const { Role, MessageAttachment } = require('discord.js');
const { Command } = require('../../../../interfaces/');

const { Util } = require('../../../../../util/');
const { stripIndents } = require('common-tags');

const Constants = {
    pageSize: 9
};

class PermissionsCommand extends Command {

    constructor(client) {

        super(client, {
            name: 'permissions',
            module: 'administration',
            usage: "<list|role-name|user-name>",
            aliases: [
                'perms',
                'permission',
                'perm'
            ],
            examples: [
                "list",
                "Server Moderators",
                "@nolan#2887"
            ],
            arguments: [
                {
                    name: 'export',
                    type: 'BOOLEAN',
                    types: ['VERBAL', 'FLAG'],
                    default: true
                }
            ],
            // memberPermissions: ['ADMINISTRATOR', 'MANAGE_GUILD'],
            guildOnly: true
        });

    }

    async execute(message, { params, args }) {

        const _permissions = await message.guild.permissions();

        const permissions = [];
        for(const [key, value] of Object.entries(_permissions)) {
            if(value?.global?.length === 0 && Object.keys(value?.channels).length === 0) {
                await this._deletePermission(message.guild, key);
                continue;
            }

            if(!Number.isNaN(parseInt(key))) permissions.push({ ...value, id: key }); 
        } 
        
        if(args.export) {
            await this._displayRaw(message, permissions);
            return undefined;
        }

        if(params[0] === 'list') {
            await this._listAvailablePermissions(message);
            return undefined;
        }

        const parameters = params.join(' ');
        let resolveable = await this._parseResolveable(message, parameters);
        if(resolveable) {
            if(resolveable.user) resolveable = resolveable.user;

            const type = resolveable.tag ? 'user' : 'role';
            const permission = permissions[resolveable?.id || parameters];
    
            if(resolveable && !permission) {
                await message.respond(message.format('C_PERMISSIONS_PERMISSIONSNOTFOUND', { resolveable: resolveable.tag || resolveable.name, type, they: type === 'user' ? 'they ' : '' }), { emoji: 'failure' });
                return undefined;
            }
    
            if(!permission) {
                await message.respond(message.format('C_PERMISSIONS_NOTFOUND'), { emoji: 'failure' });
                return undefined;
            }
    
            const embed = {
                author: {
                    name: `${resolveable?.user?.tag || resolveable?.tag || resolveable?.name || parameters}'s Permissions`,
                    icon_url: resolveable.displayAvatarURL ? resolveable.displayAvatarURL() : message.guild.iconURL() //eslint-disable-line camelcase
                },
                description: `${message.format('C_PERMISSIONS_GLOBAL', { permissions: permission.global.length > 0 ? this._displayNames(permission.global).map((p) => `\`${p}\``).join(', ') : "`N/A`" })} ${Object.values(permission.channels).length > 0 ? message.format('C_PERMISSIONS_GLOBALALT') : ''}`,
                fields: []
            };
    
            let update = false;
            for(const [channelId, perms] of Object.entries(permission.channels)) {
                const channel = await this.client.resolver.resolveChannel(channelId, true, message.guild);
                if(!channel) {
                    delete permission.channels[channelId];
                    update = true;
                    continue;
                } else {
                    if(embed.fields.length === 25) {
                        embed.description += `\n${message.format('C_PERMISSIONS_MAXFIELDS')}`;
                        break;
                    }
                    embed.fields.push({
                        name: `#${channel.name}`,
                        value: this._displayNames(perms).map((p) => `\`${p}\``).join(', ')
                    });
                }
            }
            if(update) {
                delete permissions._id;
                try {
                    await this.client.storageManager.mongodb.permissions.updateOne(
                        { guildId: message.guild.id },
                        permissions
                    );
                } catch(error) {
                    this.client.logger.error(`Error removing channel permissions to ${message.guild.id}:\n${error.stack || error}`);
                }
            }
    
