using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;

using Server.Accounting;
using Server.Commands;
using Server.Engines.CityLoyalty;
using Server.Mobiles;
using Server.Multis;

namespace Server.Custom
{
    /// <summary>
    ///     Drives the shard from OUTSIDE the game, one verb per line in a file the driver polls.
    ///
    ///     Every other probe here runs a fixed script at boot or from `[command`, and both are the
    ///     wrong shape for an acceptance walk: a walk asserts what happened BETWEEN two steps
    ///     ("one mail, then nothing for a day"), so the steps have to be separated by the observer
    ///     rather than by a hard-coded delay -- and ServUO's console reads a fixed verb set
    ///     (`Scripts/Misc/ConsoleCommands.cs`), so `[p5probe` cannot be typed at a headless shard
    ///     at all. A file is the one channel a headless shard already has.
    ///
    ///     Write one or more lines to `Config/rigcmd.txt`; the driver runs them on the Core thread
    ///     within a second, prints `[RigDriver]` lines, and TRUNCATES the file so the next write is
    ///     the next command. Output is console-only: nothing here emits, and everything observed
    ///     travels the real bridge.
    ///
    ///     Verbs:
    ///       decaylist                        houses that CAN decay, with owner account and stage
    ///       decay &lt;serial|any&gt; &lt;stage&gt;       force a decay stage (LikeNew|Slightly|Somewhat|
    ///                                        Fairly|Greatly|IDOC|Collapsed)
    ///       vendorlist                       player vendors, with owner account and next pay time
    ///       vendorfunds &lt;serial&gt; &lt;gold&gt;      set a vendor's held gold (drives periodsRemaining)
    ///       citylist                         cities, governors and election phases
    ///       governor &lt;city&gt; &lt;mobile|none&gt;    seat a governor (a mobile serial, or a player's name)
    ///       election &lt;city&gt;                  force a new election into its nomination window
    ///       activate &lt;account&gt;               clear an account's inactivity, so its houses stop
    ///                                        being Condemned and CAN be refreshed
    ///       password &lt;account&gt; &lt;pw&gt;        set a game account's password (for a login probe)
    ///       worldgone &lt;serial&gt;               delete an object BEHIND the ownership registry's
    ///                                        back, playing the player who killed it
    ///       save                             a world save
    ///       shutdown                         a CLEAN shutdown, so the bridge emits server.shutdown
    ///
    ///     Test scaffolding. Never deployed; `deploy.ps1` copies only `overlay/`.
    /// </summary>
    public static class BridgeRigDriver
    {
        private static string _path;
        private static DateTime _lastWrite = DateTime.MinValue;

        public static void Initialize()
        {
            if (!Config.Get("Bridge.RigDriverEnabled", false))
                return;

            _path = Path.Combine(Core.BaseDirectory, "Config", "rigcmd.txt");

            CommandSystem.Register("rigdriver", AccessLevel.Administrator, e => Poll());

            Console.WriteLine("[RigDriver] watching {0}", _path);
            Timer.DelayCall(TimeSpan.FromSeconds(2.0), TimeSpan.FromSeconds(1.0), Poll);
        }

        // ---- the poll ----

        private static void Poll()
        {
            try
            {
                if (!File.Exists(_path))
                    return;

                // Written-and-not-finished is a real case: the observer writes with a shell
                // redirect while this timer fires. An empty file is nothing to do, and the
                // timestamp guard keeps a slow write from being run twice.
                var stamp = File.GetLastWriteTimeUtc(_path);
                if (stamp <= _lastWrite)
                    return;

                var lines = File.ReadAllLines(_path);
                if (lines.Length == 0)
                    return;

                _lastWrite = stamp;
                File.WriteAllText(_path, String.Empty);

                foreach (var line in lines)
                {
                    var trimmed = (line ?? String.Empty).Trim();
                    if (trimmed.Length == 0 || trimmed.StartsWith("#"))
                        continue;

                    try
                    {
                        Run(trimmed);
                    }
                    catch (Exception ex)
                    {
                        Say("\"" + trimmed + "\" threw: " + ex.Message);
                    }
                }

