import { describe, expect, it } from 'vitest';
import { pressKey, evaluateExpression } from '../src/components/numpadExpression';
import { parsePostingsToLegs } from '../src/domain/postingLegs';
import { buildPostings } from '../src/domain/transactionBuilder';

describe('pressKey 表达式编辑', () => {
  it('数字键追加', () => {
    expect(pressKey('', '5')).toBe('5');
    expect(pressKey('5', '3')).toBe('53');
  });

  it('前导零被替换', () => {
    expect(pressKey('0', '5')).toBe('5');
  });

  it('小数点：空段补 0，同段不重复', () => {
    expect(pressKey('', '.')).toBe('0.');
    expect(pressKey('5', '.')).toBe('5.');
    expect(pressKey('5.5', '.')).toBe('5.5');
  });

  it('小数最多两位', () => {
    expect(pressKey('5.55', '5')).toBe('5.55');
    expect(pressKey('5.5', '5')).toBe('5.55');
  });

  it('整数位最多 9 位', () => {
    expect(pressKey('123456789', '0')).toBe('123456789');
    expect(pressKey('12345678', '9')).toBe('123456789');
  });

  it('9 位整数后仍可输入小数', () => {
    expect(pressKey('123456789.', '5')).toBe('123456789.5');
    expect(pressKey('123456789.5', '5')).toBe('123456789.55');
  });

  it('运算符：数字后可加，连续运算符替换，空表达式不可加', () => {
    expect(pressKey('5', '+')).toBe('5+');
    expect(pressKey('5+', '-')).toBe('5-');
    expect(pressKey('', '+')).toBe('');
    expect(pressKey('', '-')).toBe('');
  });

  it('运算符后开启新数字段（小数规则独立）', () => {
    expect(pressKey('5.5+', '.')).toBe('5.5+0.');
    expect(pressKey('5.55+3', '.')).toBe('5.55+3.');
  });

  it('backspace 删除末字符', () => {
    expect(pressKey('5.5', 'backspace')).toBe('5.');
    expect(pressKey('5', 'backspace')).toBe('');
    expect(pressKey('', 'backspace')).toBe('');
  });
});

describe('evaluateExpression 求值', () => {
  it('单值', () => {
    expect(evaluateExpression('35')).toBe('35');
  });

  it('加减混合（字符串十进制，无浮点误差）', () => {
    expect(evaluateExpression('20+15')).toBe('35');
    expect(evaluateExpression('20+15-5.5')).toBe('29.5');
    expect(evaluateExpression('0.1+0.2')).toBe('0.3');
  });

  it('尾随运算符被忽略', () => {
    expect(evaluateExpression('20+')).toBe('20');
    expect(evaluateExpression('20+15-')).toBe('35');
  });

  it('空表达式返回空串', () => {
    expect(evaluateExpression('')).toBe('');
  });

  it('段尾小数点不崩溃（键盘可达状态）', () => {
    expect(evaluateExpression('5.')).toBe('5');
    expect(evaluateExpression('5.+3')).toBe('8');
  });

  it('净额可为负', () => {
    expect(evaluateExpression('5-10')).toBe('-5');
  });
});

describe('parsePostingsToLegs 双腿解析', () => {
  it('与 buildPostings 往返一致：支出', () => {
    const legs = parsePostingsToLegs(buildPostings('expense', 'Assets:招行', 'Expenses:餐饮', '35', 'CNY'));
    expect(legs).toEqual({
      direction: 'expense',
      sourceAccount: 'Assets:招行',
      targetAccount: 'Expenses:餐饮',
      amount: '35',
      currency: 'CNY',
    });
  });

  it('与 buildPostings 往返一致：收入', () => {
    const legs = parsePostingsToLegs(buildPostings('income', 'Assets:招行', 'Income:工资', '12000', 'CNY'));
    expect(legs).toEqual({
      direction: 'income',
      sourceAccount: 'Assets:招行',
      targetAccount: 'Income:工资',
      amount: '12000',
      currency: 'CNY',
    });
  });

  it('与 buildPostings 往返一致：转账', () => {
    const legs = parsePostingsToLegs(buildPostings('transfer', 'Assets:招行', 'Liabilities:花呗', '2000', 'CNY'));
    expect(legs).toEqual({
      direction: 'transfer',
      sourceAccount: 'Assets:招行',
      targetAccount: 'Liabilities:花呗',
      amount: '2000',
      currency: 'CNY',
    });
  });

  it('金额取绝对值（去掉负号）', () => {
    const legs = parsePostingsToLegs([
      { account: 'Assets:招行', amount: '-35', currency: 'CNY' },
      { account: 'Expenses:餐饮', amount: '35', currency: 'CNY' },
    ]);
    expect(legs?.amount).toBe('35');
  });

  it('无法识别时返回 null', () => {
    expect(parsePostingsToLegs([])).toBeNull();
    expect(parsePostingsToLegs([{ account: 'Assets:招行', amount: '35', currency: 'CNY' }])).toBeNull();
  });

  it('拆分交易（3 条分录）返回 null，走高级模式', () => {
    expect(
      parsePostingsToLegs([
        { account: 'Assets:招行', amount: '-35', currency: 'CNY' },
        { account: 'Expenses:餐饮', amount: '30', currency: 'CNY' },
        { account: 'Expenses:小费', amount: '5', currency: 'CNY' },
      ])
    ).toBeNull();
  });

  it('识别腿缺金额时回退用对侧资金腿', () => {
    const legs = parsePostingsToLegs([
      { account: 'Assets:招行', amount: '-35', currency: 'CNY' },
      { account: 'Expenses:餐饮' },
    ]);
    expect(legs?.amount).toBe('35');
  });

  it('转账正腿在前时按负号判定转出方', () => {
    const legs = parsePostingsToLegs([
      { account: 'Assets:A', amount: '100', currency: 'CNY' },
      { account: 'Assets:B', amount: '-100', currency: 'CNY' },
    ]);
    expect(legs?.sourceAccount).toBe('Assets:B');
    expect(legs?.targetAccount).toBe('Assets:A');
  });
});