/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 "ags/shared/ac/character_info.h"
#include "ags/shared/ac/common.h"
#include "ags/shared/ac/game_setup_struct.h"
#include "ags/engine/ac/character.h"
#include "ags/engine/ac/character_extras.h"
#include "ags/engine/ac/game_state.h"
#include "ags/engine/ac/global_character.h"
#include "ags/engine/ac/global_game.h"
#include "ags/engine/ac/math.h"
#include "ags/engine/ac/object.h"
#include "ags/engine/ac/view_frame.h"
#include "ags/engine/debugging/debug_log.h"
#include "ags/shared/game/room_struct.h"
#include "ags/engine/main/update.h"
#include "ags/engine/media/audio/audio_system.h"
#include "ags/ags.h"
#include "ags/globals.h"

namespace AGS3 {

using namespace AGS::Shared;

#define Random __Rand

int CharacterInfo::get_baseline() const {
	if (baseline < 1)
		return y;
	return baseline;
}

int CharacterInfo::get_blocking_top() const {
	if (blocking_height > 0)
		return y - blocking_height / 2;
	return y - 2;
}

int CharacterInfo::get_blocking_bottom() const {
	// the blocking_bottom should be 1 less than the top + height
	// since the code does <= checks on it rather than < checks
	if (blocking_height > 0)
		return (y + (blocking_height + 1) / 2) - 1;
	return y + 3;
}

void CharacterInfo::FixupCurrentLoopAndFrame() {
	// If current loop property exceeds number of loops,
	// or if selected loop has no frames, then try select any first loop that has frames.
	// NOTE: although this may seem like a weird solution to a problem,
	// we do so for backwards compatibility; this approximately emulates older games behavior.

	if (view >= 0 &&
		(loop >= _GP(views)[view].numLoops || _GP(views)[view].loops[loop].numFrames == 0)) {
		for (loop = 0;
			(loop < _GP(views)[view].numLoops) && (_GP(views)[view].loops[loop].numFrames == 0); ++loop) {
		}
		if (loop == _GP(views)[view].numLoops) {
			// view has no frames?!
			// amazingly enough there are old games that allow this to happen...
			if (_G(loaded_game_file_version) >= kGameVersion_300)
				quitprintf("!Character %s is assigned view %d that has no frames!", scrname, view);
			loop = 0;
		}
	}

	// If the last saved frame exceeds a new loop, then switch to frame 1
	// (first walking frame) if walking, or frame 0 otherwise or if there's less than 2 frames.
	int frames_in_loop = _GP(views)[view].loops[loop].numFrames;
	if (frame >= frames_in_loop) {
		frame = (walking > 0 && frames_in_loop > 1) ? 1 : 0;
	}
}

void CharacterInfo::UpdateMoveAndAnim(int &char_index, CharacterExtras *chex, std::vector<int> &followingAsSheep) {
	int res;

	if (on != 1)
		return;

	// Turn around during walk
	res = update_character_walkturning(chex);
	// Fixup character's loop prior to any further logic updates
	FixupCurrentLoopAndFrame();

	// FIXME: refactor this nonsense!
	// [IKM] Yes, it should return! upon getting RETURN_CONTINUE here
	if (res == RETURN_CONTINUE) { // [IKM] now, this is one of those places...
		return;                   //  must be careful not to screw things up
	}

	int doing_nothing = 1;
	update_character_moving(char_index, chex, doing_nothing);

	// [IKM] 2012-06-28:
	// Character index value is used to set up some variables in there, so I cannot just cease using it
	res = update_character_animating(char_index, doing_nothing);
	// [IKM] Yes, it should return! upon getting RETURN_CONTINUE here
	if (res == RETURN_CONTINUE) { // [IKM] now, this is one of those places...
		return;                   //  must be careful not to screw things up
	}

	update_character_follower(char_index, followingAsSheep, doing_nothing);

	update_character_idle(chex, doing_nothing);

