/* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */

#ifndef COMMAND_H
#define COMMAND_H

#include <string>
#include <climits> // INT_MAX
#include <cstring> // memset

#include "System/creg/creg_cond.h"
#include "System/float3.h"



// ID's lower than 0 are reserved for build options (cmd -x = unitdefs[x])
#define CMD_STOP                   0
#define CMD_INSERT                 1
#define CMD_REMOVE                 2
#define CMD_WAIT                   5
#define CMD_TIMEWAIT               6
#define CMD_DEATHWAIT              7
#define CMD_SQUADWAIT              8
#define CMD_GATHERWAIT             9
#define CMD_MOVE                  10
#define CMD_PATROL                15
#define CMD_FIGHT                 16
#define CMD_ATTACK                20
#define CMD_AREA_ATTACK           21
#define CMD_GUARD                 25
#define CMD_AISELECT              30 //FIXME REMOVE
#define CMD_GROUPSELECT           35
#define CMD_GROUPADD              36
#define CMD_GROUPCLEAR            37
#define CMD_REPAIR                40
#define CMD_FIRE_STATE            45
#define CMD_MOVE_STATE            50
#define CMD_SETBASE               55
#define CMD_INTERNAL              60
#define CMD_SELFD                 65
#define CMD_LOAD_UNITS            75
#define CMD_LOAD_ONTO             76
#define CMD_UNLOAD_UNITS          80
#define CMD_UNLOAD_UNIT           81
#define CMD_ONOFF                 85
#define CMD_RECLAIM               90
#define CMD_CLOAK                 95
#define CMD_STOCKPILE            100
#define CMD_MANUALFIRE           105
#define CMD_RESTORE              110
#define CMD_REPEAT               115
#define CMD_TRAJECTORY           120
#define CMD_RESURRECT            125
#define CMD_CAPTURE              130
#define CMD_AUTOREPAIRLEVEL      135
#define CMD_IDLEMODE             145
#define CMD_FAILED               150

#define CMDTYPE_ICON                        0  // expect 0 parameters in return
#define CMDTYPE_ICON_MODE                   5  // expect 1 parameter in return (number selected mode)
#define CMDTYPE_ICON_MAP                   10  // expect 3 parameters in return (mappos)
#define CMDTYPE_ICON_AREA                  11  // expect 4 parameters in return (mappos+radius)
#define CMDTYPE_ICON_UNIT                  12  // expect 1 parameters in return (unitid)
#define CMDTYPE_ICON_UNIT_OR_MAP           13  // expect 1 parameters in return (unitid) or 3 parameters in return (mappos)
#define CMDTYPE_ICON_FRONT                 14  // expect 3 or 6 parameters in return (middle of front and right side of front if a front was defined)
#define CMDTYPE_ICON_UNIT_OR_AREA          16  // expect 1 parameter in return (unitid) or 4 parameters in return (mappos+radius)
#define CMDTYPE_NEXT                       17  // used with CMD_INTERNAL
#define CMDTYPE_PREV                       18  // used with CMD_INTERNAL
#define CMDTYPE_ICON_UNIT_FEATURE_OR_AREA  19  // expect 1 parameter in return (unitid or featureid+unitHandler.MaxUnits() (id>unitHandler.MaxUnits()=feature)) or 4 parameters in return (mappos+radius)
#define CMDTYPE_ICON_BUILDING              20  // expect 3 parameters in return (mappos)
#define CMDTYPE_CUSTOM                     21  // used with CMD_INTERNAL
#define CMDTYPE_ICON_UNIT_OR_RECTANGLE     22  // expect 1 parameter in return (unitid)
                                               //     or 3 parameters in return (mappos)
                                               //     or 6 parameters in return (startpos+endpos)
#define CMDTYPE_NUMBER                     23  // expect 1 parameter in return (number)


// wait codes
#define CMD_WAITCODE_TIMEWAIT    1.0f
#define CMD_WAITCODE_DEATHWAIT   2.0f
#define CMD_WAITCODE_SQUADWAIT   3.0f
#define CMD_WAITCODE_GATHERWAIT  4.0f


// bits for the option field of Command
// NOTE:
//   these names are misleading, eg. the SHIFT_KEY bit
//   really means that an order gets queued instead of
//   executed immediately (a better name for it would
//   be QUEUED_ORDER), ALT_KEY in most contexts means
//   OVERRIDE_QUEUED_ORDER, etc.
//
#define META_KEY        (1 << 2) //   4
#define INTERNAL_ORDER  (1 << 3) //   8
#define RIGHT_MOUSE_KEY (1 << 4) //  16
#define SHIFT_KEY       (1 << 5) //  32
#define CONTROL_KEY     (1 << 6) //  64
#define ALT_KEY         (1 << 7) // 128

// maximum number of inline parameters for any (default and custom) command type
#define MAX_COMMAND_PARAMS 8


