const { crc32 } = require('crc')
const struct = require('python-struct')
const { snakeToCamelCase } = require('../../utils')

// https://github.com/telegramdesktop/tdesktop/blob/4bf66cb6e93f3965b40084771b595e93d0b11bcd/Telegram/SourceFiles/codegen/scheme/codegen_scheme.py#L57-L62
const WHITELISTED_MISMATCHING_IDS = {
    // 0 represents any layer
    0: new Set([
        'channel', // Since layer 77, there seems to be no going back...
        'ipPortSecret',
        'accessPointRule',
        'help.configSimple',
    ]),
}

/**
 * Initializes a new TLObject, given its properties.
 *
 * :param fullname: The fullname of the TL object (namespace.name)
 *                  The namespace can be omitted.
 * :param object_id: The hexadecimal string representing the object ID
 * :param args: The arguments, if any, of the TL object
 * :param result: The result type of the TL object
 * :param is_function: Is the object a function or a type?
 * :param usability: The usability for this method.
 * :param friendly: A tuple (namespace, friendly method name) if known.
 * :param layer: The layer this TLObject belongs to.
 */
class TLObject {
    constructor(fullname, objectId, args, result, isFunction, usability, friendly, layer) {
        // The name can or not have a namespace
        this.fullname = fullname

        if (fullname.includes('.')) {
            [this.namespace, this.name] = fullname.split(/\.(.+)/)
            // console.log(fullname.split(/\.(.+)/));
            // const [namespace, ...name] = fullname.split('.');
            // this.namespace = namespace;
            // this.name = name.join('.');
        } else {
            this.namespace = null
            this.name = fullname
        }

        this.args = args
        this.result = result
        this.isFunction = isFunction
        this.usability = usability
        this.friendly = friendly
        this.id = null

        if (!objectId) {
            this.id = this.inferId()
        } else {
            this.id = parseInt(objectId, 16)

            const whitelist = new Set([
                ...WHITELISTED_MISMATCHING_IDS[0],
                ...(WHITELISTED_MISMATCHING_IDS[layer] || []),
            ])

            if (!whitelist.has(this.fullname)) {
                if (this.id !== this.inferId()) {
                    throw new Error(`Invalid inferred ID for ${this.repr()}`)
                }
            }
        }

        this.className = snakeToCamelCase(this.name, this.isFunction ? 'Request' : '')

        this.realArgs = this.sortedArgs().filter((a) => !(a.flagIndicator || a.genericDefinition))
    }

    get innermostResult() {
        const index = this.result.indexOf('<')
        return index === -1 ? this.result : this.result.slice(index + 1, -1)
    }

    /**
     * Returns the arguments properly sorted and ready to plug-in
     * into a Python's method header (i.e., flags and those which
     * can be inferred will go last so they can default =None)
     */
    sortedArgs() {
        return this.args.sort((x) => x.isFlag || x.canBeInferred)
    }

    repr(ignoreId) {
        let hexId
        let args

        if (this.id === null || ignoreId) {
            hexId = ''
        } else {
            hexId = `#${this.id.toString(16).padStart(8, '0')}`
        }

        if (this.args.length) {
            args = ` ${this.args.map((arg) => arg.toString()).join(' ')}`
        } else {
            args = ''
        }

        return `${this.fullname}${hexId}${args} = ${this.result}`
    }

    inferId() {
        const representation = this.repr(true)
            .replace(/(:|\?)bytes /g, '$1string ')
            .replace(/</g, ' ')
            .replace(/>|{|}/g, '')
            .replace(/ \w+:flags\.\d+\?true/g, '')

        if (this.fullname === 'inputMediaInvoice') {
            // eslint-disable-next-line no-empty
            if (this.fullname === 'inputMediaInvoice') {
            }
        }

        return crc32(Buffer.from(representation, 'utf8'))
    }

    toJson() {
        return {
            id: struct.unpack('i', struct.pack('I', this.id))[0].toString(),
            [this.isFunction ? 'method' : 'predicate']: this.fullname,
            param: this.args.filter((x) => !x.genericDefinition).map((x) => x.toJson()),
            type: this.result,
        }
    }

    isGoodExample() {
        return !this.className.endsWith('Empty')
    }

    asExample(f, indent) {
        f.write('<strong>new</strong> ')
        f.write(this.isFunction ? 'functions' : 'types')

        if (this.namespace) {
            f.write('.')
            f.write(this.namespace)
        }

        f.write('.')
        f.write(this.className)
        f.write('(')

        const args = this.realArgs.filter((arg) => !arg.omitExample())

        if (!args.length) {
            f.write(')')
            return
        }

        f.write('\n')
        indent++
        let remaining = args.length

        for (const arg of args) {
            remaining--
            f.write('    '.repeat(indent))
            f.write(arg.name)
            f.write('=')

            if (arg.isVector) {
                f.write('[')
            }

            arg.asExample(f, indent || 0)

            if (arg.isVector) {
                f.write(']')
            }

            if (remaining) {
                f.write(',')
            }

            f.write('\n')
        }

        indent--
        f.write('    '.repeat(indent))
        f.write(')')
    }
}

module.exports = {
    TLObject,
}