            return message.embed(embed); 
        }

        //End of displaying user/role permissions.
        let currentPage = 1;
        if(parameters.length > 0) {
            const number = parseInt(parameters[0]);
            if(!Number.isNaN(number) && number > 1) {
                currentPage = number;
            }
        }

        const size = permissions.length;
        if(size === 0) {
            return message.respond(message.format('C_PERMISSIONS_NOPERMISSIONS'), {
                emoji: 'failure'
            });
        }

        let { items, page, maxPage } = Util.paginate(permissions, currentPage, Constants.pageSize); //eslint-disable-line prefer-const

        const embed = {
            author: {
                name: `Guild Permissions`,
                icon_url: message.guild.iconURL() //eslint-disable-line camelcase
            },
            fields: [],
            footer: {
                text: `• Page ${page}/${maxPage} | ${size} Results`
            }
        };
        
        for(const item of items) {
            item.resolveable = await this._parseResolveable(message, item.id);
        }

        const display = (items) => {
            items = items.sort((a, b) => b.resolveable.display.length - a.resolveable.display.length);
            for(const item of items) {
                const field = {
                    name: item.resolveable.display,
                    value: this._displayNames(item.global).map((n) => `\`${n}\``).join('\n'),
                    inline: true
                };
    
                const channels = Object.keys(item.channels).length;
                if(channels > 0) {
                    field.value += `\n\`..${channels} channel${channels === 1 ? '' : 's'}\``;
                }
    
                embed.fields.push(field);
            }
        };

        display(items.filter((i) => i.resolveable instanceof Role));
        display(items.filter((i) => !(i.resolveable instanceof Role)));
        
        const empty = items.length % 3;
        for(let i = 0; i<empty; i++) {
            embed.fields.push({
                name: '\u200b',
                value: '\u200b',
                inline: true
            });
        }

        return message.embed(embed);

    }

    async _listAvailablePermissions(message) {

        const components = this.client.registry.components.filter((c) => c.type === 'command' || c.type === 'module' && c.components.some((c) => c.type === 'command'))
            .sort((a, b) => a - b);

        return message.respond(message.format('C_PERMISSIONS_LIST', { 
            permissions: components.map((c) => `\`${c.resolveable}\``).join(', ') 
        }), { emoji: 'success' });

    }

    async _parseResolveable(message, resolveable) {
        let parsed = await this.client.resolver.resolveRole(resolveable, true, message.guild);
        if(!parsed) {
            parsed = await this.client.resolver.resolveMember(resolveable, true, message.guild);
            if(!parsed) {
                parsed = await this.client.resolver.resolveUser(resolveable, true);
                if(!parsed) return null;
            }
        }
        return parsed;
    }

    async _displayRaw(message, permissions) {

        const string = JSON.stringify(permissions);
        const attachment = new MessageAttachment(Buffer.from(string), "permissions.json");

        return message.respond(message.format('C_PERMISSIONS_JSON'), { 
            emoji: 'success', 
            files: [ attachment ] 
        });

    }

    _displayNames(permissions) {

        const modules = this.client.registry.components.filter((c) => c.type === 'module');
        let names = [];

        let temp = [];
        for(const module of modules.values()) {
            for(const component of module.components.filter((c) => c.type === 'command').values()) {
                if(permissions.includes(component.resolveable)) {
                    temp.push(component.resolveable);
                }
            }
            temp.length === module.components.filter((c) => c.type === 'command').size //eslint-disable-line no-unused-expressions
                ? names.push(module.resolveable)
                : names = names.concat(temp);
            temp = [];
        }

        return names;

    }

    async _deletePermission(guild, key) {

        const permissions = guild._permissions;
        delete permissions[key];
        delete permissions._id;

        try {
            await this.client.storageManager.mongodb.permissions.updateOne(
                { guildId: guild.id },
                permissions
            ); 
        } catch(error) {
            return false;
        }

        return true;

    }


}

module.exports = PermissionsCommand;