using System;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using game.Account;

namespace game.PlayerDataStorage
{
    // The lease-only capability remains source-compatible with the independent 4B1 regression host.
    // This separate capability supplies every dependency required by a complete controlled load.
    internal sealed class PlayerKVGameLoadCapability
    {
        internal PlayerKVIdentitySnapshot Identity { get; }
        internal PlayerKVSchemaSnapshot Snapshot { get; }
        internal Uri Api { get; }
        internal string CacheRoot { get; }
        internal int LoginObserveMs { get; }
        internal int QuitObserveMs { get; }
        internal bool RequireExistingArchive { get; }
        internal Func<int,CancellationToken,Task> Delay { get; }
        internal PlayerKVControlledLoadCapability LeaseCapability { get; private set; }
        readonly PlayerKVControlledLoadCapability auth,kv,lease;
        readonly object gate=new object();
        CookieContainer cookies;
        HttpMessageHandler pendingKV,pendingLease;
        Exception cleanupFailure;
        readonly System.Collections.Generic.List<HttpMessageHandler> failedHandlers=new System.Collections.Generic.List<HttpMessageHandler>();
        bool claimed;
        private PlayerKVGameLoadCapability(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,Uri api,string cacheRoot,
            int loginMs,int quitMs,Func<int,CancellationToken,Task> delay,
            PlayerKVControlledLoadCapability auth,PlayerKVControlledLoadCapability kv,PlayerKVControlledLoadCapability lease,
            bool requireExistingArchive=false)
        {
            Identity=identity ?? throw new ArgumentNullException(nameof(identity)); Snapshot=snapshot ?? throw new ArgumentNullException(nameof(snapshot));
            if(api==null || !api.IsAbsoluteUri || (api.Scheme!="http" && api.Scheme!="https") || !string.IsNullOrEmpty(api.UserInfo) ||
                !string.IsNullOrEmpty(api.Query) || !string.IsNullOrEmpty(api.Fragment) || string.IsNullOrEmpty(cacheRoot) ||
                loginMs<1000 || loginMs>15000 || quitMs<1000 || quitMs>15000) throw new ArgumentException("Controlled load configuration invalid.");
            Api=new Uri(api.AbsoluteUri.TrimEnd('/')+"/"); CacheRoot=cacheRoot;
            LoginObserveMs=loginMs; QuitObserveMs=quitMs; Delay=delay ?? Task.Delay; this.auth=auth; this.kv=kv; this.lease=lease;
            RequireExistingArchive=requireExistingArchive;
        }
        internal static PlayerKVGameLoadCapability CreateForGame(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,
            Uri api,string cacheRoot,Func<CookieContainer,HttpMessageHandler> auth,Func<CookieContainer,HttpMessageHandler> kv,
            Func<CookieContainer,HttpMessageHandler> lease)
        {
            if(api==null || api.AbsoluteUri!="http://s101.local:18080/")
                throw new ArgumentException("Formal KV endpoint mismatch.",nameof(api));
            var capability=new PlayerKVGameLoadCapability(identity,snapshot,api,cacheRoot,10000,5000,null,
                PlayerKVControlledLoadCapability.CreateForGame(auth),PlayerKVControlledLoadCapability.CreateForGame(kv),
                PlayerKVControlledLoadCapability.CreateForGame(lease),true);
            capability.LeaseCapability=PlayerKVControlledLoadCapability.CreateForGame(capability.TakeLease);
            return capability;
        }
#if UNITY_EDITOR
        internal static PlayerKVGameLoadCapability CreateForValidation(PlayerKVIdentitySnapshot identity,PlayerKVSchemaSnapshot snapshot,
            Uri api,string cacheRoot,Func<CookieContainer,HttpMessageHandler> auth,Func<CookieContainer,HttpMessageHandler> kv,
            Func<CookieContainer,HttpMessageHandler> lease,int loginMs=10000,int quitMs=5000,Func<int,CancellationToken,Task> delay=null)
        {
            var capability=new PlayerKVGameLoadCapability(identity,snapshot,api,cacheRoot,loginMs,quitMs,delay,
                PlayerKVControlledLoadCapability.CreateForValidation(auth),PlayerKVControlledLoadCapability.CreateForValidation(kv),
                PlayerKVControlledLoadCapability.CreateForValidation(lease));
            capability.LeaseCapability=PlayerKVControlledLoadCapability.CreateForValidation(capability.TakeLease);
            return capability;
        }
#endif
        internal PlayerKVLoginContext CreateContext(string id,long epoch,Func<long,bool> current)
        {
            lock(gate) { if(claimed) throw new InvalidOperationException("Controlled capability already used."); claimed=true; }
            return new PlayerKVLoginContext(id,CacheRoot,epoch,current,Api,
                ()=>new S101AccountSession(Api,CreateAuthentication),()=>new PlayerKVGameSessionBridge(TakeKV));
        }
        HttpMessageHandler CreateAuthentication(CookieContainer jar)
        {
            lock(gate)
            {
                if(cookies!=null) throw new InvalidOperationException("Repeated authentication factory.");
                cookies=jar; HttpMessageHandler authentication=null;
                try
                {
                    // Validate all three returned handler graphs before the first authentication send.
                    authentication=auth.CreateHandler(jar); pendingKV=kv.CreateHandler(jar); pendingLease=lease.CreateHandler(jar);
                    if(ShareHandlerGraph(authentication,pendingKV,pendingLease))
                        throw new InvalidOperationException("Distinct transport ownership required.");
                    return authentication;
                }
                catch
                {
                    try { authentication?.Dispose(); } catch(Exception ex) { cleanupFailure=ex; failedHandlers.Add(authentication); }
                    try { CloseUnused(); } catch { }
                    throw;
                }
            }
        }
        static bool ShareHandlerGraph(params HttpMessageHandler[] roots)
        {
            var seen=new System.Collections.Generic.List<HttpMessageHandler>();
            foreach(var root in roots)
                for(var node=root;node!=null;node=(node as DelegatingHandler)?.InnerHandler)
                {
                    if(seen.Exists(previous=>ReferenceEquals(previous,node))) return true;
                    seen.Add(node);
                }
            return false;
        }
        HttpMessageHandler TakeKV(CookieContainer jar)
        {
            lock(gate)
            { if(!ReferenceEquals(jar,cookies) || pendingKV==null) throw new InvalidOperationException("KV transport ownership invalid.");
              var result=pendingKV; pendingKV=null; return result; }
        }
        HttpMessageHandler TakeLease(CookieContainer jar)
        {
            lock(gate)
            { if(!ReferenceEquals(jar,cookies) || pendingLease==null) throw new InvalidOperationException("Lease transport ownership invalid.");
              var result=pendingLease; pendingLease=null; return result; }
        }
        internal void CloseUnused()
        {
            lock(gate)
            {
                // Attempt every owned cleanup once; retain a failure even if a later Dispose succeeds.
                var ownedLease=pendingLease; pendingLease=null;
                var ownedKV=pendingKV; pendingKV=null;
                try { ownedLease?.Dispose(); } catch(Exception ex) { cleanupFailure=cleanupFailure ?? ex; failedHandlers.Add(ownedLease); }
                try { ownedKV?.Dispose(); } catch(Exception ex) { cleanupFailure=cleanupFailure ?? ex; failedHandlers.Add(ownedKV); }
                if(cleanupFailure!=null) throw new InvalidOperationException("Controlled transport cleanup failed.",cleanupFailure);
            }
        }
    }
}