                Say("done");
            }
            catch (IOException)
            {
                // The writer still holds it. Next tick.
            }
            catch (Exception ex)
            {
                Say("poll threw: " + ex.Message);
            }
        }

        private static void Say(string line)
        {
            Console.WriteLine("[RigDriver] " + line);
        }

        private static void Run(string line)
        {
            var parts = line.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
            var verb = parts[0].ToLowerInvariant();

            switch (verb)
            {
                case "decaylist": DecayList(); break;
                case "decay": Decay(Arg(parts, 1), Arg(parts, 2)); break;
                case "vendorlist": VendorList(); break;
                case "vendorfunds": VendorFunds(Arg(parts, 1), Arg(parts, 2)); break;
                case "citylist": CityList(); break;
                case "governor": Governor(Arg(parts, 1), Arg(parts, 2)); break;
                case "election": Election(Arg(parts, 1)); break;
                case "activate": Activate(Arg(parts, 1)); break;
                case "password": Password(Arg(parts, 1), Arg(parts, 2)); break;
                // Phase 11b. Plays the interfering GM a config lease's compare-and-set exists to
                // catch, and reads a key back the way the game reads it. Both halves are here
                // rather than only in `[leaseprobe` because a headless rig has no client to type
                // a command at, and ServUO's own console takes a fixed verb set.
                case "configset": ConfigSet(Arg(parts, 1), Arg(parts, 2)); break;
                case "configread": ConfigRead(Arg(parts, 1)); break;
                // Kill credit inside a participation area. Lives in BridgeParticipationProbe
                // because it moves mobiles and spawns a creature; reachable from here because a
                // headless rig has no client to type `[partprobe` at. The two files ship together.
                case "partprobe":
                    BridgeParticipationProbe.Run(null, Arg(parts, 1), Int(Arg(parts, 2)), Int(Arg(parts, 3)));
                    break;
                // Phase 12a. `world.despawn` answering `gone` rather than `removed` is the
                // path a player takes every time they kill an event creature, and it is the one
                // outcome the rig cannot reach by asking the bridge: every bridge verb that
                // removes an object also drops its registry row, so the two never disagree.
                // This deletes the object and leaves the row, which is exactly what a sword does.
                case "worldgone": WorldGone(Arg(parts, 1)); break;
                case "save": Say("saving"); Misc.AutoSave.Save(); break;
                // A clean shutdown, which is the only kind that EMITS. `Stop-Process` drops the
                // socket and the shard says nothing, so a killed shard is indistinguishable from
                // a wedged one -- and `uo.server.down` never fires. Core.Kill runs
                // EventSink.Shutdown, which is what BridgeBoot listens on.
                case "shutdown": Say("shutting down"); Timer.DelayCall(TimeSpan.Zero, () => Core.Kill(false)); break;
                default: Say("unknown verb \"" + verb + "\""); break;
            }
        }

        /// <summary>
        ///     Deletes an object by serial, without telling anything.
        ///
        ///     Accepts the `0x…` form the bridge writes serials in, so a serial can be pasted
        ///     straight out of a `world.owned` reply.
        /// </summary>
        private static void WorldGone(string raw)
        {
            if (String.IsNullOrEmpty(raw))
            {
                Say("worldgone <serial>");
                return;
            }

            var text = raw.Trim();
            uint parsed;
            var ok = text.StartsWith("0x", StringComparison.OrdinalIgnoreCase)
                ? UInt32.TryParse(text.Substring(2), NumberStyles.HexNumber, CultureInfo.InvariantCulture, out parsed)
                : UInt32.TryParse(text, NumberStyles.Integer, CultureInfo.InvariantCulture, out parsed);

            if (!ok)
            {
                Say("worldgone: \"" + raw + "\" is not a serial");
                return;
            }

            var entity = World.FindEntity((Serial)unchecked((int)parsed));

            if (entity == null || entity.Deleted)
            {
                Say("worldgone: nothing at " + text);
                return;
            }

            entity.Delete();
            Say("worldgone: deleted " + text + " and told nobody");
        }

        private static string Arg(string[] parts, int i)
        {
            return i < parts.Length ? parts[i] : null;
        }

        private static int Int(string raw)
        {
            int n;
            return Int32.TryParse(raw, NumberStyles.Integer, CultureInfo.InvariantCulture, out n) ? n : 0;
        }

