/*
   Copyright (C) 2014 - 2018 by Chris Beck <render787@gmail.com>
   Part of the Battle for Wesnoth Project https://www.wesnoth.org/

   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 2 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.

   See the COPYING file for more details.
*/

#include "units/drawer.hpp"

#include "display.hpp"
#include "display_context.hpp"
#include "formatter.hpp"
#include "game_display.hpp"
#include "preferences/game.hpp"
#include "halo.hpp"
#include "map/map.hpp"
#include "map/location.hpp"
#include "color.hpp"
#include "sdl/surface.hpp"
#include "team.hpp"
#include "units/unit.hpp"
#include "units/animation.hpp"
#include "units/animation_component.hpp"
#include "units/frame.hpp"

// Map of different energy bar surfaces and their dimensions.
static std::map<surface, SDL_Rect> energy_bar_rects;

unit_drawer::unit_drawer(display & thedisp) :
	disp(thedisp),
	dc(disp.get_disp_context()),
	map(dc.map()),
	teams(dc.teams()),
	halo_man(thedisp.get_halo_manager()),
	viewing_team(disp.viewing_team()),
	playing_team(disp.playing_team()),
	viewing_team_ref(teams[viewing_team]),
	playing_team_ref(teams[playing_team]),
	is_blindfolded(disp.is_blindfolded()),
	show_everything(disp.show_everything()),
	sel_hex(disp.selected_hex()),
	mouse_hex(disp.mouseover_hex()),
	zoom_factor(disp.get_zoom_factor()),
	hex_size(disp.hex_size()),
	hex_size_by_2(disp.hex_size()/2)
{
	if(const game_display* game_display = dynamic_cast<class game_display*>(&disp)) {
		units_that_can_reach_goal = game_display->units_that_can_reach_goal();
	}
}

void unit_drawer::redraw_unit (const unit & u) const
{
	unit_animation_component & ac = u.anim_comp();
	map_location loc = u.get_location();

	int side = u.side();

	bool hidden = u.get_hidden();
	bool is_flying = u.is_flying();
	map_location::DIRECTION facing = u.facing();
	int hitpoints = u.hitpoints();
	int max_hitpoints = u.max_hitpoints();
	int movement_left = u.movement_left();
	int total_movement = u.total_movement();

	bool can_recruit = u.can_recruit();
	bool can_advance = u.can_advance();

	int experience = u.experience();
	int max_experience = u.max_experience();

	bool emit_zoc = u.emits_zoc();

	color_t hp_color=u.hp_color();
	color_t xp_color=u.xp_color();

	std::string ellipse=u.image_ellipse();

	const bool is_highlighted_enemy = units_that_can_reach_goal.count(loc) > 0;
	const bool is_selected_hex = (loc == sel_hex || is_highlighted_enemy);

	if(hidden || is_blindfolded || !u.is_visible_to_team(viewing_team_ref, show_everything)) {
		ac.clear_haloes();
		if(ac.anim_) {
			ac.anim_->update_last_draw_time();
		}
		return;
	}

	if (!ac.anim_) {
		ac.set_standing();
		if (!ac.anim_) return;
	}

	if (ac.refreshing_) return;
	ac.refreshing_ = true;

	ac.anim_->update_last_draw_time();
	frame_parameters params;
	const t_translation::terrain_code terrain = map.get_terrain(loc);
	const terrain_type& terrain_info = map.get_terrain_info(terrain);

	// do not set to 0 so we can distinguish the flying from the "not on submerge terrain"
	// instead use -1.0 (as in "negative depth", it will be ignored by rendering)
	params.submerge= is_flying ? -1.0 : terrain_info.unit_submerge();

	if(u.invisible(loc) && params.highlight_ratio > 0.6) {
		params.highlight_ratio = 0.6;
	}
	if (is_selected_hex && params.highlight_ratio == 1.0) {
		params.highlight_ratio = 1.5;
	}

	int height_adjust = static_cast<int>(terrain_info.unit_height_adjust() * zoom_factor);
	if (is_flying && height_adjust < 0) {
		height_adjust = 0;
	}
	params.y -= height_adjust;
	params.halo_y -= height_adjust;

	int red = 0,green = 0,blue = 0,tints = 0;
	double blend_ratio = 0;
	// Add future colored states here
	if(u.poisoned()) {
		green += 255;
		blend_ratio += 0.25;
		tints += 1;
	}
	if(u.slowed()) {
		red += 191;
		green += 191;
		blue += 255;
		blend_ratio += 0.25;
		tints += 1;
	}
	if(tints > 0) {
		params.blend_with = color_t((red/tints),(green/tints),(blue/tints));
		params.blend_ratio = ((blend_ratio/tints));
	}