#if defined(BUILDING_AI)
#define CMD_DGUN CMD_MANUALFIRE
#endif

enum {
	MOVESTATE_NONE     = -1,
	MOVESTATE_HOLDPOS  =  0,
	MOVESTATE_MANEUVER =  1,
	MOVESTATE_ROAM     =  2,
};
enum {
	FIRESTATE_NONE          = -1,
	FIRESTATE_HOLDFIRE      =  0,
	FIRESTATE_RETURNFIRE    =  1,
	FIRESTATE_FIREATWILL    =  2,
	FIRESTATE_FIREATNEUTRAL =  3,
};




#if (defined(__cplusplus))
extern "C" {
#endif

	// this must have C linkage
	struct RawCommand {
		int id[2];
		int timeOut;

		unsigned int pageIndex;
		unsigned int numParams;

		/// unique id within a CCommandQueue
		unsigned int tag;

		/// option bits (RIGHT_MOUSE_KEY, ...)
		unsigned char options;

		/// command parameters
		float* params;
	};

#if (defined(__cplusplus))
// extern "C"
};
#endif



struct Command {
private:
	CR_DECLARE_STRUCT(Command)

public:
	Command() {
		memset(&params[0], 0, sizeof(params));

		SetFlags(INT_MAX, 0, 0);
	}

	Command(const Command& c) {
		*this = c;
	}

	Command& operator = (const Command& c) {
		memcpy(&id[0], &c.id[0], sizeof(id));

		SetFlags(c.timeOut, c.tag, c.options);
		CopyParams(c);
		return *this;
	}

	Command(const float3& pos) {
		memset(&params[0], 0, sizeof(params));

		PushPos(pos);
		SetFlags(INT_MAX, 0, 0);
	}

	Command(int cmdID) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		SetFlags(INT_MAX, 0, 0);
	}

	Command(int cmdID, const float3& pos) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		PushPos(pos);
		SetFlags(INT_MAX, 0, 0);
	}

	Command(int cmdID, unsigned char cmdOptions) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		SetFlags(INT_MAX, 0, cmdOptions);
	}

	Command(int cmdID, unsigned char cmdOptions, float param) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		PushParam(param);
		SetFlags(INT_MAX, 0, cmdOptions);
	}

	Command(int cmdID, unsigned char cmdOptions, const float3& pos) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		PushPos(pos);
		SetFlags(INT_MAX, 0, cmdOptions);
	}

	Command(int cmdID, unsigned char cmdOptions, float param, const float3& pos) {
		memcpy(&id[0], &cmdID, sizeof(cmdID));
		memset(&params[0], 0, sizeof(params));

		PushParam(param);
		PushPos(pos);
		SetFlags(INT_MAX, 0, cmdOptions);
	}

	~Command();


	RawCommand ToRawCommand() {
		RawCommand rc;
		rc.id[0]   = id[0];
		rc.id[1]   = id[1];
		rc.timeOut = timeOut;

		rc.pageIndex = pageIndex;
		rc.numParams = numParams;
		rc.tag       = tag;
		rc.options   = options;

		rc.params    = const_cast<float*>(GetParams());
		return rc;
	}

	void FromRawCommand(const RawCommand& rc) {
		pageIndex = rc.pageIndex;
		numParams = rc.numParams;

		memcpy(&id[0], &rc.id[0], sizeof(id));
		memset(&params[0], 0, sizeof(params));

		SetFlags(rc.timeOut, rc.tag, rc.options);

		if (IsPooledCommand()) {
			// actual params should still be in pool, original command exists on AI side
			assert(numParams > MAX_COMMAND_PARAMS);
			return;
		}

		assert(numParams <= MAX_COMMAND_PARAMS);
		memcpy(&params[0], &rc.params[0], rc.numParams);
	}


	// returns true if the command references another object and
	// in this case also returns the param index of the object in cpos
	bool IsObjectCommand(int& cpos) const {
		switch (GetID()) {
			case CMD_ATTACK:
			case CMD_FIGHT:
			case CMD_MANUALFIRE:
				cpos = 0;
				return (1 <= numParams && numParams < 3);
			case CMD_GUARD:
			case CMD_LOAD_ONTO:
				cpos = 0;
				return (numParams >= 1);
			case CMD_CAPTURE:
			case CMD_LOAD_UNITS:
			case CMD_RECLAIM:
			case CMD_REPAIR:
			case CMD_RESURRECT:
				cpos = 0;
				return (1 <= numParams && numParams < 4);
			case CMD_UNLOAD_UNIT:
				cpos = 3;
				return (numParams >= 4);
			case CMD_INSERT: {
				if (numParams < 3)
					return false;

