/* $Id$ */

/** @file build.cpp Building support for the trolly AI. */

#include "../../stdafx.h"
#include "../../openttd.h"
#include "../../debug.h"
#include "../../road_map.h"
#include "../../command_func.h"
#include "trolly.h"
#include "../../engine_func.h"
#include "../../engine_base.h"
#include "../../variables.h"
#include "../../bridge.h"
#include "../../vehicle_func.h"
#include "../../vehicle_base.h"
#include "../../company_base.h"
#include "../../company_func.h"
#include "../ai.h"
#include "../../tunnelbridge.h"


// Build HQ
//  Params:
//    tile : tile where HQ is going to be build
bool AiNew_Build_CompanyHQ(Company *c, TileIndex tile)
{
	if (CmdFailed(AI_DoCommand(tile, 0, 0, DC_AUTO | DC_NO_WATER, CMD_BUILD_COMPANY_HQ)))
		return false;
	AI_DoCommand(tile, 0, 0, DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_BUILD_COMPANY_HQ);
	return true;
}


// Build station
//  Params:
//    type : AI_TRAIN/AI_BUS/AI_TRUCK : indicates the type of station
//    tile : tile where station is going to be build
//    length : in case of AI_TRAIN: length of station
//    numtracks : in case of AI_TRAIN: tracks of station
//    direction : the direction of the station
//    flag : flag passed to DoCommand (normally 0 to get the cost or DC_EXEC to build it)
CommandCost AiNew_Build_Station(Company *c, byte type, TileIndex tile, byte length, byte numtracks, byte direction, byte flag)
{
	if (type == AI_TRAIN)
		return AI_DoCommand(tile, (direction << 4) + (numtracks << 8) + (length << 16), INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_RAILROAD_STATION);

	if (type == AI_BUS)
		return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_BUS | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);

	return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_TRUCK | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);
}


// Builds a brdige. The second best out of the ones available for this company
//  Params:
//   tile_a : starting point
//   tile_b : end point
//   flag : flag passed to DoCommand
CommandCost AiNew_Build_Bridge(Company *c, TileIndex tile_a, TileIndex tile_b, byte flag)
{
	int bridge_type, bridge_len, type, type2;

	// Find a good bridgetype (the best money can buy)
	bridge_len = GetTunnelBridgeLength(tile_a, tile_b);
	type = type2 = 0;
	for (bridge_type = MAX_BRIDGES-1; bridge_type >= 0; bridge_type--) {
		if (CheckBridge_Stuff(bridge_type, bridge_len)) {
			type2 = type;
			type = bridge_type;
			// We found two bridges, exit
			if (type2 != 0) break;
		}
	}
	// There is only one bridge that can be built
	if (type2 == 0 && type != 0) type2 = type;

	// Now, simply, build the bridge!
	if (_companies_ainew[c->index].tbt == AI_TRAIN) {
		return AI_DoCommand(tile_a, tile_b, type2 | RAILTYPE_RAIL  << 8 | TRANSPORT_RAIL << 15, flag | DC_AUTO, CMD_BUILD_BRIDGE);
	} else {
		return AI_DoCommand(tile_a, tile_b, type2 | ROADTYPES_ROAD << 8 | TRANSPORT_ROAD << 15, flag | DC_AUTO, CMD_BUILD_BRIDGE);
	}
}


// Build the route part by part
// Basicly what this function do, is build that amount of parts of the route
//  that go in the same direction. It sets 'part' to the last part of the route builded.
//  The return value is the cost for the builded parts
//
//  Params:
//   PathFinderInfo : Pointer to the PathFinderInfo used for AiPathFinder
//   part : Which part we need to build
//
// TODO: skip already builded road-pieces (e.g.: cityroad)
CommandCost AiNew_Build_RoutePart(Company *c, Ai_PathFinderInfo *PathFinderInfo, byte flag)
{
	int part = PathFinderInfo->position;
	byte *route_extra = PathFinderInfo->route_extra;
	TileIndex *route = PathFinderInfo->route;
	int dir;
	int old_dir = -1;
	CommandCost cost;
	CommandCost res;
	// We need to calculate the direction with the parent of the parent.. so we skip
	//  the first pieces and the last piece
	if (part < 1) part = 1;
	// When we are done, stop it
	if (part >= PathFinderInfo->route_length - 1) {
		PathFinderInfo->position = -2;
		return CommandCost();
	}


