/*	EQEmu: EQEmulator

	Copyright (C) 2001-2026 EQEmu Development Team

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "common/rulesys.h"
#include "zone/map.h"
#include "zone/water_map.h"
#include "zone/zone.h"

extern Zone* zone;

#define FEAR_PATHING_DEBUG

int Mob::GetFleeRatio(Mob* other)
{
	int flee_ratio = GetSpecialAbility(SpecialAbility::FleePercent); // if a special SpecialAbility::FleePercent exists
	Mob *hate_top = GetHateTop();

	if (other != nullptr) {
		hate_top = other;
	}

	if (!hate_top) {
		return 0;
	}

	// If no special flee_percent check for Gray or Other con rates
	if (flee_ratio == 0) {
		flee_ratio = RuleI(Combat, FleeHPRatio);
		if (GetLevelCon(hate_top->GetLevel(), GetLevel()) == ConsiderColor::Gray && RuleB(Combat, FleeGray) &&
			GetLevel() <= RuleI(Combat, FleeGrayMaxLevel)) {
			flee_ratio = RuleI(Combat, FleeGrayHPRatio);
			LogFlee("Mob [{}] using combat flee gray flee_ratio [{}]", GetCleanName(), flee_ratio);
		}
	}

	return flee_ratio;
}

//this is called whenever we are damaged to process possible fleeing
void Mob::CheckFlee()
{
	if (IsPet() || IsCasting() || GetHP() == 0 || GetBodyType() == BodyType::Undead || (IsNPC() && CastToNPC()->IsUnderwaterOnly())) {
		return;
	}

	//if were already fleeing, we only need to check speed.  Speed changes will trigger pathing updates.
	if (flee_mode && currently_fleeing) {
		int flee_speed = GetFearSpeed();
		if (flee_speed < 1) {
			flee_speed = 0;
		}

		SetRunAnimSpeed(flee_speed);

		if (IsMoving() && flee_speed < 1) {
			StopNavigation();
		}

		return;
	}

	//dont bother if we are immune to fleeing
	if (GetSpecialAbility(SpecialAbility::FleeingImmunity) || spellbonuses.ImmuneToFlee) {
		LogFlee("Mob [{}] is immune to fleeing via special ability or spell bonus", GetCleanName());
		return;
	}

	int hp_ratio   = GetIntHPRatio();
	int flee_ratio = GetFleeRatio();
	Mob *hate_top  = GetHateTop();

	// Sanity Check for race conditions
	if(!hate_top) {
		//this should never happen...
		StartFleeing();
		return;
	}

	bool mob_has_low_enough_health_to_flee = hp_ratio >= flee_ratio;
	if (mob_has_low_enough_health_to_flee) {
		LogFlee(
			"Mob [{}] does not have low enough health to flee | hp_ratio [{}] flee_ratio [{}]",
			GetCleanName(),
			hp_ratio,
			flee_ratio
		);
		return;
	}

	// Sanity Check this should never happen...
	if (!hate_top) {
		currently_fleeing = true;
		StartFleeing();
		return;
	}

	int other_ratio = hate_top->GetIntHPRatio();
	// If the Client is nearing death the NPC will not flee and instead try to kill the client.
	if (other_ratio < 20) {
		return;
	}

	// Flee Chance checking based on con.
	uint32 con = GetLevelCon(hate_top->GetLevel(), GetLevel());
	int    flee_chance;
	switch (con) {
		//these values are not 100% researched
		case ConsiderColor::Gray:
			flee_chance = 100;
			break;
		case ConsiderColor::Green:
			flee_chance = 90;
			break;
		case ConsiderColor::LightBlue:
			flee_chance = 90;
			break;
		case ConsiderColor::DarkBlue:
			flee_chance = 80;
			break;
		default:
			flee_chance = 70;
			break;
	}

	LogFlee(
		"Post con-switch | Mob [{}] con [{}] hp_ratio [{}] flee_ratio [{}] flee_chance [{}]",
		GetCleanName(),
		con,
		hp_ratio,
		flee_ratio,
		flee_chance
	);

	// If we got here we are allowed to roll on flee chance if there is not other hated NPC's in the area.
	// SpecialAbility::AlwaysFlee, skip roll
	// if FleeIfNotAlone is true, we skip alone check
	// roll chance
	if (GetSpecialAbility(SpecialAbility::AlwaysFlee) ||
		((RuleB(Combat, FleeIfNotAlone) || entity_list.FleeAllyCount(hate_top, this) == 0) &&
		 zone->random.Roll(flee_chance))) {

		LogFlee(
			"Passed all checks to flee | Mob [{}] con [{}] hp_ratio [{}] flee_ratio [{}] flee_chance [{}]",
			GetCleanName(),
			con,
			hp_ratio,
			flee_ratio,
			flee_chance
		);

		currently_fleeing = true;
		StartFleeing();
	}
}

void Mob::StopFleeing()
{
	if (!flee_mode) {
		return;
	}

	flee_mode = false;