				Command icmd(static_cast<int>(GetParam(1)), static_cast<unsigned char>(GetParam(2)));

				for (unsigned int p = 3; p < numParams; p++) {
					icmd.PushParam(GetParam(p));
				}

				if (!icmd.IsObjectCommand(cpos))
					return false;

				cpos += 3;
				return true;
			}
		}

		return false;
	}

	bool IsMoveCommand() const {
		switch (GetID()) {
			case CMD_AREA_ATTACK:
			case CMD_ATTACK:
			case CMD_CAPTURE:
			case CMD_FIGHT:
			case CMD_GUARD:
			case CMD_LOAD_UNITS:
			case CMD_MANUALFIRE:
			case CMD_MOVE:
			case CMD_PATROL:
			case CMD_RECLAIM:
			case CMD_REPAIR:
			case CMD_RESTORE:
			case CMD_RESURRECT:
			case CMD_UNLOAD_UNIT:
			case CMD_UNLOAD_UNITS:
				return true;

			case CMD_DEATHWAIT:
			case CMD_GATHERWAIT:
			case CMD_SELFD:
			case CMD_SQUADWAIT:
			case CMD_STOP:
			case CMD_TIMEWAIT:
			case CMD_WAIT:
				return false;

			default: break;
		}

		// build commands are no different from reclaim or repair commands
		// in that they can require a unit to move, so return true when we
		// have one
		return IsBuildCommand();
	}

	bool IsAttackCommand() const {
		return (GetID() == CMD_ATTACK || GetID() == CMD_AREA_ATTACK || GetID() == CMD_FIGHT);
	}

	bool IsAreaCommand() const {
		switch (GetID()) {
			case CMD_CAPTURE:
			case CMD_LOAD_UNITS:
			case CMD_RECLAIM:
			case CMD_REPAIR:
			case CMD_RESURRECT:
				// params[0..2] always holds the position, params[3] the radius
				return (numParams == 4);
			case CMD_UNLOAD_UNITS:
				return (numParams == 5);
			case CMD_AREA_ATTACK:
				return true;

			default: break;
		}

		return false;
	}

	bool IsBuildCommand() const { return (GetID() < 0); }
	bool IsEmptyCommand() const { return (numParams == 0); }
	bool IsPooledCommand() const { return (pageIndex != -1u); } // implies numParams > MAX_COMMAND_PARAMS
	bool IsInternalOrder() const { return ((options & INTERNAL_ORDER) != 0); }

	int GetID(bool idx = false) const { return id[idx]; }
	int GetTimeOut() const { return timeOut; }
	unsigned int GetpageIndex() const { return pageIndex; }
	unsigned int GetNumParams() const { return numParams; }
	unsigned int GetTag() const { return tag; }
	unsigned char GetOpts() const { return options; }

	const float* GetParams(unsigned int idx = 0) const;
	      float  GetParam (unsigned int idx    ) const;


	bool SetParam(unsigned int idx, float param);
	bool PushParam(float param);

	bool PushPos(const float3& pos) { return (PushPos(&pos.x)); }
	bool PushPos(const float* pos) {
		PushParam(pos[0]);
		PushParam(pos[1]);
		PushParam(pos[2]);
		return true;
	}

	float3 GetPos(unsigned int idx) const {
		float3 p;
		p.x = GetParam(idx + 0);
		p.y = GetParam(idx + 1);
		p.z = GetParam(idx + 2);
		return p;
	}

	bool SetPos(unsigned int idx, const float3& p) {
		SetParam(idx + 0, p.x);
		SetParam(idx + 1, p.y);
		SetParam(idx + 2, p.z);
		return true;
	}

	void SetAICmdID(int cmdID) { id[1] = cmdID; }
	void SetTimeOut(int cmdTimeOut) { timeOut = cmdTimeOut; }
	void SetTag(unsigned int cmdTag) { tag = cmdTag; }
	void SetOpts(unsigned char cmdOpts) { options = cmdOpts; }
	void SetFlags(int cmdTimeOut, unsigned int cmdTag, unsigned char cmdOpts) {
		SetTimeOut(cmdTimeOut);
		SetTag(cmdTag);
		SetOpts(cmdOpts);
	}

	void CopyParams(const Command& c);

	void Serialize(creg::ISerializer* s);

private:
	/// [0] := CMD_xxx code (custom codes can also be used)
	/// [1] := AI Command callback id (passed in on handleCommand, returned in CommandFinished event)
	int id[2] = {0, -1};

	/**
	 * Remove this command after this frame (absolute).
	 * Mostly used for internal temporary orders, also
	 * exposed to Lua.
	 * Examples:
	 * - 0
	 * - MAX_INT
	 * - currenFrame + 60
	 */
	int timeOut = INT_MAX;

	/// page-index for cmdParamsPool, valid iff numParams > MAX_COMMAND_PARAMS
	unsigned int pageIndex = -1u;
	unsigned int numParams = 0;

	/// unique id within a CCommandQueue
	unsigned int tag = 0;

	/// option bits (RIGHT_MOUSE_KEY, ...)
	unsigned char options = 0;

	/// inline command parameters, used if numParams <= MAX_COMMAND_PARAMS
	float params[MAX_COMMAND_PARAMS];
};

#endif // COMMAND_H