import { describe, it, expect } from 'vitest'

import { serializeCsv } from '@app/services/export/csv.serializer'

import { buildManifest } from '@app/services/export/manifest.builder'

import { profileTable } from '@app/services/export/table.descriptors'

import { CsvTable } from '@app/services/export/types'

describe('serializeCsv', () => {

  it('keeps the header row and a BOM when the table has no rows', () => {

    const file = serializeCsv(profileTable, [])

    const text = file.content.toString('utf8')

    expect(text.startsWith('\ufeff')).toBe(true)

    expect(file.rows).toBe(0)

    const lines = text.slice(1).split('\r\n').filter(Boolean)

    expect(lines).toHaveLength(1)

    expect(lines[0]).toContain('Email')

  })

  it('round-trips commas, double quotes, and newlines through escaped fields', () => {

    const table: CsvTable<{ text: string }> = {

      filename: 'notes.csv',

      columns: [{ header: 'Texto', value: (row) => row.text }],

    }

    const values = ['a,b', 'he said "hi"', 'line one\nline two']

    const file = serializeCsv(

      table,

      values.map((text) => ({ text })),

    )

    const body = file.content.toString('utf8').slice(1)

    // RFC 4180: every string field is quoted and any inner quote doubled, so

    // reading the quoted fields back and undoubling the quotes recovers the

    // original values byte-for-byte.

    const fields = [...body.matchAll(/"((?:[^"]|"")*)"/g)].map((match) =>

      match[1].replaceAll('""', '"'),

    )

    expect(fields).toEqual(['Texto', ...values])

    expect(file.rows).toBe(3)

  })

})

describe('buildManifest', () => {

  it('states the generation time and lists each file with its row count', () => {

    const manifest = buildManifest(

      [{ filename: 'profile.csv', content: Buffer.from(''), rows: 0 }],

      new Date('2026-10-04T12:00:00.000Z'),

    )

    const text = manifest.content.toString('utf8')

    expect(manifest.filename).toBe('leia-me.md')

    expect(text).toContain('2026-10-04T12:00:00.000Z')

    expect(text).toContain('`profile.csv` — 0 registros')

    expect(text).toContain('_id')

  })

  it('lists every file and singularizes a count of one', () => {

    const manifest = buildManifest(

      [

        { filename: 'moods.csv', content: Buffer.from(''), rows: 1 },

        { filename: 'triggers.csv', content: Buffer.from(''), rows: 3 },

      ],

      new Date('2026-10-04T12:00:00.000Z'),

    )

    const text = manifest.content.toString('utf8')

    expect(text).toContain('`moods.csv` — 1 registro')

    expect(text).toContain('`triggers.csv` — 3 registros')

  })

})