	//see if we are legitimately feared or blind now
	if (!spellbonuses.IsFeared && !IsBlind()) {
		currently_fleeing = false;
		StopNavigation();
	}
}

void Mob::FleeInfo(Mob* client)
{
	float other_ratio = client->GetHPRatio();
	bool wontflee = false;
	std::string reason;
	std::string flee;

	int allycount = entity_list.FleeAllyCount(client, this);

	if (flee_mode && currently_fleeing) {
		wontflee = true;
		reason = "NPC is already fleeing!";
	} else if (GetSpecialAbility(SpecialAbility::FleeingImmunity)) {
		wontflee = true;
		reason = "NPC is immune to fleeing.";
	} else if (other_ratio < 20) {
		wontflee = true;
		reason = "Player has low health.";
	} else if (GetSpecialAbility(SpecialAbility::AlwaysFlee)) {
		flee = "NPC has ALWAYS_FLEE set.";
	} else if (RuleB(Combat, FleeIfNotAlone) || (!RuleB(Combat, FleeIfNotAlone) && allycount == 0)) {
		flee = "NPC has no allies nearby or the rule to flee when not alone is enabled.";
	} else {
		wontflee = true;
		reason = "NPC likely has allies nearby.";
	}


	if (!wontflee) {
		client->Message(Chat::Green, "%s will flee at %d percent because %s", GetName(), GetFleeRatio(client), flee.c_str());
	} else {
		client->Message(Chat::Red, "%s will not flee because %s", GetName(), reason.c_str());
	}

	client->Message(Chat::Default, "NPC ally count %d", allycount);
}

void Mob::ProcessFlee()
{
	if (!flee_mode) {
		return;
	}

	//Stop fleeing if effect is applied after they start to run.
	//When ImmuneToFlee effect fades it will turn fear back on and check if it can still flee.
	if (flee_mode && (GetSpecialAbility(SpecialAbility::FleeingImmunity) || spellbonuses.ImmuneToFlee) &&
		!spellbonuses.IsFeared && !spellbonuses.IsBlind) {
		currently_fleeing = false;
		return;
	}

	Mob *hate_top = GetHateTop();
	bool dying = GetIntHPRatio() < GetFleeRatio();

	// We have stopped fleeing for an unknown reason (couldn't find a node is possible) restart.
	if (flee_mode && !currently_fleeing) {
		if(dying) {
			StartFleeing();
		}
	}

	//see if we are still dying, if so, do nothing
	if (dying) {
		return;
	}

	//we are not dying anymore, check to make sure we're not blind or feared and cancel flee.
	StopFleeing();
}

void Mob::CalculateNewFearpoint()
{
	// blind waypoint logic isn't the same as fear's.  Has a chance to run toward the player
	// chance is very high if the player is moving, otherwise it's low
	if (IsBlind() && !IsFeared() && GetTarget()) {
		int roll = 20;
		if (GetTarget()->GetCurrentSpeed() > 0.1f || (GetTarget()->IsClient() && GetTarget()->animation != 0)) {
			roll = 80;
		}

		if (zone->random.Roll(roll)) {
			m_FearWalkTarget = glm::vec3(GetTarget()->GetPosition());
			currently_fleeing = true;
			return;
		}
	}

	if (RuleB(Pathing, Fear) && zone->pathing) {
		glm::vec3 Node;
		int flags = PathingNotDisabled ^ PathingZoneLine;

		if (IsNPC() && CastToNPC()->IsUnderwaterOnly() && !zone->IsWaterZone(GetZOffset())) {
			Node = glm::vec3(0.0f);
		} else {
			Node = zone->pathing->GetRandomLocation(glm::vec3(GetX(), GetY(), GetZOffset()), flags);
		}

		if (Node.x != 0.0f || Node.y != 0.0f || Node.z != 0.0f) {
			Node.z = GetFixedZ(Node);
			PathfinderOptions opts;
			opts.smooth_path = true;
			opts.step_size = RuleR(Pathing, NavmeshStepSize);
			opts.offset = GetZOffset();
			opts.flags = flags;
			auto partial = false;
			auto stuck = false;
			auto route = zone->pathing->FindPath(
				glm::vec3(GetX(), GetY(), GetZOffset()),
				glm::vec3(Node.x, Node.y, Node.z),
				partial,
				stuck,
				opts
			);
			glm::vec3 last_good_loc = Node;
			int route_size = route.size();
			int route_count = 0;
			bool have_los = true;

