^;]*?case\s+[^;]*?SAMPLER_CUBE/g;
let match;
let found = false;

while ((match = switchPattern.exec(content)) !== null) {
    const fullMatch = match[0];
    console.log('\nFound SAMPLER_2D..SAMPLER_CUBE sequence at byte', match.index);
    console.log('Match:', fullMatch.substring(0, 200));
    
    // Check if SAMPLER_3D is already present between them
    if (fullMatch.includes('SAMPLER_3D')) {
        console.log('SAMPLER_3D already present - no patch needed!');
        found = true;
        continue;
    }
    
    // Find the pattern between SAMPLER_2D and SAMPLER_CUBE
    const s2Idx = fullMatch.indexOf('SAMPLER_2D');
    const scIdx = fullMatch.indexOf('SAMPLER_CUBE');
    const between = fullMatch.substring(s2Idx + 'SAMPLER_2D'.length, scIdx);
    
    console.log('Between SAMPLER_2D and SAMPLER_CUBE:', between.substring(0, 100));
    
    // Get the property access pattern: e.g., `_0x2cbe(0x...)` or `this.SAMPLER_2D`
    // We need to find how SAMPLER_2D's value is obtained
    const s2Access = fullMatch.substring(0, s2Idx).trim();
    const s2AccessClean = s2Access.replace(/^case\s+/, '').trim();
    console.log('SAMPLER_2D access pattern:', s2AccessClean.substring(0, 80));
    
    // The SAMPLER_2D access is via a property on an object
    // The SAMPLER_3D should use the SAME object but with SAMPLER_3D
    // e.g. if SAMPLER_2D is accessed as `_0x4b6e38.SAMPLER_2D`
    // then SAMPLER_3D should be `_0x4b6e38.SAMPLER_3D`
    
    const objMatch = s2AccessClean.match(/^([\w.]+)\.SAMPLER_2D$/);
    if (!objMatch) {
        console.log('Cannot parse access pattern, trying alternative...');
        // Could also be an array access like _0x...['SAMPLER_2D']
        continue;
    }
    
    const obj = objMatch[1];
    const sampler3DAccess = obj + ".SAMPLER_3D";
    const insertStr = "case " + sampler3DAccess + ":";
    
    console.log('Will insert:', insertStr);
    
    // Insert SAMPLER_3D case after SAMPLER_2D case
    const insertPos = match.index + s2Idx + 'SAMPLER_2D'.length + between.length;
    const insertion = "case " + sampler3DAccess + ":";
    
    content = content.substring(0, insertPos) + insertion + content.substring(insertPos);
    console.log('Inserted at byte', insertPos);
    
    found = true;
    break;
}

if (!found) {
    console.log('\nCould not find the switch-case pattern. Trying alternative approach...');
    
    // Alternative: Search for "SAMPLER_2D:SAMPLER_CUBE" or similar sequences
    // The obfuscated code might have these constant strings next to each other
    const altPattern = /SAMPLER_2D['"`:;,.\]]+SAMPLER_CUBE/g;
    while ((match = altPattern.exec(content)) !== null) {
        console.log('Alt pattern found at byte', match.index, ':', match[0].substring(0, 100));
    }
}

// Save the patched file
fs.writeFileSync(filePath, content, 'utf8');
console.log('\nPatch complete');