        /// <summary>
        ///     Writes a live config key, so a lease's `drifted` verdict can be produced at all.
        ///
        ///     **`Config.Set` has exactly ONE caller in the whole of ServUO 57.4**
        ///     (`Server/ScriptCompiler.cs`, for `Compiler.Dynamic`). No in-game command, gump or
        ///     console verb writes a config key, so on a stock shard a GM cannot drift a
        ///     configuration lease even deliberately -- and the one safety property a lease has
        ///     that nothing else does would go untested. Written through the same typed setter a
        ///     float lease uses, so what it produces is indistinguishable to the compare-and-set
        ///     from a real interfering write.
        ///
        ///     Deliberately no `Config.Save()`, matching BridgeLeases: nothing about a rig should
        ///     leave a modified .cfg behind for the next boot to inherit.
        /// </summary>
        private static void ConfigSet(string key, string raw)
        {
            if (key == null || raw == null)
            {
                Say("configset <key> <value>");
                return;
            }

            double n;

            if (Double.TryParse(raw, NumberStyles.Float, CultureInfo.InvariantCulture, out n))
                Config.Set(key, n);
            else
                Config.Set(key, raw);

            Say("configset " + key + " = " + raw + " (in memory only)");
        }

        /// <summary>
        ///     Reads a key back through `Config.Get`, at a moment long after every type
        ///     initialiser has run.
        ///
        ///     This is the check that tells a key which TOOK from one that only appeared to: a
        ///     lease on one of ServUO's ~150 cached call sites applies cleanly and does nothing,
        ///     which is the worst failure this feature has.
        /// </summary>
        private static void ConfigRead(string key)
        {
            if (key == null)
            {
                Say("configread <key>");
                return;
            }

            Say("configread " + key + " = " + Config.Get(key, Double.NaN).ToString("R", CultureInfo.InvariantCulture)
                + " (double), \"" + Config.Get(key, "<unset>") + "\" (string)");
        }

        // ---- houses ----

        /// <summary>
        ///     `CanDecay` is the filter, and getting it wrong is silent: an AutoRefresh house --
        ///     and the owner's newest house is always AutoRefresh -- has a DecayLevel getter that
        ///     calls ResetDynamicDecay(), so a forced stage is wiped before the sweep reads it and
        ///     NOTHING is emitted. That looks exactly like a broken emitter.
        /// </summary>
        private static IEnumerable<BaseHouse> Decayable()
        {
            return BaseHouse.AllHouses
                .Where(h => h != null && !h.Deleted && h.Owner != null && h.CanDecay);
        }

        private static void DecayList()
        {
            foreach (var h in Decayable())
            {
                var acct = h.Owner.Account == null ? "-" : h.Owner.Account.Username;
                Say(String.Format(
                    "house 0x{0:X} owner={1} acct={2} name=\"{3}\" region={4} type={5} level={6}",
                    h.Serial.Value, h.Owner.Name, acct, HouseName(h), RegionName(h),
                    h.DecayType, h.DecayLevel));
            }

            Say("decayable=" + Decayable().Count());
        }

        private static string HouseName(BaseHouse h)
        {
            return h.Sign != null && h.Sign.Name != null ? h.Sign.Name : String.Empty;
        }

        private static string RegionName(BaseHouse h)
        {
            var r = Region.Find(h.Location, h.Map);
            return r == null ? "-" : r.Name ?? "-";
        }

        private static void Decay(string which, string stage)
        {
            DecayLevel level;
            if (!TryParseStage(stage, out level))
            {
                Say("unknown stage \"" + stage + "\"");
                return;
            }

            BaseHouse house = null;

            if (String.IsNullOrEmpty(which) || which == "any")
                house = Decayable().FirstOrDefault();
            else
            {
                var serial = ParseSerial(which);
                house = Decayable().FirstOrDefault(h => h.Serial.Value == serial);
            }

            if (house == null)
            {
                Say("no decayable house matched \"" + which + "\"");
                return;
            }

            var from = house.DecayLevel;

            // A refresh is what a player does at the sign, and it is NOT SetDynamicDecay: the
            // level is derived from LastRefreshed, so a "LikeNew" that only rewrote the dynamic
            // stage would be undone by the next read.
            if (level == DecayLevel.LikeNew)
                house.RefreshDecay();
            else
                house.SetDynamicDecay(level);

