using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

using PluralKit.Core;

namespace PluralKit.Bot
{
    public class Random
    {
        private readonly IDatabase _db;
        private readonly ModelRepository _repo;
        private readonly EmbedService _embeds;

        private readonly global::System.Random randGen = new global::System.Random();

        public Random(EmbedService embeds, IDatabase db, ModelRepository repo)
        {
            _embeds = embeds;
            _db = db;
            _repo = repo;
        }

        // todo: get postgresql to return one random member/group instead of querying all members/groups

        public async Task Member(Context ctx)
        {
            ctx.CheckSystem();

            var members = await _repo.GetSystemMembers(ctx.System.Id).ToListAsync();

            if (!ctx.MatchFlag("all", "a"))
                members = members.Where(m => m.MemberVisibility == PrivacyLevel.Public).ToList();

            if (members == null || !members.Any())
                throw new PKError("Your system has no members! Please create at least one member before using this command.");

            var randInt = randGen.Next(members.Count);
            await ctx.Reply(embed: await _embeds.CreateMemberEmbed(ctx.System, members[randInt], ctx.Guild, ctx.LookupContextFor(ctx.System)));
        }

        public async Task Group(Context ctx)
        {
            ctx.CheckSystem();

            var groups = await _db.Execute(c => c.QueryGroupList(ctx.System.Id));
            if (!ctx.MatchFlag("all", "a"))
                groups = groups.Where(g => g.Visibility == PrivacyLevel.Public);

            if (groups == null || !groups.Any())
                throw new PKError("Your system has no groups! Please create at least one group before using this command.");

            var randInt = randGen.Next(groups.Count());
            await ctx.Reply(embed: await _embeds.CreateGroupEmbed(ctx, ctx.System, groups.ToArray()[randInt]));
        }

        public async Task GroupMember(Context ctx, PKGroup group)
        {
            var opts = ctx.ParseMemberListOptions(ctx.LookupContextFor(group.System));
            opts.GroupFilter = group.Id;

            await using var conn = await _db.Obtain();
            var members = await conn.QueryMemberList(ctx.System.Id, opts.ToQueryOptions());

            if (members == null || !members.Any())
                throw new PKError("This group has no members! Please add at least one member to this group before using this command.");

            if (!ctx.MatchFlag("all", "a"))
                members = members.Where(g => g.MemberVisibility == PrivacyLevel.Public);

            var ms = members.ToList();

            var randInt = randGen.Next(ms.Count);
            await ctx.Reply(embed: await _embeds.CreateMemberEmbed(ctx.System, ms[randInt], ctx.Guild, ctx.LookupContextFor(ctx.System)));
        }
    }
}