/*
 * mod-paragon — Paragon (class 12) class hooks
 *
 * See README for design. This file wires Player::IsClass / HasActivePowerType
 * so Paragon can reuse other classes' mechanics in narrowly scoped contexts.
 */

#include "Chat.h"
#include "Config.h"
#include "GameTime.h"
#include "Log.h"
#include "ObjectGuid.h"
#include "Player.h"
#include "ScriptMgr.h"
#include "SharedDefines.h"
#include "UnitDefines.h"
#include "WorldPacket.h"
#include "WorldSession.h"

#include <fmt/format.h>
#include <string>
#include <unordered_map>

class Paragon_PlayerScript : public PlayerScript
{
public:
    Paragon_PlayerScript() : PlayerScript("Paragon_PlayerScript", {
        PLAYERHOOK_ON_PLAYER_IS_CLASS,
        PLAYERHOOK_ON_PLAYER_HAS_ACTIVE_POWER_TYPE,
        PLAYERHOOK_ON_UPDATE,
        PLAYERHOOK_ON_LOGIN,
        PLAYERHOOK_ON_LOGOUT,
        PLAYERHOOK_ON_AFTER_UPDATE_MAX_POWER
    })
    {
        LOG_INFO("module", "[paragon] Paragon_PlayerScript registered "
                           "(MultiResource.HasActivePowers={})",
                 sConfigMgr->GetOption<bool>("Paragon.MultiResource.HasActivePowers", false));
    }

    [[nodiscard]] Optional<bool> OnPlayerIsClass(Player const* player, Classes unitClass, ClassContext context) override
    {
        if (!player || player->getClass() != CLASS_PARAGON)
            return std::nullopt;

        // Death Knight rune / runic power ability stack (narrow on purpose).
        if (unitClass == CLASS_DEATH_KNIGHT && context == CLASS_CONTEXT_ABILITY)
            return true;

        // Warrior ability stack: enables warrior-spec ability gates anywhere
        // they're checked. None of the currently-traced sites in core/scripts
        // gate on (CLASS_WARRIOR, CLASS_CONTEXT_ABILITY), so this is a safe
        // forward-compatible claim. Rage generation itself is gated on
        // HasActivePowerType(POWER_RAGE) and is wired below.
        if (unitClass == CLASS_WARRIOR && context == CLASS_CONTEXT_ABILITY)
            return true;

        // Reactive melee states: Overpower-on-dodge (warrior), Counterattack window (hunter).
        // We intentionally do NOT claim CLASS_ROGUE here: that context skips the generic
        // AURA_STATE_DEFENSE update on dodge (Riposte path) in Unit::ProcDamageAndSpellFor.
        if (context == CLASS_CONTEXT_ABILITY_REACTIVE)
        {
            if (unitClass == CLASS_WARRIOR || unitClass == CLASS_HUNTER)
                return true;
        }

        return std::nullopt;
    }

    [[nodiscard]] bool OnPlayerHasActivePowerType(Player const* player, Powers power) override
    {
        if (!player || player->getClass() != CLASS_PARAGON)
            return false;

        if (power == POWER_RUNIC_POWER || power == POWER_RUNE)
            return true;

        if (sConfigMgr->GetOption<bool>("Paragon.MultiResource.HasActivePowers", false))
        {
            switch (power)
            {
                case POWER_MANA:
                case POWER_RAGE:
                case POWER_ENERGY:
                case POWER_FOCUS:
                    return true;
                default:
                    break;
            }
        }

        return false;
    }

    // ChrClasses.dbc says POWER_RUNE has no pool (Unit::GetCreatePowers returns 0
    // for POWER_RUNE), so Player::InitStatsForLevel and the level-reset path
    // both clobber MaxPower(POWER_RUNE)=0 every login. The 3.3.5 client greys
    // the action button for any rune-cost spell when UnitPowerMax(player,
    // SPELL_POWER_RUNES) is 0 — visual rune pips can still animate via
    // PLAYER_RUNE_REGEN_*, but the spell stays unusable.
    //
    // Fix: pin POWER_RUNE max=8 (and current=8 in the easy spots) for Paragon
    // anywhere UpdateMaxPower runs. Rune availability is still authoritatively
    // tracked in m_runes; this just keeps the client engine happy.
    void OnPlayerAfterUpdateMaxPower(Player* player, Powers& power, float& value) override
    {
        if (!player || player->getClass() != CLASS_PARAGON)
            return;

        if (power == POWER_RUNE)
            value = 8.0f;
        else if (power == POWER_RUNIC_POWER)
            value = 1000.0f;
    }

