import { type ReadableStream } from 'node:stream/web'
import knex from './knex.ts'

import split, { type Decoder } from './split.ts'
import {
  parseDim,
  parseIB,
  parseKonto,
  parseObjekt,
  parseRAR,
  parseSRU,
  parseTrans,
  parseUB,
  parseVer,
} from './parse_line.ts'

const defaultDecoder = {
  decode(chunk: Uint8Array) {
    return Array.from(chunk, (uint) => {
      switch (uint) {
        case 132:
          return 'ä'
        case 134:
          return 'å'
        case 148:
          return 'ö'
        case 142:
          return 'Ä'
        case 143:
          return 'Å'
        case 153:
          return 'Ö'
        default:
          return String.fromCharCode(uint)
      }
    }).join('')
  },
}

export default async function parseStream(stream: ReadableStream, decoder: Decoder = defaultDecoder) {
  const journals = new Map()

  let currentEntryId: number
  let currentInvoiceId: number
  let currentYear = null
  const details: Record<string, string> = {}

  const trx = await knex.transaction()

  async function getJournalId(identifier: string) {
    if (journals.has(identifier)) {
      return journals.get(identifier)
    }

    let journal = await trx('journal').first('*').where('identifier', identifier)

    if (!journal) {
      journal = (await trx('journal').insert({ identifier }).returning('*'))[0]
    }

    journals.set(identifier, journal.id)

    return journal.id
  }

  for await (let line of stream.pipeThrough(split(null, { decoder }))) {
    line = line.trim()

    if (line[0] !== '#') {
      continue
    }

    const splitLine = line.split(/\s+/)
    const lineType = splitLine[0]

    switch (lineType) {
      case '#DIM': {
        const { number, name } = parseDim(line)

        const existingDimension = await trx('dimension').first('*').where('number', number)

        if (!existingDimension) {
          await trx('dimension').insert({ number, name })
        } else if (existingDimension.name !== name) {
          await trx('dimension').update({ name }).where('number', number)
        }

        break
      }
      case '#IB': {
        const { yearNumber, accountNumber, balance, quantity } = parseIB(line)

        if (yearNumber !== 0) continue

        const existingAccountBalance = await trx('accountBalance')
          .first('*')
          .where({ financialYearId: currentYear.id, accountNumber })

        if (!existingAccountBalance) {
          await trx('accountBalance').insert({
            financialYearId: currentYear.id,
            accountNumber,
            in: balance,
            inQuantity: quantity,
          })
        } else {
          await trx('accountBalance')
            .update({
              in: balance,
              inQuantity: quantity,
            })
            .where({
              financialYearId: currentYear.id,
              accountNumber,
            })
        }

        break
      }
      case '#KONTO': {
        const { number, description } = parseKonto(line)

        const existingAccount = await trx('account')
          .first('*')
          .where('number', number)
          .orderBy('financialYearId', 'desc')

        if (!existingAccount) {
          await trx('account').insert({
            financialYearId: currentYear!.id,
            number,
            description,
          })
        } else if (existingAccount.description !== description) {
          await trx('account').update({ description }).where('id', existingAccount.id)
        }

        break
      }
      case '#OBJEKT': {
        const { dimensionNumber, number, name } = parseObjekt(line)

        const dimension = await trx('dimension').first('*').where('number', dimensionNumber)

        if (!dimension) throw new Error(`Dimension "${dimensionNumber}" does not exist`)

        const existingObject = await trx('object').first('*').where({ dimensionId: dimension.id, number })

        if (!existingObject) {
          await trx('object').insert({ dimensionId: dimension.id, number, name })
        } else if (existingObject.name !== name) {
          await trx('object').update({ name }).where({ dimensionId: dimension.id, number })
        }

        break
      }
      case '#RAR': {
        const { yearNumber, startDate, endDate } = parseRAR(line)

        if (yearNumber !== 0) continue

        currentYear = (
          await trx('financial_year')
            .insert({ year: startDate.slice(0, 4), startDate, endDate })
            .returning('*')
        )[0]

        break
      }
      case '#SRU': {
        const { number, sru } = parseSRU(line)

        const existingAccount = await trx('account')
          .first('*')
          .where('number', number)
          .orderBy('financialYearId', 'desc')