            Say(String.Format(
                "house 0x{0:X} {1} -> {2} (now {3})",
                house.Serial.Value, from, level, house.DecayLevel));
        }

        private static bool TryParseStage(string s, out DecayLevel level)
        {
            level = DecayLevel.Ageless;
            if (String.IsNullOrEmpty(s))
                return false;

            foreach (DecayLevel candidate in Enum.GetValues(typeof(DecayLevel)))
            {
                if (String.Equals(candidate.ToString(), s, StringComparison.OrdinalIgnoreCase))
                {
                    level = candidate;
                    return true;
                }
            }

            return false;
        }

        private static int ParseSerial(string s)
        {
            var text = s.StartsWith("0x", StringComparison.OrdinalIgnoreCase) ? s.Substring(2) : s;
            int parsed;

            if (Int32.TryParse(text, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out parsed))
                return parsed;

            return Int32.TryParse(s, out parsed) ? parsed : 0;
        }

        // ---- vendors ----

        private static IEnumerable<PlayerVendor> Vendors()
        {
            return World.Mobiles.Values.OfType<PlayerVendor>().Where(v => !v.Deleted);
        }

        private static void VendorList()
        {
            Say("NewVendorSystem=" + BaseHouse.NewVendorSystem);

            foreach (var v in Vendors())
            {
                var owner = v.Owner;
                var acct = owner == null || owner.Account == null ? "-" : owner.Account.Username;
                Say(String.Format(
                    "vendor 0x{0:X} shop=\"{1}\" owner={2} acct={3} hold={4} charge={5} nextPay={6}",
                    v.Serial.Value, v.ShopName, owner == null ? "-" : owner.Name, acct,
                    v.HoldGold, v.ChargePerDay, v.NextPayTime.ToUniversalTime().ToString("o")));
            }

            Say("vendors=" + Vendors().Count());
        }

        /// <summary>
        ///     Set a vendor's held gold, which is the only knob that walks it toward dismissal
        ///     without waiting a pay period -- `NextPayTime` has a private setter, and a period is
        ///     a real day on the new vendor system and a UO day (~2 real hours) on the old one.
        ///     The emitter computes `periodsRemaining` as funds / chargePerPeriod, so this moves
        ///     exactly the field the threshold tracker watches.
        /// </summary>
        private static void VendorFunds(string which, string gold)
        {
            var serial = ParseSerial(which ?? String.Empty);
            var vendor = Vendors().FirstOrDefault(v => v.Serial.Value == serial);

            if (vendor == null)
            {
                Say("no vendor matched \"" + which + "\"");
                return;
            }

            int funds;
            if (!Int32.TryParse(gold, out funds))
            {
                Say("bad gold \"" + gold + "\"");
                return;
            }

            // Both, because the old vendor system spends BankAccount + HoldGold and the new one
            // spends HoldGold alone -- setting one would leave the other paying the charge.
            vendor.HoldGold = funds;
            vendor.BankAccount = 0;

            var charge = BaseHouse.NewVendorSystem ? vendor.ChargePerRealWorldDay : vendor.ChargePerDay;
            Say(String.Format(
                "vendor 0x{0:X} hold={1} bank=0 charge={2} periodsRemaining={3}",
                vendor.Serial.Value, vendor.HoldGold, charge, charge > 0 ? funds / charge : -1));
        }

        // ---- accounts ----

        /// <summary>
        ///     Mark an account as having just logged in.
        ///
        ///     This is the ONLY way to walk a decaying house back out of danger on a seeded
        ///     world, and the reason is ServUO's, not the rig's: every house that CAN decay here
        ///     is `DecayType.Condemned` (the seeder backdates accounts past
        ///     `Account.InactiveDuration` precisely to make them decay), and
        ///     `BaseHouse.RefreshDecay()` returns false immediately for a Condemned house. A
        ///     condemned house is not refreshable by anyone; it is rescued by its OWNER LOGGING
        ///     IN, which is what this reproduces.
        ///
        ///     What the shard then reports depends on how many houses the owner has:
        ///     `AutoRefresh` (their newest) stops decaying and reads **Ageless**, while an older
        ///     `ManualRefresh` one is back on the clock and reads **LikeNew**. Both are "out of
        ///     danger", and a mapper that reads only one of them misses most rescues.
        /// </summary>
        private static void Activate(string username)
        {
            var acct = Accounts.GetAccount(username) as Account;

            if (acct == null)
            {
                Say("no account \"" + username + "\"");
                return;
            }

            acct.LastLogin = DateTime.UtcNow;
            Say(String.Format("account {0} lastLogin=now inactive={1}", acct.Username, acct.Inactive));

            foreach (var h in BaseHouse.AllHouses)
            {
                if (h == null || h.Deleted || h.Owner == null || h.Owner.Account != acct)
                    continue;