	chex->process_idle_this_time = 0;
}

void CharacterInfo::UpdateFollowingExactlyCharacter() {
	x = _GP(game).chars[following].x;
	y = _GP(game).chars[following].y;
	z = _GP(game).chars[following].z;
	room = _GP(game).chars[following].room;
	prevroom = _GP(game).chars[following].prevroom;

	int usebase = _GP(game).chars[following].get_baseline();

	if (flags & CHF_BEHINDSHEPHERD)
		baseline = usebase - 1;
	else
		baseline = usebase + 1;
}

int CharacterInfo::update_character_walkturning(CharacterExtras *chex) {
	if (walking >= TURNING_AROUND) {
		// Currently rotating to correct direction
		if (walkwait > 0) walkwait--;
		else {
			// Work out which direction is next
			int wantloop = find_looporder_index(loop) + 1;
			// going anti-clockwise, take one before instead
			if (walking >= TURNING_BACKWARDS)
				wantloop -= 2;
			while (1) {
				if (wantloop >= 8)
					wantloop = 0;
				if (wantloop < 0)
					wantloop = 7;
				if ((turnlooporder[wantloop] >= _GP(views)[view].numLoops) ||
				        (_GP(views)[view].loops[turnlooporder[wantloop]].numFrames < 1) ||
				        ((turnlooporder[wantloop] >= 4) && ((flags & CHF_NODIAGONAL) != 0))) {
					if (walking >= TURNING_BACKWARDS)
						wantloop--;
					else
						wantloop++;
				} else break;
			}
			loop = turnlooporder[wantloop];
			walking -= TURNING_AROUND;
			// if still turning, wait for next frame
			if (walking % TURNING_BACKWARDS >= TURNING_AROUND)
				walkwait = animspeed;
			else
				walking = walking % TURNING_BACKWARDS;
			chex->animwait = 0;
		}
		return RETURN_CONTINUE;
		//continue;
	}

	return 0;
}

void CharacterInfo::update_character_moving(int &char_index, CharacterExtras *chex, int &doing_nothing) {
	if ((walking > 0) && (room == _G(displayed_room))) {
		if (walkwait > 0) walkwait--;
		else {
			flags &= ~CHF_AWAITINGMOVE;

			// Move the character
			int numSteps = wantMoveNow(this, chex);

			if ((numSteps) && (chex->xwas != INVALID_X)) {
				// if the zoom level changed mid-move, the walkcounter
				// might not have come round properly - so sort it out
				x = chex->xwas;
				y = chex->ywas;
				chex->xwas = INVALID_X;
			}

			int oldxp = x, oldyp = y;

			for (int ff = 0; ff < abs(numSteps); ff++) {
				if (doNextCharMoveStep(this, char_index, chex))
					break;
				if ((walking == 0) || (walking >= TURNING_AROUND))
					break;
			}

			if (numSteps < 0) {
				// very small scaling, intersperse the movement
				// to stop it being jumpy
				chex->xwas = x;
				chex->ywas = y;
				x = ((x) - oldxp) / 2 + oldxp;
				y = ((y) - oldyp) / 2 + oldyp;
			} else if (numSteps > 0)
				chex->xwas = INVALID_X;

			if ((flags & CHF_ANTIGLIDE) == 0)
				walkwaitcounter++;
		}

		// Fixup character's loop, it may be changed when making a walk-move
		FixupCurrentLoopAndFrame();

		doing_nothing = 0; // still walking?

		if (walking < 1) {
			// Finished walking, stop and reset state
			chex->process_idle_this_time = 1;
			doing_nothing = 1;
			walkwait = 0;
			Character_StopMoving(this);
			if ((flags & CHF_MOVENOTWALK) == 0) {
				// use standing pic
				chex->animwait = 0;
				frame = 0;
				chex->CheckViewFrame(this);
			}
		} else if (chex->animwait > 0) {
			chex->animwait--;
		} else {
			if (flags & CHF_ANTIGLIDE)
				walkwaitcounter++;

			if ((flags & CHF_MOVENOTWALK) == 0) {
				frame++;
				if (frame >= _GP(views)[view].loops[loop].numFrames) {
					// end of loop, so loop back round skipping the standing frame
					frame = 1;

					if (_GP(views)[view].loops[loop].numFrames < 2)
						frame = 0;
				}

				chex->animwait = _GP(views)[view].loops[loop].frames[frame].speed + animspeed;

				if (flags & CHF_ANTIGLIDE)
					walkwait = chex->animwait;
				else
					walkwait = 0;

				chex->CheckViewFrame(this);
			}
		}
	}
}

int CharacterInfo::update_character_animating(int &aa, int &doing_nothing) {
	CharacterExtras *chex = &_GP(charextra)[index_id];