	if (PathFinderInfo->rail_or_road) {
		// Tunnel code
		if ((AI_PATHFINDER_FLAG_TUNNEL & route_extra[part]) != 0) {
			cost.AddCost(AI_DoCommand(route[part], 0, 0, flag, CMD_BUILD_TUNNEL));
			PathFinderInfo->position++;
			// TODO: problems!
			if (CmdFailed(cost)) {
				DEBUG(ai, 0, "[BuildPath] tunnel could not be built (0x%X)", route[part]);
				return CommandCost();
			}
			return cost;
		}
		// Bridge code
		if ((AI_PATHFINDER_FLAG_BRIDGE & route_extra[part]) != 0) {
			cost.AddCost(AiNew_Build_Bridge(c, route[part], route[part - 1], flag));
			PathFinderInfo->position++;
			// TODO: problems!
			if (CmdFailed(cost)) {
				DEBUG(ai, 0, "[BuildPath] bridge could not be built (0x%X, 0x%X)", route[part], route[part - 1]);
				return CommandCost();
			}
			return cost;
		}

		// Build normal rail
		// Keep it doing till we go an other way
		if (route_extra[part - 1] == 0 && route_extra[part] == 0) {
			while (route_extra[part] == 0) {
				// Get the current direction
				dir = AiNew_GetRailDirection(route[part-1], route[part], route[part+1]);
				// Is it the same as the last one?
				if (old_dir != -1 && old_dir != dir) break;
				old_dir = dir;
				// Build the tile
				res = AI_DoCommand(route[part], 0, dir, flag, CMD_BUILD_SINGLE_RAIL);
				if (CmdFailed(res)) {
					// Problem.. let's just abort it all!
					_companies_ainew[c->index].state = AI_STATE_NOTHING;
					return CommandCost();
				}
				cost.AddCost(res);
				// Go to the next tile
				part++;
				// Check if it is still in range..
				if (part >= PathFinderInfo->route_length - 1) break;
			}
			part--;
		}
		// We want to return the last position, so we go back one
		PathFinderInfo->position = part;
	} else {
		// Tunnel code
		if ((AI_PATHFINDER_FLAG_TUNNEL & route_extra[part]) != 0) {
			cost.AddCost(AI_DoCommand(route[part], 0x200 | ROADTYPES_ROAD, 0, flag, CMD_BUILD_TUNNEL));
			PathFinderInfo->position++;
			// TODO: problems!
			if (CmdFailed(cost)) {
				DEBUG(ai, 0, "[BuildPath] tunnel could not be built (0x%X)", route[part]);
				return CommandCost();
			}
			return cost;
		}
		// Bridge code
		if ((AI_PATHFINDER_FLAG_BRIDGE & route_extra[part]) != 0) {
			cost.AddCost(AiNew_Build_Bridge(c, route[part], route[part + 1], flag));
			PathFinderInfo->position++;
			// TODO: problems!
			if (CmdFailed(cost)) {
				DEBUG(ai, 0, "[BuildPath] bridge could not be built (0x%X, 0x%X)", route[part], route[part + 1]);
				return CommandCost();
			}
			return cost;
		}

		// Build normal road
		// Keep it doing till we go an other way
		// EnsureNoVehicleOnGround makes sure we don't build on a tile where a vehicle is. This way
		//  it will wait till the vehicle is gone..
		if (route_extra[part-1] == 0 && route_extra[part] == 0 && (flag != DC_EXEC || EnsureNoVehicleOnGround(route[part]))) {
			while (route_extra[part] == 0 && (flag != DC_EXEC || EnsureNoVehicleOnGround(route[part]))) {
				// Get the current direction
				dir = AiNew_GetRoadDirection(route[part-1], route[part], route[part+1]);
				// Is it the same as the last one?
				if (old_dir != -1 && old_dir != dir) break;
				old_dir = dir;
				// There is already some road, and it is a bridge.. don't build!!!
				if (!IsTileType(route[part], MP_TUNNELBRIDGE)) {
					// Build the tile
					res = AI_DoCommand(route[part], dir, 0, flag | DC_NO_WATER, CMD_BUILD_ROAD);
					// Currently, we ignore CMD_ERRORs!
					if (CmdFailed(res) && flag == DC_EXEC && !IsTileType(route[part], MP_ROAD) && !EnsureNoVehicleOnGround(route[part])) {
						// Problem.. let's just abort it all!
						DEBUG(ai, 0, "[BuidPath] route building failed at tile 0x%X, aborting", route[part]);
						_companies_ainew[c->index].state = AI_STATE_NOTHING;
						return CommandCost();
					}

