import type { FunctionAssignmentNode } from 'mathjs';
import type { Result } from './interface.js';
import { migrateAtomic } from './node.js';
import { type State, FunctionState } from './state.js';
import { migrateSymbolName } from './utils.js';

/** 转换函数定义语句 */
export function migrateFunctionAssignment(state: State, node: FunctionAssignmentNode): Result {
    state.loose();
    const { name, params, expr } = node;
    const fState = new FunctionState(state, params);
    let body = migrateAtomic(fState, expr);
    if (!(body.code.startsWith('{') && body.code.endsWith('}'))) {
        body = { ...body, code: `{ ${body.code} }` };
    }
    if (state.locals.has(name)) {
        state.err(`重复定义函数: '${name}'`);
    }
    state.locals.set(name, {
        type: 'function',
        code: body.code,
    });
    return {
        type: 'function',
        code: `fn ${migrateSymbolName(name, true)}(${params.join(', ')}) ${body.code}`,
    };
}