	// not moving, but animating
	// idleleft is <0 while idle view is playing (.animating is 0)
	if (((animating != 0) || (idleleft < 0)) &&
	        ((walking == 0) || ((flags & CHF_MOVENOTWALK) != 0)) &&
	        (room == _G(displayed_room))) {
		doing_nothing = 0;
		// idle anim doesn't count as doing something
		if (idleleft < 0)
			doing_nothing = 1;

		if (wait > 0) wait--;
		else if ((_G(char_speaking) == aa) && (_GP(game).options[OPT_LIPSYNCTEXT] != 0)) {
			// currently talking with lip-sync speech
			int fraa = frame;
			wait = update_lip_sync(view, loop, &fraa) - 1;
			// closed mouth at end of sentence
			// NOTE: standard lip-sync is synchronized with text timer, not voice file
			if (_GP(play).speech_in_post_state ||
			        ((_GP(play).messagetime >= 0) && (_GP(play).messagetime < _GP(play).close_mouth_speech_time)))
				frame = 0;

			if (frame != fraa) {
				frame = fraa;
				chex->CheckViewFrame(this);
			}

			//continue;
			return RETURN_CONTINUE;
		} else {
			// Normal view animation
			const int oldframe = frame;

			bool done_anim = false;
			if ((aa == _G(char_speaking)) &&
				(_GP(play).speech_in_post_state ||
				((!_GP(play).speech_has_voice) &&
					(_GP(play).close_mouth_speech_time > 0) &&
					(_GP(play).messagetime < _GP(play).close_mouth_speech_time)))) {
				// finished talking - stop animation
				done_anim = true;
				frame = 0;
			} else {
				if (!CycleViewAnim(view, loop, frame, get_anim_forwards(), get_anim_repeat())) {
					done_anim = true; // finished animating
					// end of idle anim
					if (idleleft < 0) {
						// constant anim, reset (need this cos animating==0)
						if (idletime == 0)
							frame = 0;
						// one-off anim, stop
						else {
							ReleaseCharacterView(aa);
							idleleft = idletime;
						}
					}
				}
			}

			wait = _GP(views)[view].loops[loop].frames[frame].speed;
			// idle anim doesn't have speed stored cos animating==0 (TODO: investigate why?)
			if (idleleft < 0)
				wait += idle_anim_speed;
			else
				wait += get_anim_delay();

			if (frame != oldframe)
				chex->CheckViewFrame(this);

			if (done_anim)
				stop_character_anim(this);
		}
	}

	return 0;
}

void CharacterInfo::update_character_follower(int &aa, std::vector<int> &followingAsSheep, int &doing_nothing) {
	if ((following >= 0) && (followinfo == FOLLOW_ALWAYSONTOP)) {
		// an always-on-top follow
		followingAsSheep.push_back(aa);
	}

	// not moving, but should be following another character
	else if ((following >= 0) && (doing_nothing == 1)) {
		short distaway = (followinfo >> 8) & 0x00ff;
		// no character in this room
		if ((_GP(game).chars[following].on == 0) || (on == 0));
		else if (room < 0) {
			room++;
			if (room == 0) {
				// appear in the new room
				room = _GP(game).chars[following].room;
				x = _GP(play).entered_at_x;
				y = _GP(play).entered_at_y;
			}
		}
		// wait a bit, so we're not constantly walking
		else if (Random(100) < (followinfo & 0x00ff));
		// the followed character has changed room
		else if ((room != _GP(game).chars[following].room)
		         && (_GP(game).chars[following].on == 0))
			;  // do nothing if the player isn't visible
		else if (room != _GP(game).chars[following].room) {
			prevroom = room;
			room = _GP(game).chars[following].room;