	//hackish : see unit_frame::merge_parameters
	// we use image_mod on the primary image
	// and halo_mod on secondary images and all haloes
	params.image_mod = u.image_mods();
	params.halo_mod = u.TC_image_mods();
	params.image= u.default_anim_image();


	if(u.incapacitated()) params.image_mod +="~GS()";
	params.primary_frame = true;


	const frame_parameters adjusted_params = ac.anim_->get_current_params(params);

	const map_location dst = loc.get_direction(facing);
	const int xsrc = disp.get_location_x(loc);
	const int ysrc = disp.get_location_y(loc);
	const int xdst = disp.get_location_x(dst);
	const int ydst = disp.get_location_y(dst);

	const int x = static_cast<int>(adjusted_params.offset * xdst + (1.0-adjusted_params.offset) * xsrc) + hex_size_by_2;
	const int y = static_cast<int>(adjusted_params.offset * ydst + (1.0-adjusted_params.offset) * ysrc) + hex_size_by_2;

	bool has_halo = ac.unit_halo_ && ac.unit_halo_->valid();
	if(!has_halo && !u.image_halo().empty()) {
		ac.unit_halo_ = halo_man.add(x, y - height_adjust, u.image_halo()+u.TC_image_mods(), map_location(-1, -1));
	}
	if(has_halo && u.image_halo().empty()) {
		halo_man.remove(ac.unit_halo_);
		ac.unit_halo_.reset();
	} else if(has_halo) {
		halo_man.set_location(ac.unit_halo_, x, y - height_adjust);
	}

	// We draw bars only if wanted, visible on the map view
	bool draw_bars = ac.draw_bars_ ;
	if (draw_bars) {
		SDL_Rect unit_rect {xsrc, ysrc +adjusted_params.y, hex_size, hex_size};
		draw_bars = sdl::rects_overlap(unit_rect, disp.map_outside_area());
	}
	surface ellipse_front(nullptr);
	surface ellipse_back(nullptr);
	int ellipse_floating = 0;
	// Always show the ellipse for selected units
	if(draw_bars && (preferences::show_side_colors() || is_selected_hex)) {
		if(adjusted_params.submerge > 0.0) {
			// The division by 2 seems to have no real meaning,
			// It just works fine with the current center of ellipse
			// and prevent a too large adjust if submerge = 1.0
			ellipse_floating = static_cast<int>(adjusted_params.submerge * hex_size_by_2);
		}

		if(ellipse.empty()){
			ellipse="misc/ellipse";
		}

		if(ellipse != "none") {
			// check if the unit has a ZoC or can recruit
			const std::string nozoc    = !emit_zoc      ? "nozoc-"    : "";
			const std::string leader   = can_recruit    ? "leader-"   : "";
			const std::string selected = is_selected_hex? "selected-" : "";
			const std::string tc       = team::get_side_color_id(side);

			const std::string ellipse_top = formatter() << ellipse << "-" << leader << nozoc << selected << "top.png~RC(ellipse_red>" << tc << ")";
			const std::string ellipse_bot = formatter() << ellipse << "-" << leader << nozoc << selected << "bottom.png~RC(ellipse_red>" << tc << ")";

			// Load the ellipse parts recolored to match team color
			ellipse_back = image::get_image(image::locator(ellipse_top), image::SCALED_TO_ZOOM);
			ellipse_front = image::get_image(image::locator(ellipse_bot), image::SCALED_TO_ZOOM);
		}
	}
	if (ellipse_back != nullptr) {
		//disp.drawing_buffer_add(display::LAYER_UNIT_BG, loc,
		disp.drawing_buffer_add(display::LAYER_UNIT_FIRST, loc,
			xsrc, ysrc +adjusted_params.y-ellipse_floating, ellipse_back);
	}

	if (ellipse_front != nullptr) {
		//disp.drawing_buffer_add(display::LAYER_UNIT_FG, loc,
		disp.drawing_buffer_add(display::LAYER_UNIT_FIRST, loc,
			xsrc, ysrc +adjusted_params.y-ellipse_floating, ellipse_front);
	}
	if(draw_bars) {
		const image::locator* orb_img = nullptr;

		const auto& type_cfg = u.type().get_cfg();
		const auto& cfg_offset_x = type_cfg["bar_offset_x"];
		const auto& cfg_offset_y = type_cfg["bar_offset_y"];
		int xoff;
		int yoff;
		if(cfg_offset_x.empty() && cfg_offset_y.empty()) {
			const surface unit_img = image::get_image(u.default_anim_image(), image::SCALED_TO_ZOOM);
			xoff = !unit_img ? 0 : (hex_size - unit_img->w)/2;
			yoff = !unit_img ? 0 : (hex_size - unit_img->h)/2;
		}
		else {
			xoff = cfg_offset_x.to_int();
			yoff = cfg_offset_y.to_int();
		}