        if (existingAccount) {
          if (existingAccount.sru !== sru) {
            await trx('account').update({ sru: sru }).where('id', existingAccount.id)
          }
        } else {
          await trx('account').insert({
            financialYearId: currentYear!.id,
            number,
            description: existingAccount.description,
            sru,
          })
        }

        break
      }
      case '#TRANS': {
        const { objectList, ...transaction } = parseTrans(line)
        // Faktura 6364710056 172-2 - SBAB Bank AB
        // Faktura 2312 172-6 - Bredablick Frvaltning AB
        const rFisken = /Faktura.*172-(\d*)\s+-\s+(.+)/

        const result = transaction.description?.match(rFisken)

        let invoiceId: number

        if (result) {
          const [, fiskenNumber, supplierName] = result
          // invoiceId = (await trx('invoice').first('id').where({ fiskenNumber})).id
          invoiceId = (await trx('invoice').first('id').where({ fiskenNumber }))?.id

          if (!invoiceId) {
            let supplierId = (await trx('supplier').first('id').where('name', supplierName))?.id

            if (!supplierId) {
              supplierId = (await trx('supplier').insert({ name: supplierName, supplierTypeId: 1 }).returning('id'))[0]
                ?.id
            }

            invoiceId = (
              await trx('invoice').insert({ financialYearId: currentYear.id, fiskenNumber, supplierId }).returning('id')
            )[0]?.id
          }
        }

        if (invoiceId && currentInvoiceId) {
          throw new Error('invoiceId and currentInvoiceId')
        }

        const transactionId = (
          await trx('transaction')
            .insert({
              entryId: currentEntryId,
              ...transaction,
              invoiceId: invoiceId || currentInvoiceId,
            })
            .returning('id')
        )[0].id

        if (objectList) {
          for (const [dimensionNumber, objectNumber] of objectList) {
            const objectId = (
              await trx('object')
                .first('object.id')
                .innerJoin('dimension', 'object.dimension_id', 'dimension.id')
                .where({
                  'object.number': objectNumber,
                  'dimension.number': dimensionNumber,
                })
            )?.id

            if (!objectId) {
              throw new Error(`Object {${dimensionNumber} ${objectNumber}} does not exist!`)
            }

            await trx('transactionsToObjects').insert({
              transactionId,
              objectId,
            })
          }
        }

        break
      }
      case '#UB': {
        const { yearNumber, accountNumber, balance, quantity } = parseUB(line)

        if (yearNumber !== 0) continue

        const existingAccountBalance = await trx('accountBalance')
          .first('*')
          .where({ financialYearId: currentYear.id, accountNumber })

        if (!existingAccountBalance) {
          await trx('accountBalance').insert({
            financialYearId: currentYear.id,
            accountNumber,
            out: balance,
            outQuantity: quantity,
          })
        } else {
          await trx('accountBalance')
            .update({
              out: balance,
              outQuantity: quantity,
            })
            .where({
              financialYearId: currentYear.id,
              accountNumber,
            })
        }

        break
      }
      case '#VER': {
        const { journal, ...rest } = parseVer(line)

        let journalId = await getJournalId(journal)

        // Fisken - Fakturajournal 1248
        // Fisken - Utbetalningsjournal 1056

        // Levfakt EURO FINANS AB (5) / Levfakt Per Holmberg (6)
        // Levbet EURO FINANS AB (5) / Levbet Per Holmberg (6)
        const rPhm = /^Lev(?:fakt|bet)\s+[^(]*\((\d+)\)$/

        const result = rest.description.match(rPhm)

        if (result) {
          currentInvoiceId = (
            await trx('invoice')
              .select('invoice.*', 'supplier.name')
              .innerJoin('supplier', 'invoice.supplierId', 'supplier.id')
              .where('phmNumber', result[1])
          )[0]?.id
        } else {
          currentInvoiceId = null
        }

        currentEntryId = (
          await trx('entry')
            .insert({
              journalId,
              financialYearId: currentYear!.id,
              ...rest,
            })
            .returning('id')
        )[0].id

        break
      }
      default:
        details[lineType] = splitLine.slice(1).join(' ')
    }
  }

  await trx.commit()

  console.dir(details)

  console.info(`DONE!: ${currentYear.startDate} - ${currentYear.endDate}`)
}