			if (route_size == 2) {
				// FindPath() often fails to compute a route in some places, so to prevent running through walls we need to check LOS on all 2 node routes
				// size 2 route usually means FindPath() bugged out.  sometimes it returns locs outside the geometry
				if (CheckLosFN(Node.x, Node.y, Node.z, 6.0)) {
					LogPathingDetail("Direct route to fearpoint [{}], [{}], [{}] calculated for [{}]", last_good_loc.x, last_good_loc.y, last_good_loc.z, GetName());
					m_FearWalkTarget = last_good_loc;
					currently_fleeing = true;
					return;
				} else {
					LogPathingDetail("FindRoute() returned single hop route to destination without LOS: [{}], [{}], [{}] for [{}]", last_good_loc.x, last_good_loc.y, last_good_loc.z, GetName());
				}
				// use fallback logic if LOS fails
			} else if (!stuck) {
				// check route for LOS failures to prevent mobs ending up outside of playable area
				// only checking the last few hops because LOS will often fail in a valid route which can result in mobs getting undesirably trapped
				auto iter = route.begin();
				glm::vec3 previous_pos(GetX(), GetY(), GetZOffset());
				while (iter != route.end() && have_los == true) {
					auto &current_node = (*iter);
					iter++;
					route_count++;

					if (iter == route.end()) {
						continue;
					}

					previous_pos = current_node.pos;
					auto &next_node = (*iter);

					if (next_node.teleport) {
						continue;
					}

					if ((route_size - route_count) < 5 && !zone->zonemap->CheckLoS(previous_pos, next_node.pos)) {
						have_los = false;
						break;
					} else {
						last_good_loc = next_node.pos;
					}
				}

				if (have_los || route_count > 2) {
					if (have_los) {
						LogPathingDetail("Route to fearpoint [{}], [{}], [{}] calculated for [{}]; route size: [{}]", last_good_loc.x, last_good_loc.y, last_good_loc.z, GetName(), route_size);
					} else {
						LogPathingDetail("Using truncated route to fearpoint [{}], [{}], [{}] for [{}]; node count: [{}]; route size [{}]", last_good_loc.x, last_good_loc.y, last_good_loc.z, GetName(), route_count, route_size);
					}

					m_FearWalkTarget = last_good_loc;
					currently_fleeing = true;
					return;
				}
			}
		}
	}

	// fallback logic if pathing system can't be used
	bool inliquid = zone->HasWaterMap() && zone->watermap->InLiquid(glm::vec3(GetPosition())) || zone->IsWaterZone(GetZ());
	bool stay_inliquid = (inliquid && IsNPC() && CastToNPC()->IsUnderwaterOnly());
	bool levitating = IsClient() && (FindType(SpellEffect::Levitate) || flymode != GravityBehavior::Ground);
	bool open_outdoor_zone = !zone->CanCastOutdoor() && !zone->IsCity();

	int loop = 0;
	float ranx, rany, ranz;
	currently_fleeing = false;
	glm::vec3 myloc(GetX(), GetY(), GetZ());
	glm::vec3 myceil = myloc;
	float ceil = zone->zonemap->FindCeiling(myloc, &myceil);

	if (ceil != BEST_Z_INVALID) {
		ceil -= 1.0f;
	}

	while (loop < 100) { //Max 100 tries
		int ran = 250 - (loop * 2);
		loop++;

		if (open_outdoor_zone && loop < 20) { // try a distant loc first; other way will likely pick a close loc
			ranx = zone->random.Int(0, ran);
			rany = zone->random.Int(0, ran);
			if (ranx + rany < 200) {
				continue;
			}

			ranx = GetX() + (zone->random.Int(0, 1) == 1 ? ranx : -ranx);
			rany = GetY() + (zone->random.Int(0, 1) == 1 ? rany : -rany);
		} else {
			ranx = GetX() + zone->random.Int(0, ran - 1) - zone->random.Int(0, ran - 1);
			rany = GetY() + zone->random.Int(0, ran - 1) - zone->random.Int(0, ran - 1);
		}

		ranz = BEST_Z_INVALID;
		glm::vec3 newloc(ranx, rany, ceil != BEST_Z_INVALID ? ceil : GetZ());

		if (stay_inliquid || levitating || (loop > 50 && inliquid)) {
			if (zone->zonemap->CheckLoS(myloc, newloc)) {
				ranz = GetZ();
				currently_fleeing = true;
				break;
			}
		} else {
			if (ceil != BEST_Z_INVALID) {
				ranz = zone->zonemap->FindGround(newloc, &myceil);
			} else {
				ranz = zone->zonemap->FindBestZ(newloc, &myceil);
			}

			if (ranz != BEST_Z_INVALID) {
				ranz = SetBestZ(ranz);
			}
		}

		if (ranz == BEST_Z_INVALID) {
			continue;
		}

		float fdist = ranz - GetZ();
		if (fdist >= -50 && fdist <= 50 && CheckCoordLosNoZLeaps(GetX(), GetY(), GetZ(), ranx, rany, ranz)) {
			currently_fleeing = true;
			break;
		}
	}

	if (currently_fleeing) {
		m_FearWalkTarget = glm::vec3(ranx, rany, ranz);
		LogPathingDetail("Non-pathed fearpoint [{}], [{}], [{}] selected for [{}]", ranx, rany, ranz, GetName());
	}

	return;
}