import assert from 'node:assert/strict'
import test from 'node:test'

import { compareSnapshots, parseMetadataRows } from './database-schema-diff.mjs'

test('metadata transport preserves Unicode, escaped control characters and expression defaults', () => {
  const rows = [{ schema: 'sample', table: 'orders', defaultValue: '国内\r\n海外\t"quote"\\path', generation: "concat('x', '\\n')" }, { defaultValue: null }]
  const output = rows.map(row => Buffer.from(JSON.stringify(row), 'utf8').toString('hex')).join('\r\n') + '\r\n'
  assert.deepEqual(parseMetadataRows(output), rows)
  assert.deepEqual(parseMetadataRows(''), [])
})

test('metadata transport rejects invalid or truncated records', () => {
  assert.throws(() => parseMetadataRows('abc'), /HEX JSON/)
  assert.throws(() => parseMetadataRows('not-json'), /HEX JSON/)
  assert.throws(() => parseMetadataRows(Buffer.from('{"schema":').toString('hex')), SyntaxError)
})

test('database schema diff ignores column order but catches contract changes', () => {
  const left = {
    schemas: [{ schema: 'sample' }],
    tables: [{ schema: 'sample', table: 'orders', type: 'BASE TABLE', engine: 'InnoDB', collation: 'utf8mb4_0900_ai_ci' }],
    columns: [
      { schema: 'sample', table: 'orders', column: 'id', ordinal: 1, type: 'bigint', nullable: 'NO', defaultValue: null, extra: '', charset: null, collation: null, generation: '' },
    ],
  }
  const reordered = structuredClone(left)
  reordered.columns[0].ordinal = 9
  assert.deepEqual(compareSnapshots(left, reordered).columns, { leftOnly: [], rightOnly: [], changed: [] })

  reordered.columns[0].nullable = 'YES'
  const changed = compareSnapshots(left, reordered).columns.changed
  assert.equal(changed.length, 1)
  assert.equal(changed[0].key, 'sample.orders.id')
})

test('database schema diff reports objects present on only one side', () => {
  const left = { schemas: [{ schema: 'sample' }], tables: [], columns: [] }
  const right = {
    schemas: [{ schema: 'sample' }],
    tables: [{ schema: 'sample', table: 'orders', type: 'BASE TABLE', engine: 'InnoDB', collation: 'utf8mb4_0900_ai_ci' }],
    columns: [{ schema: 'sample', table: 'orders', column: 'id', type: 'bigint', nullable: 'NO', defaultValue: null, extra: '', charset: null, collation: null, generation: '' }],
  }
  const diff = compareSnapshots(left, right)
  assert.deepEqual(diff.tables.rightOnly, ['sample.orders'])
  assert.deepEqual(diff.columns.rightOnly, ['sample.orders.id'])
})