using System;
using System.Collections.Generic;

using Server.Accounting;
using Server.Network;

namespace Server.Custom.Bridge
{
    /// <summary>
    ///     The staff write plane: moderation actions the website drives against the live shard.
    ///     Phase 1 verbs are admin.kick, admin.ban, admin.unban, admin.broadcast.
    ///
    ///     Every handler runs on the Core thread (BridgeBoot marshals inbound lines through
    ///     Timer.DelayCall first), so they may touch accounts, mobiles, and the network freely.
    ///
    ///     Trust model (https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/ADMIN_CONTROLS.md §5): authorization is enforced on the *website* —
    ///     these commands are gated there behind admin/moderator roles. The shard trusts the
    ///     loopback socket exactly as town-crier does, and applies inbound commands with an implicit
    ///     CoOwner authority. Its one hard floor is <see cref="Protected"/>: a command refuses any
    ///     target at or above BridgeConfig.AdminAccessFloor (default CoOwner), so a compromised or
    ///     buggy sidecar can never ban, kick, or otherwise touch the Owner.
    ///
    ///     The whole plane is opt-in: nothing here acts unless BridgeConfig.AdminWriteEnabled is set.
    ///     Attribution rides on a required "actor" field (the website staff user); every applied
    ///     action logs to the console and emits an admin.audit event the website persists.
    /// </summary>
    public static class BridgeAdmin
    {
        public static void Initialize()
        {
            if (!BridgeConfig.Enabled)
                return;

            BridgeBoot.RegisterHandler("admin.kick", OnKick);
            BridgeBoot.RegisterHandler("admin.ban", OnBan);
            BridgeBoot.RegisterHandler("admin.unban", OnUnban);
            BridgeBoot.RegisterHandler("admin.broadcast", OnBroadcast);
        }

        // ---- admin.kick ----

        /// <summary>Disconnects every live session of the target account. Target by serial or account.</summary>
        private static void OnKick(Dictionary<string, object> o)
        {
            var reqId = BridgeJson.GetString(o, "reqId");
            var actor = BridgeJson.GetString(o, "actor");
            const string action = "kick";

            if (!Ready(reqId, action, actor))
                return;

            var acct = ResolveTargetAccount(o);
            if (acct == null)
            {
                Err(reqId, action, "unknown or accountless target");
                return;
            }

            if (Protected(acct))
            {
                Err(reqId, action, "target is protected staff; refused");
                return;
            }

            int kicked = KickAccountSessions(acct);
            var reason = Reason(o);

            Log(actor, action, acct.Username, reason);
            BridgeLink.Emit(AuditBegin(action, actor, acct.Username)
                .Num("sessions", kicked)
                .Str("reason", reason)
                .End());

            var sb = BridgeJson.Begin("admin.ok");
            if (reqId != null) sb.Str("reqId", reqId);
            sb.Str("action", action).Str("target", acct.Username).Num("sessions", kicked);
            BridgeLink.Emit(sb.End());
        }

        // ---- admin.ban ----

        /// <summary>
        ///     Bans an account (offline-capable) and disconnects any live sessions. A positive
        ///     durationSec makes it a timed ban that auto-expires; zero/absent is indefinite. Mirrors
        ///     the in-game [ban path (KickCommand), but takes the duration explicitly instead of a gump.
        /// </summary>
        private static void OnBan(Dictionary<string, object> o)
        {
            var reqId = BridgeJson.GetString(o, "reqId");
            var actor = BridgeJson.GetString(o, "actor");
            const string action = "ban";

            if (!Ready(reqId, action, actor))
                return;

            var acct = ResolveTargetAccount(o);
            if (acct == null)
            {
                Err(reqId, action, "unknown or accountless target");
                return;
            }

            if (Protected(acct))
            {
                Err(reqId, action, "target is protected staff; refused");
                return;
            }

            int durationSec = BridgeJson.GetInt(o, "durationSec", 0);
            if (durationSec < 0)
                durationSec = 0;
            if (durationSec > BridgeConfig.AdminBanMaxDurationSec)
                durationSec = BridgeConfig.AdminBanMaxDurationSec;

            if (durationSec > 0)
                acct.SetBanTags(null, DateTime.UtcNow, TimeSpan.FromSeconds(durationSec));
            else
                acct.SetUnspecifiedBan(null); // clears any prior duration tags -> indefinite