			if (room == _G(displayed_room)) {
				// only move to the room-entered position if coming into
				// the current room
				if (_GP(play).entered_at_x > (_GP(thisroom).Width - 8)) {
					x = _GP(thisroom).Width + 8;
					y = _GP(play).entered_at_y;
				} else if (_GP(play).entered_at_x < 8) {
					x = -8;
					y = _GP(play).entered_at_y;
				} else if (_GP(play).entered_at_y > (_GP(thisroom).Height - 8)) {
					y = _GP(thisroom).Height + 8;
					x = _GP(play).entered_at_x;
				} else if (_GP(play).entered_at_y < _GP(thisroom).Edges.Top + 8) {
					y = _GP(thisroom).Edges.Top + 1;
					x = _GP(play).entered_at_x;
				} else {
					// not at one of the edges
					// delay for a few seconds to let the player move
					room = -_GP(play).follow_change_room_timer;
				}
				if (room >= 0) {
					walk_character(aa, _GP(play).entered_at_x, _GP(play).entered_at_y, 1, true);
					doing_nothing = 0;
				}
			}
		} else if (room != _G(displayed_room)) {
			// if the character is following another character and
			// neither is in the current room, don't try to move
		} else if ((abs(_GP(game).chars[following].x - x) > distaway + 30) ||
		           (abs(_GP(game).chars[following].y - y) > distaway + 30) ||
		           ((followinfo & 0x00ff) == 0)) {
			// in same room
			int goxoffs = (Random(50) - 25);
			// make sure he's not standing on top of the other man
			if (goxoffs < 0) goxoffs -= distaway;
			else goxoffs += distaway;
			walk_character(aa, _GP(game).chars[following].x + goxoffs,
			               _GP(game).chars[following].y + (Random(50) - 25), 0, true);
			doing_nothing = 0;
		}
	}
}

void CharacterInfo::update_character_idle(CharacterExtras *chex, int &doing_nothing) {
	// no idle animation, so skip this bit
	if (idleview < 1);
	// currently playing idle anim
	else if (idleleft < 0);
	// not in the current room
	else if (room != _G(displayed_room));
	// they are moving or animating (or the view is locked), so
	// reset idle timeout
	else if ((doing_nothing == 0) || ((flags & CHF_FIXVIEW) != 0))
		idleleft = idletime;
	// count idle time
	else if ((_G(loopcounter) % GetGameSpeed() == 0) || (chex->process_idle_this_time == 1)) {
		idleleft--;
		if (idleleft == -1) {
			int useloop = loop;
			debug_script_log("%s: Now idle (view %d)", scrname, idleview + 1);
			Character_LockView(this, idleview + 1);
			// SetCharView resets it to 0
			idleleft = -2;
			int maxLoops = _GP(views)[idleview].numLoops;
			// if the char is set to "no diagonal loops", don't try
			// to use diagonal idle loops either
			if ((maxLoops > 4) && (useDiagonal(this)))
				maxLoops = 4;
			// If it's not a "swimming"-type idleanim, choose a random loop
			// if there arent enough loops to do the current one.
			if ((idletime > 0) && (useloop >= maxLoops)) {
				do {
					useloop = ::AGS::g_vm->getRandomNumber(maxLoops - 1);
					// don't select a loop which is a continuation of a previous one
				} while ((useloop > 0) && (_GP(views)[idleview].loops[useloop - 1].RunNextLoop()));
			}
			// Normal idle anim - just reset to loop 0 if not enough to
			// use the current one
			else if (useloop >= maxLoops)
				useloop = 0;

			animate_character(this, useloop, idle_anim_speed, (idletime == 0) ? 1 : 0 /* repeat */);

			// don't set Animating while the idle anim plays (TODO: investigate why?)
			animating = 0;
		}
	}  // end do idle animation
}

} // namespace AGS3