import * as Token from 'token-types';
import * as util from '../common/Util.js';
import { FrameParser } from './FrameParser.js';
import { ExtendedHeader, ID3v2Header, UINT32SYNCSAFE } from './ID3v2Token.js';
export class ID3v2Parser {
    static removeUnsyncBytes(buffer) {
        let readI = 0;
        let writeI = 0;
        while (readI < buffer.length - 1) {
            if (readI !== writeI) {
                buffer[writeI] = buffer[readI];
            }
            readI += (buffer[readI] === 0xFF && buffer[readI + 1] === 0) ? 2 : 1;
            writeI++;
        }
        if (readI < buffer.length) {
            buffer[writeI++] = buffer[readI];
        }
        return buffer.slice(0, writeI);
    }
    static getFrameHeaderLength(majorVer) {
        switch (majorVer) {
            case 2:
                return 6;
            case 3:
            case 4:
                return 10;
            default:
                throw new Error('header versionIndex is incorrect');
        }
    }
    static readFrameFlags(b) {
        return {
            status: {
                tag_alter_preservation: util.getBit(b, 0, 6),
                file_alter_preservation: util.getBit(b, 0, 5),
                read_only: util.getBit(b, 0, 4)
            },
            format: {
                grouping_identity: util.getBit(b, 1, 7),
                compression: util.getBit(b, 1, 3),
                encryption: util.getBit(b, 1, 2),
                unsynchronisation: util.getBit(b, 1, 1),
                data_length_indicator: util.getBit(b, 1, 0)
            }
        };
    }
    static readFrameData(uint8Array, frameHeader, majorVer, includeCovers, warningCollector) {
        const frameParser = new FrameParser(majorVer, warningCollector);
        switch (majorVer) {
            case 2:
                return frameParser.readData(uint8Array, frameHeader.id, includeCovers);
            case 3:
            case 4:
                if (frameHeader.flags.format.unsynchronisation) {
                    uint8Array = ID3v2Parser.removeUnsyncBytes(uint8Array);
                }
                if (frameHeader.flags.format.data_length_indicator) {
                    uint8Array = uint8Array.slice(4, uint8Array.length);
                }
                return frameParser.readData(uint8Array, frameHeader.id, includeCovers);
            default:
                throw new Error('Unexpected majorVer: ' + majorVer);
        }
    }
    /**
     * Create a combined tag key, of tag & description
     * @param tag e.g.: COM
     * @param description e.g. iTunPGAP
     * @returns string e.g. COM:iTunPGAP
     */
    static makeDescriptionTagName(tag, description) {
        return tag + (description ? ':' + description : '');
    }
    async parse(metadata, tokenizer, options) {
        this.tokenizer = tokenizer;
        this.metadata = metadata;
        this.options = options;
        const id3Header = await this.tokenizer.readToken(ID3v2Header);
        if (id3Header.fileIdentifier !== 'ID3') {
            throw new Error('expected ID3-header file-identifier \'ID3\' was not found');
        }
        this.id3Header = id3Header;
        this.headerType = ('ID3v2.' + id3Header.version.major);
        return id3Header.flags.isExtendedHeader ? this.parseExtendedHeader() : this.parseId3Data(id3Header.size);
    }
    async parseExtendedHeader() {
        const extendedHeader = await this.tokenizer.readToken(ExtendedHeader);
        const dataRemaining = extendedHeader.size - ExtendedHeader.len;
        return dataRemaining > 0 ? this.parseExtendedHeaderData(dataRemaining, extendedHeader.size) : this.parseId3Data(this.id3Header.size - extendedHeader.size);
    }
    async parseExtendedHeaderData(dataRemaining, extendedHeaderSize) {
        await this.tokenizer.ignore(dataRemaining);
        return this.parseId3Data(this.id3Header.size - extendedHeaderSize);
    }
    async parseId3Data(dataLen) {
        const uint8Array = await this.tokenizer.readToken(new Token.Uint8ArrayType(dataLen));
        for (const tag of this.parseMetadata(uint8Array)) {
            if (tag.id === 'TXXX') {
                if (tag.value) {
                    for (const text of tag.value.text) {
                        this.addTag(ID3v2Parser.makeDescriptionTagName(tag.id, tag.value.description), text);
                    }
                }
            }
            else if (tag.id === 'COM') {
                for (const value of tag.value) {
                    this.addTag(ID3v2Parser.makeDescriptionTagName(tag.id, value.description), value.text);
                }
            }
            else if (tag.id === 'COMM') {
                for (const value of tag.value) {
                    this.addTag(ID3v2Parser.makeDescriptionTagName(tag.id, value.description), value);
                }
            }
            else if (Array.isArray(tag.value)) {
                for (const value of tag.value) {
                    this.addTag(tag.id, value);
                }
            }
            else {
                this.addTag(tag.id, tag.value);
            }
        }
    }
    addTag(id, value) {
        this.metadata.addTag(this.headerType, id, value);
    }
    parseMetadata(data) {
        let offset = 0;
        const tags = [];
        while (true) {
            if (offset === data.length)
                break;
            const frameHeaderLength = ID3v2Parser.getFrameHeaderLength(this.id3Header.version.major);
            if (offset + frameHeaderLength > data.length) {
                this.metadata.addWarning('Illegal ID3v2 tag length');
                break;
            }
            const frameHeaderBytes = data.slice(offset, offset += frameHeaderLength);
            const frameHeader = this.readFrameHeader(frameHeaderBytes, this.id3Header.version.major);
            const frameDataBytes = data.slice(offset, offset += frameHeader.length);
            const values = ID3v2Parser.readFrameData(frameDataBytes, frameHeader, this.id3Header.version.major, !this.options.skipCovers, this.metadata);
            if (values) {
                tags.push({ id: frameHeader.id, value: values });
            }
        }
        return tags;
    }
    readFrameHeader(uint8Array, majorVer) {
        let header;
        switch (majorVer) {
            case 2:
                header = {
                    id: Buffer.from(uint8Array.slice(0, 3)).toString('ascii'),
                    length: Token.UINT24_BE.get(uint8Array, 3)
                };
                if (!header.id.match(/[A-Z0-9]{3}/g)) {
                    this.metadata.addWarning(`Invalid ID3v2.${this.id3Header.version.major} frame-header-ID: ${header.id}`);
                }
                break;
            case 3:
            case 4:
                header = {
                    id: Buffer.from(uint8Array.slice(0, 4)).toString('ascii'),
                    length: (majorVer === 4 ? UINT32SYNCSAFE : Token.UINT32_BE).get(uint8Array, 4),
                    flags: ID3v2Parser.readFrameFlags(uint8Array.slice(8, 10))
                };
                if (!header.id.match(/[A-Z0-9]{4}/g)) {
                    this.metadata.addWarning(`Invalid ID3v2.${this.id3Header.version.major} frame-header-ID: ${header.id}`);
                }
                break;
            default:
                throw new Error('Unexpected majorVer: ' + majorVer);
        }
        return header;
    }
}