            // SetBanTags/SetUnspecifiedBan(null) clear the BanDealer tag; set our own attribution.
            acct.SetTag("BanDealer", WebActor(actor));
            acct.Banned = true;

            int kicked = KickAccountSessions(acct);
            var reason = Reason(o);

            Log(actor, action, acct.Username, reason);
            BridgeLink.Emit(AuditBegin(action, actor, acct.Username)
                .Num("durationSec", durationSec)
                .Num("sessions", kicked)
                .Str("reason", reason)
                .End());

            var sb = BridgeJson.Begin("admin.ok");
            if (reqId != null) sb.Str("reqId", reqId);
            sb.Str("action", action).Str("target", acct.Username).Num("durationSec", durationSec).Num("sessions", kicked);
            BridgeLink.Emit(sb.End());
        }

        // ---- admin.unban ----

        private static void OnUnban(Dictionary<string, object> o)
        {
            var reqId = BridgeJson.GetString(o, "reqId");
            var actor = BridgeJson.GetString(o, "actor");
            const string action = "unban";

            if (!Ready(reqId, action, actor))
                return;

            var acct = ResolveTargetAccount(o);
            if (acct == null)
            {
                Err(reqId, action, "unknown or accountless target");
                return;
            }

            acct.Banned = false;
            acct.SetUnspecifiedBan(null); // clears BanTime/BanDuration/BanDealer tags

            var reason = Reason(o);

            Log(actor, action, acct.Username, reason);
            BridgeLink.Emit(AuditBegin(action, actor, acct.Username)
                .Str("reason", reason)
                .End());

            Ok(reqId, action, acct.Username);
        }

        // ---- admin.broadcast ----

        private static void OnBroadcast(Dictionary<string, object> o)
        {
            var reqId = BridgeJson.GetString(o, "reqId");
            var actor = BridgeJson.GetString(o, "actor");
            const string action = "broadcast";

            if (!Ready(reqId, action, actor))
                return;

            var text = BridgeJson.GetString(o, "text");
            if (String.IsNullOrEmpty(text))
            {
                Err(reqId, action, "missing text");
                return;
            }

            if (text.Length > BridgeConfig.AdminBroadcastMaxLength)
                text = text.Substring(0, BridgeConfig.AdminBroadcastMaxLength);

            // Default to the staff-broadcast green; callers may override.
            int hue = BridgeJson.GetInt(o, "hue", 0x35);

            World.Broadcast(hue, false, text);

            Log(actor, action, null, text);
            BridgeLink.Emit(AuditBegin(action, actor, null)
                .Num("hue", hue)
                .Str("text", text)
                .End());

            var sb = BridgeJson.Begin("admin.ok");
            if (reqId != null) sb.Str("reqId", reqId);
            sb.Str("action", action);
            BridgeLink.Emit(sb.End());
        }

        // ---- shared prologue / replies ----

        /// <summary>Common gate: the write plane must be enabled and an actor must be present.</summary>
        private static bool Ready(string reqId, string action, string actor)
        {
            if (!BridgeConfig.AdminWriteEnabled)
            {
                Err(reqId, action, "admin write plane disabled");
                return false;
            }

            if (String.IsNullOrEmpty(actor) || actor.Trim().Length == 0)
            {
                Err(reqId, action, "missing actor");
                return false;
            }

            return true;
        }

        private static void Ok(string reqId, string action, string target)
        {
            var sb = BridgeJson.Begin("admin.ok");
            if (reqId != null) sb.Str("reqId", reqId);
            sb.Str("action", action);
            if (target != null) sb.Str("target", target);
            BridgeLink.Emit(sb.End());
        }

        private static void Err(string reqId, string action, string reason)
        {
            var sb = BridgeJson.Begin("admin.error");
            if (reqId != null) sb.Str("reqId", reqId);
            if (action != null) sb.Str("action", action);
            sb.Str("reason", reason);
            BridgeLink.Emit(sb.End());
        }

