'use strict';

let imapTools = require('../imap-tools');

module.exports = {
    state: 'Selected',
    disableNotifications: true,

    schema: [{
        name: 'range',
        type: 'sequence'
    }, {
        name: 'extensions',
        type: 'array',
        optional: true
    }, {
        name: 'action',
        type: 'string'
    }, {
        name: 'flags',
        type: 'array'
    }],

    handler(command, callback) {

        // Check if STORE method is set
        if (typeof this._server.onStore !== 'function') {
            return callback(null, {
                response: 'NO',
                message: 'STORE not implemented'
            });
        }

        // Do nothing if in read only mode
        if (this.selected.readOnly) {
            return callback(null, {
                response: 'OK',
                message: 'STORE ignored with read-only mailbox'
            });
        }

        let type = 'flags'; // currently hard coded, in the future might support other values as well, eg. X-GM-LABELS
        let range = command.attributes[0] && command.attributes[0].value || '';

        // if arguments include extenstions at index 1, then length is 4, otherwise 3
        let pos = command.attributes.length === 4 ? 1 : 0;

        let action = (command.attributes[pos + 1] && command.attributes[pos + 1].value || '').toString().toUpperCase();

        let flags = [].
        concat(command.attributes[pos + 2] || []).
        map(flag => (flag && flag.value || '').toString());

        let unchangedSince = 0;
        let silent = false;

        // extensions are available as the optional argument at index 1
        let extensions = !pos ? [] : [].
        concat(command.attributes[pos] || []).
        map(val => (val && val.value));

        if (extensions.length) {
            if (extensions.length !== 2 || (extensions[0] || '').toString().toUpperCase() !== 'UNCHANGEDSINCE' || isNaN(extensions[1])) {
                return callback(new Error('Invalid modifier for STORE'));
            }
            unchangedSince = Number(extensions[1]);
            if (unchangedSince && !this.selected.condstoreEnabled) {
                this.condstoreEnabled = this.selected.condstoreEnabled = true;
            }
        }

        if (action.substr(-7) === '.SILENT') {
            action = action.substr(0, action.length - 7);
            silent = true;
        }

        if (!imapTools.validateSequnce(range)) {
            return callback(new Error('Invalid sequence set for STORE'));
        }

        if (!/^[\-+]?FLAGS$/.test(action)) {
            return callback(new Error('Invalid message data item name for STORE'));
        }

        switch (action.charAt(0)) {
            case '+':
                action = 'add';
                break;
            case '-':
                action = 'remove';
                break;
            default:
                action = 'set';
        }

        for (let i = flags.length - 1; i >= 0; i--) {
            if (flags[i].charAt(0) === '\\') {
                if (!imapTools.systemFlags.includes(flags[i].toLowerCase())) {
                    return callback(new Error('Invalid system flag argument for STORE'));
                } else {
                    // fix flag case
                    flags[i] = flags[i].toLowerCase().replace(/^\\./, c => c.toUpperCase());
                }
            }
            if (flags[i].length > 255) {
                return callback(new Error('Too long value for a flag'));
            }
        }

        // keep only unique flags
        flags = flags.filter((flag, i) => {
            if (i && flags.slice(0, i).indexOf(flag) >= 0) {
                return false;
            }
            return true;
        });

        let messages = imapTools.getMessageRange(this.selected.uidList, range, false);

        this._server.onStore(this.selected.mailbox, {
            value: flags,
            action,
            type,
            silent,
            messages,
            unchangedSince
        }, this.session, (err, success, modified) => {
            if (err) {
                return callback(err);
            }

            // STORE returns MODIFIED as sequence numbers, so convert UIDs to sequence list
            if (modified && modified.length) {
                modified = modified.
                map(uid => this.selected.uidList.indexOf(uid) + 1).
                filter(seq =>
                    // ensure that deleted items (eg seq=0) do not end up in the list
                    seq > 0
                );
            }

            let message = success === true ? 'STORE completed' : false;
            if (modified && modified.length) {
                message = 'Conditional STORE failed';
            } else if (message && unchangedSince) {
                message = 'Conditional STORE completed';
            }

            let response = {
                response: success === true ? 'OK' : 'NO',
                code: typeof success === 'string' ? success.toUpperCase() : (modified && modified.length ? 'MODIFIED ' + imapTools.packMessageRange(modified) : false),
                message
            };

            // check if only messages that exist are referenced
            if (!this._server.options.allowStoreExpunged && success === true && !silent && messages.length) {
                for (let i = this.selected.notifications.length - 1; i >= 0; i--) {
                    if (this.selected.notifications[i].command === 'EXPUNGE' && messages.indexOf(this.selected.notifications[i].uid) >= 0) {
                        response = {
                            response: 'NO',
                            message: 'Some of the messages no longer exist'
                        };
                        break;
                    }
                }
            }

            callback(null, response);

        });
    }
};