using System;
using System.Collections.Generic;
using System.Reflection;
using HarmonyLib;
using Il2CppInterop.Runtime;
using Il2CppInterop.Runtime.InteropTypes;
using TMPro;
using UnityEngine.UI;

internal static class ClientTextRewrites
{
    private static readonly (string From, string To)[] Rules =
    {
        ("https://recroom.zendesk.com/home", "https://support.radicade.app/"),
        ("recroom.zendesk.com", "support.radicade.app"),
        ("https://www.recroom.com/privacy-policy/", "https://radicade.app/privacy-policy/"),
        ("https://recroom.com/terms-of-service", "https://radicade.app/terms-of-service/"),
        ("https://www.recroom.com/community/", "https://radicade.app/community/"),
    };

    private static readonly (string From, string To)[] ExactRules =
    {
        ("This account has been locked for security reasons. Contact us at recroom.zendesk.com.",
         LockedAccountSentence),
        ("This account has been locked for security reasons. Contact us at support.radicade.app.",
         LockedAccountSentence),
    };

    private const string GenericLoginFailure = "Login failed. Please try again.";
    private const string LockedAccountErrorCode = "ACCOUNT_PERMALOCKED";

    internal const string LockedAccountSentence =
        "This account has been locked for security reasons. Contact us at https://support.radicade.app.";

    private static bool _rewriting;

    internal static void Apply(Harmony harmony)
    {
        var mode = AsciiLower((Environment.GetEnvironmentVariable("RADICADE_CLIENT_TEXT") ?? string.Empty).Trim());
        if (mode == "0" || mode == "off")
        {
            return;
        }

        bool onEnable = mode.Length == 0 || mode == "1" || mode == "all" || mode == "onenable";
        bool onSet = mode.Length == 0 || mode == "1" || mode == "all" || mode == "settext";

        var seen = new HashSet<MethodBase>();
        var names = new List<string>();

        if (onEnable)
        {
            Hook(harmony, seen, names, AccessTools.Method(typeof(TextMeshProUGUI), "OnEnable"), nameof(GraphicEvent), "TextMeshProUGUI.OnEnable");
            Hook(harmony, seen, names, AccessTools.Method(typeof(Text), "OnEnable"), nameof(GraphicEvent), "UI.Text.OnEnable");
        }
        if (onSet)
        {
            Hook(harmony, seen, names, AccessTools.Method(typeof(TMP_Text), "set_text"), nameof(GraphicEvent), "TMP_Text.set_text");
            Hook(harmony, seen, names, AccessTools.Method(typeof(TMP_Text), "SetTextInternal"), nameof(GraphicEvent), "TMP_Text.SetTextInternal");
            Hook(harmony, seen, names, AccessTools.Method(typeof(Text), "set_text"), nameof(GraphicEvent), "UI.Text.set_text");
        }

        if (names.Count == 0)
            RadicadeEacBypassPlugin.LogSource.LogWarning("[ClientText] no text hooks could be installed (mode=" + (mode.Length == 0 ? "all" : mode) + "); the watch UI keeps its original text.");
    }

    private static void Hook(Harmony harmony, HashSet<MethodBase> seen, List<string> names,
        MethodBase target, string handler, string label)
    {
        if (target == null)
        {
            RadicadeEacBypassPlugin.LogSource.LogWarning("[ClientText] hook target missing: " + label);
            return;
        }
        if (!seen.Add(target)) return;

        try
        {
            var method = new HarmonyMethod(typeof(ClientTextRewrites)
                .GetMethod(handler, BindingFlags.Static | BindingFlags.NonPublic));
            harmony.Patch(target, postfix: method);
            names.Add(label);
        }
        catch (Exception ex)
        {
            RadicadeEacBypassPlugin.LogSource.LogWarning("[ClientText] could not hook " + label + ": "
                + ex.GetType().Name + ": " + ex.Message);
        }
    }

    private static void GraphicEvent(object __instance)
    {
        try
        {
            if (__instance is not Il2CppObjectBase obj) return;
            if (obj.TryCast<TMP_Text>() is { } tmp) { Fix(tmp); return; }
            if (obj.TryCast<Text>() is { } txt) { Fix(txt); }
        }
        catch { }
    }

    private static void Fix(TMP_Text instance)
    {
        try
        {
            if (instance == null || _rewriting) return;
            var current = instance.text;
            var rewritten = Rewrite(current);
            if (ReferenceEquals(current, rewritten) || string.Equals(rewritten, current, StringComparison.Ordinal)) return;
            _rewriting = true;
            try { instance.text = rewritten; } finally { _rewriting = false; }
        }
        catch { }
    }

    private static void Fix(Text instance)
    {
        try
        {
            if (instance == null || _rewriting) return;
            var current = instance.text;
            var rewritten = Rewrite(current);
            if (ReferenceEquals(current, rewritten) || string.Equals(rewritten, current, StringComparison.Ordinal)) return;
            _rewriting = true;
            try { instance.text = rewritten; } finally { _rewriting = false; }
        }
        catch { }
    }

    private static string Rewrite(string value)
    {
        if (string.IsNullOrEmpty(value)) return value;

        if (HubSocketAuth.LastLoginRefusalCode == LockedAccountErrorCode &&
            IndexOfAsciiIgnoreCase(value, GenericLoginFailure, 0) >= 0)
        {
            var locked = Replace(value, GenericLoginFailure, LockedAccountSentence);
            return locked;
        }

        if (IndexOfAsciiIgnoreCase(value, "recroom", 0) < 0 &&
            IndexOfAsciiIgnoreCase(value, "radicade", 0) < 0) return value;

        var result = value;
        foreach (var (from, to) in ExactRules)
            if (IndexOfAsciiIgnoreCase(result, from, 0) >= 0)
                result = Replace(result, from, to);

        foreach (var (from, to) in Rules)
            if (IndexOfAsciiIgnoreCase(result, from, 0) >= 0)
                result = Replace(result, from, to);

        return result;
    }

    private static string Replace(string source, string from, string to)
    {
        var sb = new System.Text.StringBuilder(source.Length);
        var i = 0;
        while (i < source.Length)
        {
            var hit = IndexOfAsciiIgnoreCase(source, from, i);
            if (hit < 0) { sb.Append(source, i, source.Length - i); break; }
            sb.Append(source, i, hit - i).Append(to);
            i = hit + from.Length;
        }
        return sb.ToString();
    }

    private static int IndexOfAsciiIgnoreCase(string haystack, string needle, int start)
    {
        if (haystack == null || needle == null) return -1;
        var n = needle.Length;
        var h = haystack.Length;
        if (n == 0) return start <= h ? start : -1;
        if (n > h) return -1;
        var last = h - n;
        for (var i = (start < 0 ? 0 : start); i <= last; i++)
        {
            var j = 0;
            while (j < n && LowerAscii(haystack[i + j]) == LowerAscii(needle[j])) j++;
            if (j == n) return i;
        }
        return -1;
    }

    private static char LowerAscii(char c) => c >= 'A' && c <= 'Z' ? (char)(c + 32) : c;

    private static string AsciiLower(string s)
    {
        for (var i = 0; i < s.Length; i++)
            if (s[i] >= 'A' && s[i] <= 'Z')
                return string.Create(s.Length, s, (span, state) =>
                {
                    for (var k = 0; k < state.Length; k++) span[k] = LowerAscii(state[k]);
                });
        return s;
    }

}