        /// <summary>
        ///     Opens an admin.audit frame (origin=web) with the common fields. Broadcast to every
        ///     connected dashboard so the website's moderation log stays complete regardless of which
        ///     client issued the action. The in-game counterpart (origin=in-game) is emitted from
        ///     BridgeEvents; see https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/ADMIN_CONTROLS.md §5.5.
        /// </summary>
        private static System.Text.StringBuilder AuditBegin(string action, string actor, string target)
        {
            return BridgeJson.Begin("admin.audit")
                .Str("origin", "web")
                .Str("action", action)
                .Str("actor", WebActor(actor))
                .Str("target", target);
        }

        private static string WebActor(string actor)
        {
            return "web:" + actor;
        }

        /// <summary>Reads and length-clamps the optional reason string.</summary>
        private static string Reason(Dictionary<string, object> o)
        {
            var reason = BridgeJson.GetString(o, "reason");
            if (reason != null && reason.Length > BridgeConfig.AdminReasonMaxLength)
                reason = reason.Substring(0, BridgeConfig.AdminReasonMaxLength);
            return reason;
        }

        private static void Log(string actor, string action, string target, string detail)
        {
            Console.WriteLine("[Bridge][admin] {0} {1} target={2} detail={3}",
                WebActor(actor), action, target ?? "-", detail ?? "-");
        }

        // ---- target resolution & floor ----

        /// <summary>
        ///     Resolves the command's target account, by "serial" (a player mobile's account) or by
        ///     "account" (username). Returns null if neither resolves to a real account. Public so the
        ///     account plane (unlink) resolves targets the same way the moderation plane does.
        /// </summary>
        public static Account ResolveTargetAccount(Dictionary<string, object> o)
        {
            var serialStr = BridgeJson.GetString(o, "serial");
            if (serialStr != null)
            {
                var m = ResolveSerial(serialStr);
                return m == null ? null : m.Account as Account;
            }

            var acctName = BridgeJson.GetString(o, "account");
            return acctName == null ? null : Accounts.GetAccount(acctName) as Account;
        }

        /// <summary>
        ///     The one shard-side safety floor. Protects any account whose effective access level —
        ///     the account's own or the highest of its characters' — is at or above the configured
        ///     floor. Even under CoOwner authority the Owner is never reachable from the web. Public
        ///     so the account plane (unlink) enforces the identical floor.
        /// </summary>
        public static bool Protected(Account acct)
        {
            var lvl = acct.AccessLevel;

            for (int i = 0; i < acct.Length; i++)
            {
                var m = acct[i];
                if (m != null && m.AccessLevel > lvl)
                    lvl = m.AccessLevel;
            }

            return lvl >= BridgeConfig.AdminAccessFloor;
        }

        /// <summary>
        ///     Disconnects every live NetState bound to this account. Enumerating NetState.Instances
        ///     (rather than walking the account's characters) also catches a session parked at
        ///     character-select, which has an account but no mobile yet. Snapshot first, since Dispose
        ///     mutates the instance set.
        /// </summary>
        private static int KickAccountSessions(Account acct)
        {
            var doomed = new List<NetState>();

            foreach (var ns in NetState.Instances)
            {
                if (ns != null && ns.Account == acct)
                    doomed.Add(ns);
            }

            foreach (var ns in doomed)
                ns.Dispose();

            return doomed.Count;
        }

        private static Mobile ResolveSerial(string serialStr)
        {
            try
            {
                var s = serialStr.Trim();
                int value;

                if (s.StartsWith("0x", StringComparison.OrdinalIgnoreCase))
                    value = Convert.ToInt32(s.Substring(2), 16);
                else
                    value = Convert.ToInt32(s, 10);

                return World.FindMobile(value);
            }
            catch
            {
                return null;
            }
        }
    }
}