		/*static*/ const image::locator partmoved_orb(game_config::images::orb + "~RC(magenta>" +
						preferences::partial_color() + ")"  );
		/*static*/ const image::locator moved_orb(game_config::images::orb + "~RC(magenta>" +
						preferences::moved_color() + ")"  );
		/*static*/ const image::locator ally_orb(game_config::images::orb + "~RC(magenta>" +
						preferences::allied_color() + ")"  );
		/*static*/ const image::locator enemy_orb(game_config::images::orb + "~RC(magenta>" +
						preferences::enemy_color() + ")"  );
		/*static*/ const image::locator unmoved_orb(game_config::images::orb + "~RC(magenta>" +
						preferences::unmoved_color() + ")"  );

		const std::string* energy_file = &game_config::images::energy;

		if(std::size_t(side) != viewing_team+1) {
			if(disp.team_valid() &&
			   viewing_team_ref.is_enemy(side)) {
				if (preferences::show_enemy_orb() && !u.incapacitated())
					orb_img = &enemy_orb;
				else
					orb_img = nullptr;
			} else {
				if (preferences::show_allied_orb())
					orb_img = &ally_orb;
				else orb_img = nullptr;
			}
		} else {
			if (preferences::show_moved_orb())
				orb_img = &moved_orb;
			else orb_img = nullptr;

			if(playing_team == viewing_team && !u.user_end_turn()) {
				if (movement_left == total_movement) {
					if (preferences::show_unmoved_orb())
						orb_img = &unmoved_orb;
					else orb_img = nullptr;
				} else if ( dc.unit_can_move(u) ) {
					if (preferences::show_partial_orb())
						orb_img = &partmoved_orb;
					else orb_img = nullptr;
				}
			}
		}

		if (orb_img != nullptr) {
			surface orb(image::get_image(*orb_img,image::SCALED_TO_ZOOM));
			disp.drawing_buffer_add(display::LAYER_UNIT_BAR,
				loc, xsrc + xoff, ysrc + yoff + adjusted_params.y, orb);
		}

		double unit_energy = 0.0;
		if(max_hitpoints > 0) {
			unit_energy = static_cast<double>(hitpoints)/static_cast<double>(max_hitpoints);
		}
		const int bar_shift = static_cast<int>(-5*zoom_factor);
		const int hp_bar_height = static_cast<int>(max_hitpoints * u.hp_bar_scaling());

		const fixed_t bar_alpha = (loc == mouse_hex || is_selected_hex) ? ftofxp(1.0): ftofxp(0.8);

		draw_bar(*energy_file, xsrc+xoff+bar_shift, ysrc+yoff+adjusted_params.y,
			loc, hp_bar_height, unit_energy,hp_color, bar_alpha);

		if(experience > 0 && can_advance) {
			const double filled = static_cast<double>(experience) / static_cast<double>(max_experience);
			const int xp_bar_height = static_cast<int>(max_experience * u.xp_bar_scaling() / std::max<int>(u.level(),1));

			draw_bar(*energy_file, xsrc+xoff, ysrc+yoff+adjusted_params.y,
				loc, xp_bar_height, filled, xp_color, bar_alpha);
		}

		if (can_recruit) {
			surface crown(image::get_image(u.leader_crown(),image::SCALED_TO_ZOOM));
			if(crown) {
				//if(bar_alpha != ftofxp(1.0)) {
				//	crown = adjust_surface_alpha(crown, bar_alpha);
				//}
				disp.drawing_buffer_add(display::LAYER_UNIT_BAR,
					loc, xsrc+xoff, ysrc+yoff+adjusted_params.y, crown);
			}
		}

		for(const std::string& ov : u.overlays()) {
			const surface ov_img(image::get_image(ov, image::SCALED_TO_ZOOM));
			if(ov_img != nullptr) {
				disp.drawing_buffer_add(display::LAYER_UNIT_BAR,
					loc, xsrc+xoff, ysrc+yoff+adjusted_params.y, ov_img);
			}
		}
	}

	// Smooth unit movements from terrain of different elevation.
	// Do this separately from above so that the health bar doesn't go up and down.

	const t_translation::terrain_code terrain_dst = map.get_terrain(dst);
	const terrain_type& terrain_dst_info = map.get_terrain_info(terrain_dst);

	int height_adjust_unit = static_cast<int>((terrain_info.unit_height_adjust() * (1.0 - adjusted_params.offset) +
											  terrain_dst_info.unit_height_adjust() * adjusted_params.offset) *
											  zoom_factor);
	if (is_flying && height_adjust_unit < 0) {
		height_adjust_unit = 0;
	}
	params.y -= height_adjust_unit - height_adjust;
	params.halo_y -= height_adjust_unit - height_adjust;

	ac.anim_->redraw(params, halo_man);
	ac.refreshing_ = false;
}

void unit_drawer::draw_bar(const std::string& image, int xpos, int ypos,
		const map_location& loc, std::size_t height, double filled,
		const color_t& col, fixed_t alpha) const
{

	filled = std::min<double>(std::max<double>(filled,0.0),1.0);
	height = static_cast<std::size_t>(height*zoom_factor);

	surface surf(image::get_image(image,image::SCALED_TO_HEX));