					if (CmdSucceeded(res)) cost.AddCost(res);
				}
				// Go to the next tile
				part++;
				// Check if it is still in range..
				if (part >= PathFinderInfo->route_length - 1) break;
			}
			part--;
			// We want to return the last position, so we go back one
		}
		if (!EnsureNoVehicleOnGround(route[part]) && flag == DC_EXEC) part--;
		PathFinderInfo->position = part;
	}

	return cost;
}


// This functions tries to find the best vehicle for this type of cargo
// It returns INVALID_ENGINE if not suitable engine is found
EngineID AiNew_PickVehicle(Company *c)
{
	if (_companies_ainew[c->index].tbt == AI_TRAIN) {
		// Not supported yet
		return INVALID_ENGINE;
	} else {
		EngineID best_veh_index = INVALID_ENGINE;
		int32 best_veh_rating = 0;
		const Engine *e;

		/* Loop through all road vehicles */
		FOR_ALL_ENGINES_OF_TYPE(e, VEH_ROAD) {
			EngineID i = e->index;
			const RoadVehicleInfo *rvi = &e->u.road;

			/* Skip vehicles which can't take our cargo type */
			if (rvi->cargo_type != _companies_ainew[c->index].cargo && !CanRefitTo(i, _companies_ainew[c->index].cargo)) continue;

			/* Skip trams */
			if (HasBit(EngInfo(i)->misc_flags, EF_ROAD_TRAM)) continue;

			// Is it availiable?
			// Also, check if the reliability of the vehicle is above the AI_VEHICLE_MIN_RELIABILTY
			if (!HasBit(e->company_avail, _current_company) || e->reliability * 100 < AI_VEHICLE_MIN_RELIABILTY << 16) continue;

			/* Rate and compare the engine by speed & capacity */
			int rating = rvi->max_speed * rvi->capacity;
			if (rating <= best_veh_rating) continue;

			// Can we build it?
			CommandCost ret = AI_DoCommand(0, i, 0, DC_QUERY_COST, CMD_BUILD_ROAD_VEH);
			if (CmdFailed(ret)) continue;

			best_veh_rating = rating;
			best_veh_index = i;
		}

		return best_veh_index;
	}
}


void CcAI(bool success, TileIndex tile, uint32 p1, uint32 p2)
{
	Company *c = GetCompany(_current_company);

	if (success) {
		_companies_ainew[c->index].state = AI_STATE_GIVE_ORDERS;
		_companies_ainew[c->index].veh_id = _new_vehicle_id;

		if (GetVehicle(_companies_ainew[c->index].veh_id)->cargo_type != _companies_ainew[c->index].cargo) {
			/* Cargo type doesn't match, so refit it */
			if (CmdFailed(DoCommand(tile, _companies_ainew[c->index].veh_id, _companies_ainew[c->index].cargo, DC_EXEC, CMD_REFIT_ROAD_VEH))) {
				/* Refit failed, so sell the vehicle */
				DoCommand(tile, _companies_ainew[c->index].veh_id, 0, DC_EXEC, CMD_SELL_ROAD_VEH);
				_companies_ainew[c->index].state = AI_STATE_NOTHING;
			}
		}
	} else {
		/* XXX this should be handled more gracefully */
		_companies_ainew[c->index].state = AI_STATE_NOTHING;
	}
}


// Builds the best vehicle possible
CommandCost AiNew_Build_Vehicle(Company *c, TileIndex tile, byte flag)
{
	EngineID i = AiNew_PickVehicle(c);

	if (i == INVALID_ENGINE) return CMD_ERROR;
	if (_companies_ainew[c->index].tbt == AI_TRAIN) return CMD_ERROR;

	if (flag & DC_EXEC) {
		return AI_DoCommandCc(tile, i, 0, flag, CMD_BUILD_ROAD_VEH, CcAI);
	} else {
		return AI_DoCommand(tile, i, 0, flag, CMD_BUILD_ROAD_VEH);
	}
}

CommandCost AiNew_Build_Depot(Company *c, TileIndex tile, DiagDirection direction, byte flag)
{
	CommandCost ret, ret2;
	if (_companies_ainew[c->index].tbt == AI_TRAIN) {
		return AI_DoCommand(tile, 0, direction, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_TRAIN_DEPOT);
	} else {
		ret = AI_DoCommand(tile, direction, 0, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_DEPOT);
		if (CmdFailed(ret2)) return ret;
		// Try to build the road from the depot
		ret2 = AI_DoCommand(tile + TileOffsByDiagDir(direction), DiagDirToRoadBits(ReverseDiagDir(direction)), 0, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD);
		// If it fails, ignore it..
		if (CmdFailed(ret2)) return ret;
		ret.AddCost(ret2);
		return ret;
	}
}