import { readFile, writeFile } from 'fs/promises'
import { join } from 'path'

import {
    generateReaderCodeForTlEntries,
    generateTypescriptDefinitionsForTlSchema,
    generateWriterCodeForTlEntries,
    parseFullTlSchema,
    TlEntry,
    TlErrors,
    TlFullSchema,
} from '@mtcute/tl-utils'

import { API_SCHEMA_JSON_FILE, ERRORS_JSON_FILE, ESM_PRELUDE, MTP_SCHEMA_JSON_FILE } from './constants'
import { TlPackedSchema, unpackTlSchema } from './schema'

const OUT_TYPINGS_FILE = join(__dirname, '../index.d.ts')
const OUT_TYPINGS_JS_FILE = join(__dirname, '../index.js')
const OUT_READERS_FILE = join(__dirname, '../binary/reader.js')
const OUT_WRITERS_FILE = join(__dirname, '../binary/writer.js')

async function generateTypings(apiSchema: TlFullSchema, apiLayer: number, mtpSchema: TlFullSchema, errors: TlErrors) {
    console.log('Generating typings...')
    const [apiTs, apiJs] = generateTypescriptDefinitionsForTlSchema(apiSchema, apiLayer, undefined, errors)
    const [mtpTs, mtpJs] = generateTypescriptDefinitionsForTlSchema(mtpSchema, 0, 'mtp')

    await writeFile(OUT_TYPINGS_FILE, apiTs + '\n\n' + mtpTs.replace("import _Long from 'long';", ''))
    await writeFile(OUT_TYPINGS_JS_FILE, ESM_PRELUDE + apiJs + '\n\n' + mtpJs)
}

async function generateReaders(apiSchema: TlFullSchema, mtpSchema: TlFullSchema) {
    console.log('Generating readers...')

    let code = generateReaderCodeForTlEntries(apiSchema.entries, {
        variableName: 'm',
        includeMethods: false,
        includeMethodResults: true,
    })

    const mtpCode = generateReaderCodeForTlEntries(mtpSchema.entries, {
        variableName: 'm',
    })
    code = code.substring(0, code.length - 1) + mtpCode.substring(8)
    code += '\nexports.default = m;'

    await writeFile(OUT_READERS_FILE, ESM_PRELUDE + code)
}

async function generateWriters(apiSchema: TlFullSchema, mtpSchema: TlFullSchema) {
    console.log('Generating writers...')

    let code = generateWriterCodeForTlEntries([...apiSchema.entries, ...mtpSchema.entries], {
        variableName: 'm',
        includeStaticSizes: true,
    })

    code += '\nexports.default = m;'

    await writeFile(OUT_WRITERS_FILE, ESM_PRELUDE + code)
}

async function main() {
    const errors = JSON.parse(await readFile(ERRORS_JSON_FILE, 'utf8')) as TlErrors

    const [apiSchema, apiLayer] = unpackTlSchema(
        JSON.parse(await readFile(API_SCHEMA_JSON_FILE, 'utf8')) as TlPackedSchema,
    )
    const mtpSchema = parseFullTlSchema(JSON.parse(await readFile(MTP_SCHEMA_JSON_FILE, 'utf8')) as TlEntry[])

    await generateTypings(apiSchema, apiLayer, mtpSchema, errors)
    await generateReaders(apiSchema, mtpSchema)
    await generateWriters(apiSchema, mtpSchema)

    console.log('Done!')
}

main().catch(console.error)