	// We use UNSCALED because scaling (and bilinear interpolation)
	// is bad for calculate_energy_bar.
	// But we will do a geometric scaling later.
	surface bar_surf(image::get_image(image));
	if(surf == nullptr || bar_surf == nullptr) {
		return;
	}

	// calculate_energy_bar returns incorrect results if the surface colors
	// have changed (for example, due to bilinear interpolation)
	const SDL_Rect& unscaled_bar_loc = calculate_energy_bar(bar_surf);

	SDL_Rect bar_loc;
	if (surf->w == bar_surf->w && surf->h == bar_surf->h)
		bar_loc = unscaled_bar_loc;
	else {
		const fixed_t xratio = fxpdiv(surf->w,bar_surf->w);
		const fixed_t yratio = fxpdiv(surf->h,bar_surf->h);
		const SDL_Rect scaled_bar_loc {
			    fxptoi(unscaled_bar_loc. x * xratio)
			  , fxptoi(unscaled_bar_loc. y * yratio + 127)
			  , fxptoi(unscaled_bar_loc. w * xratio + 255)
			  , fxptoi(unscaled_bar_loc. h * yratio + 255)
		};
		bar_loc = scaled_bar_loc;
	}

	if(height > static_cast<std::size_t>(bar_loc.h)) {
		height = bar_loc.h;
	}

	//if(alpha != ftofxp(1.0)) {
	//	surf.assign(adjust_surface_alpha(surf,alpha));
	//	if(surf == nullptr) {
	//		return;
	//	}
	//}

	const std::size_t skip_rows = bar_loc.h - height;

	SDL_Rect top {0, 0, surf->w, bar_loc.y};
	SDL_Rect bot = sdl::create_rect(0, bar_loc.y + skip_rows, surf->w, 0);
	bot.h = surf->w - bot.y;

	disp.drawing_buffer_add(display::LAYER_UNIT_BAR, loc, xpos, ypos, surf, top);
	disp.drawing_buffer_add(display::LAYER_UNIT_BAR, loc, xpos, ypos + top.h, surf, bot);

	std::size_t unfilled = static_cast<std::size_t>(height * (1.0 - filled));

	if(unfilled < height && alpha >= ftofxp(0.3)) {
		const uint8_t r_alpha = std::min<unsigned>(unsigned(fxpmult(alpha,255)),255);
		surface filled_surf(bar_loc.w, height - unfilled);
		SDL_Rect filled_area = sdl::create_rect(0, 0, bar_loc.w, height-unfilled);
		sdl::fill_surface_rect(filled_surf,&filled_area,SDL_MapRGBA(bar_surf->format,col.r,col.g,col.b, r_alpha));
		disp.drawing_buffer_add(display::LAYER_UNIT_BAR, loc, xpos + bar_loc.x, ypos + bar_loc.y + unfilled, filled_surf);
	}
}

struct is_energy_color {
	bool operator()(uint32_t color) const { return (color&0xFF000000) > 0x10000000 &&
	                                              (color&0x00FF0000) < 0x00100000 &&
												  (color&0x0000FF00) < 0x00001000 &&
												  (color&0x000000FF) < 0x00000010; }
};

const SDL_Rect& unit_drawer::calculate_energy_bar(surface surf) const
{
	const std::map<surface,SDL_Rect>::const_iterator i = energy_bar_rects.find(surf);
	if(i != energy_bar_rects.end()) {
		return i->second;
	}

	int first_row = -1, last_row = -1, first_col = -1, last_col = -1;

	const_surface_lock image_lock(surf);
	const uint32_t* const begin = image_lock.pixels();

	for(int y = 0; y != surf->h; ++y) {
		const uint32_t* const i1 = begin + surf->w*y;
		const uint32_t* const i2 = i1 + surf->w;
		const uint32_t* const itor = std::find_if(i1,i2,is_energy_color());
		const int count = std::count_if(itor,i2,is_energy_color());

		if(itor != i2) {
			if(first_row == -1) {
				first_row = y;
			}

			first_col = itor - i1;
			last_col = first_col + count;
			last_row = y;
		}
	}

	const SDL_Rect res {
			  first_col
			, first_row
			, last_col-first_col
			, last_row+1-first_row
	};
	energy_bar_rects.emplace(surf, res);
	return calculate_energy_bar(surf);
}