// Apply operations to text content (mirrors fs_write semantics)
import type { Operation } from './types.js';
export function applyOperation(content: string, operation: Operation): string {
switch (operation.type) {
case 'create': {
return operation.file_text;
}
case 'str_replace': {
const { old_str, new_str } = operation;
if (!content.includes(old_str)) {
throw new Error(`str_replace failed: old_str not found in content`);
}
// Check uniqueness - fail if old_str appears more than once
const firstIndex = content.indexOf(old_str);
const secondIndex = content.indexOf(old_str, firstIndex + 1);
if (secondIndex !== -1) {
throw new Error(`str_replace failed: old_str is not unique in file. Include more context to make it unique.`);
}
return content.replace(old_str, new_str);
}
case 'insert': {
// insert_line: insert AFTER this line (1-based, like fs_write)
const lines = content.split('\n');
const lineNum = operation.insert_line;
if (lineNum < 0 || lineNum > lines.length) {
throw new Error(`insert failed: line ${lineNum} out of range (0-${lines.length})`);
}
lines.splice(lineNum, 0, operation.new_str);
return lines.join('\n');
}
case 'append': {
// Add newline if file doesn't end with one (like fs_write)
const needsNewline = content.length > 0 && !content.endsWith('\n');
return content + (needsNewline ? '\n' : '') + operation.new_str;
}
default:
throw new Error(`Unknown operation type: ${(operation as any).type}`);
}
}