    // Login: re-claim MaxPower for POWER_RUNE / POWER_RUNIC_POWER and seed
    // the rune state to the client. Player::LoadFromDB runs InitStatsForLevel
    // which calls Unit::SetMaxPower with the value from GetCreatePowers — and
    // GetCreatePowers returns 0 for POWER_RUNE (engine assumption: only DK has
    // runes; class is identified via getClass(), not IsClass()). So we have to
    // overwrite MaxPower here once the player is fully loaded. ResyncRunes is
    // a one-shot push so the rune frame is correct on first appearance.
    void OnPlayerLogin(Player* player) override
    {
        if (!player || player->getClass() != CLASS_PARAGON)
            return;

        player->SetMaxPower(POWER_RUNE, 8);
        if (player->GetMaxPower(POWER_RUNIC_POWER) <= 0)
            player->SetMaxPower(POWER_RUNIC_POWER, 1000);
        player->ResyncRunes(MAX_RUNES);

        ParagonRuneSyncState seed;
        seed.lastReadyMask = 0;
        for (uint8 i = 0; i < MAX_RUNES; ++i)
            if (player->GetRuneCooldown(i) == 0)
                seed.lastReadyMask |= (1u << i);
        runeSyncByGuid[player->GetGUID()] = seed;
    }

    void OnPlayerLogout(Player* player) override
    {
        if (!player)
            return;
        runeSyncByGuid.erase(player->GetGUID());
    }

    // Per-tick rune state pump for Paragon.
    //
    // Two responsibilities:
    //
    // 1. UNIT_FIELD_POWER5 (POWER_RUNE) tracks the live ready-rune count. The
    //    3.3.5 client's local "is this action usable" check on rune-cost
    //    spells reads UnitPower(player, SPELL_POWER_RUNES); for DK that's
    //    engine-managed but Paragon must own it.
    //
    // 2. Push SMSG_RESYNC_RUNES *only* on ready-bitmask transitions (rune
    //    consumed → on cd, or finished cd → ready). We deliberately do NOT
    //    push during the cooldown — Player::ResyncRunes encodes the per-rune
    //    "passed cooldown" byte as `255 - cd_ms * 51`, which is monotonic
    //    only for cd values in seconds (0..5). With cd in milliseconds the
    //    byte oscillates wildly tick-to-tick (cd=10000 → 207, cd=9000 → 7,
    //    cd=8000 → 63). Frequent resyncs feed the client garbage and freeze
    //    the rune frame. One mask-change resync is enough; sweeps run on the
    //    client's own 10s timer started from SMSG_SPELL_GO's CAST_FLAG_RUNE_LIST
    //    payload (which uses correct encoding) plus a Lua-side
    //    GetRuneCooldown poll in RuneFrame.lua.
    void OnPlayerUpdate(Player* player, uint32 /*p_time*/) override
    {
        if (!player || player->getClass() != CLASS_PARAGON)
            return;

        uint8 readyMask = 0;
        uint8 readyCount = 0;
        for (uint8 i = 0; i < MAX_RUNES; ++i)
        {
            if (player->GetRuneCooldown(i) == 0)
            {
                readyMask |= (1u << i);
                ++readyCount;
            }
        }

        if (uint32(readyCount) != player->GetPower(POWER_RUNE))
            player->SetPower(POWER_RUNE, readyCount);