                Say(String.Format(
                    "  house 0x{0:X} type={1} level={2}", h.Serial.Value, h.DecayType, h.DecayLevel));
            }
        }

        /// <summary>
        ///     Set a game account's password, so a login can be driven over a real socket.
        ///
        ///     The socket is not optional for the ACCEPTED half: ServUO's own AccountHandler calls
        ///     `acct.HasAccess(e.State)` before it ever checks the password, and a null NetState
        ///     fails that -- so an in-process probe reports "access denied" for a correct password
        ///     and can never produce `accepted:true`.
        /// </summary>
        private static void Password(string username, string pw)
        {
            var acct = Accounts.GetAccount(username) as Account;

            if (acct == null)
            {
                Say("no account \"" + username + "\"");
                return;
            }

            if (String.IsNullOrEmpty(pw))
            {
                Say("refusing to set an empty password");
                return;
            }

            acct.SetPassword(pw);
            Say("account " + acct.Username + " password set");
        }

        // ---- cities ----

        private static void CityList()
        {
            Say("CityLoyaltySystem.Enabled=" + CityLoyaltySystem.Enabled);

            foreach (var city in CityLoyaltySystem.Cities)
            {
                if (city == null)
                    continue;

                var e = city.Election;
                Say(String.Format(
                    "city={0} governor={1} elect={2} election={3} candidates={4} autoPick={5}",
                    city.City,
                    city.Governor == null ? "-" : city.Governor.Name + "/0x" + city.Governor.Serial.Value.ToString("X"),
                    city.GovernorElect == null ? "-" : city.GovernorElect.Name,
                    e == null ? "-" : (e.CanNominate() ? "nominate" : e.CanVote() ? "vote" : e.Ongoing ? "pending" : "none"),
                    e == null || e.Candidates == null ? 0 : e.Candidates.Count,
                    e == null ? "-" : e.AutoPickGovernor.ToUniversalTime().ToString("o")));
            }
        }

        private static CityLoyaltySystem FindCity(string name)
        {
            return CityLoyaltySystem.Cities.FirstOrDefault(
                c => c != null && String.Equals(c.City.ToString(), name, StringComparison.OrdinalIgnoreCase));
        }

        private static void Governor(string cityName, string who)
        {
            var city = FindCity(cityName);
            if (city == null)
            {
                Say("no city \"" + cityName + "\"");
                return;
            }

            if (String.Equals(who, "none", StringComparison.OrdinalIgnoreCase))
            {
                city.Governor = null;
                Say("city=" + city.City + " governor cleared");
                return;
            }

            var mob = FindMobile(who);
            if (mob == null)
            {
                Say("no player matched \"" + who + "\"");
                return;
            }

            city.Governor = mob;
            var acct = mob.Account == null ? "-" : mob.Account.Username;
            Say(String.Format(
                "city={0} governor={1} 0x{2:X} acct={3}",
                city.City, mob.Name, mob.Serial.Value, acct));
        }

        private static Mobile FindMobile(string who)
        {
            var serial = ParseSerial(who);

            if (serial != 0)
            {
                var bySerial = World.FindMobile(serial);
                if (bySerial != null)
                    return bySerial;
            }

            return World.Mobiles.Values.OfType<PlayerMobile>()
                .FirstOrDefault(m => !m.Deleted && String.Equals(m.Name, who, StringComparison.OrdinalIgnoreCase));
        }

        private static void Election(string cityName)
        {
            var city = FindCity(cityName);
            if (city == null)
            {
                Say("no city \"" + cityName + "\"");
                return;
            }

            if (city.Election == null)
            {
                Say("city=" + city.City + " has no election object");
                return;
            }

            city.Election.StartNewElection();
            Say(String.Format(
                "city={0} election restarted; autoPick={1} nominate={2}",
                city.City,
                city.Election.AutoPickGovernor.ToUniversalTime().ToString("o"),
                city.Election.CanNominate()));
        }
    }
}