        ParagonRuneSyncState& st = runeSyncByGuid[player->GetGUID()];
        if (readyMask != st.lastReadyMask)
        {
            player->ResyncRunes(MAX_RUNES);
            st.lastReadyMask = readyMask;

            // Authoritative rune CD pump (PARAA "R RUNES cd0 cd1 ... cd5",
            // ms remaining per slot, 0 = ready). The 3.3.5 client engine
            // class-gates SMSG_RESYNC_RUNES / SMSG_SPELL_GO RUNE_LIST to DK,
            // so the Paragon RuneFrame sim drives the visual entirely off
            // COMBAT_LOG_EVENT_UNFILTERED:SPELL_CAST_SUCCESS. The combat log
            // arrives ~100–200ms after the server already started the
            // cooldown, so the client's local timer trails the server. When
            // the user spams a rune spell, the server's slot refreshes
            // first, accepts the next cast, but the client UI still shows
            // CD remaining → "leak-through" past a greyed icon. Pushing the
            // actual remaining ms on every mask transition keeps the
            // visual locked to server state.
            std::string body = "R RUNES";
            for (uint8 i = 0; i < MAX_RUNES; ++i)
                body += " " + std::to_string(player->GetRuneCooldown(i));
            std::string const payload = std::string(kParagonAddonPrefix) + "\t" + body;
            WorldPacket runePkt;
            ChatHandler::BuildChatPacket(runePkt, CHAT_MSG_WHISPER, LANG_ADDON, player, player, payload);
            player->SendDirectMessage(&runePkt);
        }

        // Combo point pump: the 3.3.5 client engine class-gates SMSG_UPDATE_COMBO_POINTS
        // to rogue / druid, so the Paragon UI sim never sees CP changes from
        // Honor Among Thieves / Mutilate / etc. via either the engine state or
        // the client-side combat-log inference (HAT's 51699 trigger fires with a
        // null target and doesn't always emit SPELL_CAST_SUCCESS in the log).
        // Push the count over PARAA whenever it changes; the addon's combo
        // simulator listens for "R CP <n>" and overwrites paragonCP, so the
        // ComboFrame on the target frame paints reliably.
        int8 const cp = player->GetComboPoints();
        if (cp != st.lastCp)
        {
            std::string const payload = std::string(kParagonAddonPrefix) + "\t"
                                        + fmt::format("R CP {}", int32(cp));
            WorldPacket data;
            ChatHandler::BuildChatPacket(data, CHAT_MSG_WHISPER, LANG_ADDON, player, player, payload);
            player->SendDirectMessage(&data);
            st.lastCp = cp;
        }

        if (!sConfigMgr->GetOption<bool>("Paragon.Diag.RuneTrace", false))
            return;

        static thread_local time_t lastLogged = 0;
        time_t const wall = GameTime::GetGameTime().count();
        if (wall - lastLogged < 5)
            return;
        lastLogged = wall;

        std::string out;
        for (uint8 i = 0; i < MAX_RUNES; ++i)
        {
            char buf[64];
            snprintf(buf, sizeof(buf), "[%u: type=%u cur=%u cd=%u]",
                     i,
                     uint32(player->GetBaseRune(i)),
                     uint32(player->GetCurrentRune(i)),
                     uint32(player->GetRuneCooldown(i)));
            out += buf;
        }
        LOG_INFO("module", "[paragon-diag] {} runes: {} mask=0x{:02x}",
                 player->GetName(), out, uint32(readyMask));
    }

private:
    struct ParagonRuneSyncState
    {
        uint8 lastReadyMask{0xFFu}; // sentinel: no prior snapshot
        int8  lastCp{-1};            // sentinel: no prior snapshot
    };

    static constexpr char const* kParagonAddonPrefix = "PARAA";

    static std::unordered_map<ObjectGuid, ParagonRuneSyncState> runeSyncByGuid;
};

std::unordered_map<ObjectGuid, Paragon_PlayerScript::ParagonRuneSyncState> Paragon_PlayerScript::runeSyncByGuid;

void AddSC_paragon()
{
    new Paragon_PlayerScript();
}