/*
 * This software is licensed under the terms of the MIT License.
 * See COPYING for further information.
 * ---
 * Copyright (c) 2011-2019, Lukas Weber <laochailan@web.de>.
 * Copyright (c) 2012-2019, Andrei Alexeyev <akari@taisei-project.org>.
 */

#include "taisei.h"

#include "common.h"
#include "global.h"
#include "menu.h"
#include "savereplay.h"
#include "difficultyselect.h"
#include "cutscenes/cutscene.h"
#include "charselect.h"
#include "credits.h"
#include "mainmenu.h"
#include "progress.h"
#include "video.h"
#include "replay/struct.h"
#include "replay/state.h"
#include "util/graphics.h"
#include "stage.h"

typedef struct StartGameContext {
	StageInfo *restart_stage;
	StageInfo *current_stage;
	MenuData *diff_menu;
	MenuData *char_menu;
	Replay replay;
	Difficulty difficulty;
	ResourceGroup rg;
} StartGameContext;

static void start_game_do_pick_character(CallChainResult ccr);
static void start_game_do_enter_stage(CallChainResult ccr);
static void start_game_do_leave_stage(CallChainResult ccr);
static void start_game_do_show_ending(CallChainResult ccr);
static void start_game_do_show_credits(CallChainResult ccr);
static void start_game_do_cleanup(CallChainResult ccr);

static void start_game_internal(MenuData *menu, StageInfo *info, bool difficulty_menu) {
	auto ctx = ALLOC(StartGameContext);
	res_group_init(&ctx->rg);

	if(info == NULL) {
		global.is_practice_mode = false;
		ctx->current_stage = ctx->restart_stage = stageinfo_get_by_id(1);
	} else {
		global.is_practice_mode = (info->type != STAGE_EXTRA);
		ctx->current_stage = info;
		ctx->restart_stage = info;
	}

	Difficulty stagediff = info ? info->difficulty : D_Any;

	CallChain cc_pick_character = CALLCHAIN(start_game_do_pick_character, ctx);

	if(stagediff == D_Any) {
		if(difficulty_menu) {
			ctx->diff_menu = create_difficulty_menu();
			enter_menu(ctx->diff_menu, cc_pick_character);
		} else {
			ctx->difficulty = progress.game_settings.difficulty;
			run_call_chain(&cc_pick_character, NULL);
		}
	} else {
		ctx->difficulty = stagediff;
		run_call_chain(&cc_pick_character, NULL);
	}
}

static void start_game_do_pick_character(CallChainResult ccr) {
	StartGameContext *ctx = ccr.ctx;
	MenuData *prev_menu = ccr.result;

	if(prev_menu) {
		if(prev_menu->state == MS_Dead) {
			start_game_do_cleanup(ccr);
			return;
		}

		// came here from the difficulty menu - update our setting
		ctx->difficulty = progress.game_settings.difficulty;
	}

	assert(ctx->char_menu == NULL);
	ctx->char_menu = create_char_menu();
	enter_menu(ctx->char_menu, CALLCHAIN(start_game_do_enter_stage, ctx));
}

static void reset_game(StartGameContext *ctx) {
	ctx->current_stage = ctx->restart_stage;

	global.gameover = GAMEOVER_NONE;
	replay_reset(&ctx->replay);
	replay_state_init_record(&global.replay.output, &ctx->replay);
	player_init(&global.plr);
	stats_init(&global.plr.stats);
	global.plr.mode = plrmode_find(
		progress.game_settings.character,
		progress.game_settings.shotmode
	);
	global.diff = ctx->difficulty;

	assert(global.plr.mode != NULL);
}

static void kill_aux_menus(StartGameContext *ctx) {
	kill_menu(ctx->char_menu);
	kill_menu(ctx->diff_menu);
	ctx->char_menu = ctx->diff_menu = NULL;
}

static void enter_stage_now(StartGameContext *ctx) {
	res_group_release(&ctx->rg);
	stage_enter(ctx->current_stage, &ctx->rg, CALLCHAIN(start_game_do_leave_stage, ctx));
}

static void start_game_do_enter_stage(CallChainResult ccr) {
	StartGameContext *ctx = ccr.ctx;
	MenuData *prev_menu = ccr.result;

	if(prev_menu && prev_menu->state == MS_Dead) {
		assert(prev_menu == ctx->char_menu);
		ctx->char_menu = NULL;

		if(!ctx->diff_menu) {
			start_game_do_cleanup(ccr);
		}

		return;
	}

	kill_aux_menus(ctx);
	reset_game(ctx);
	enter_stage_now(ctx);
}

static void start_game_do_leave_stage(CallChainResult ccr) {
	StartGameContext *ctx = ccr.ctx;

	if(global.gameover == GAMEOVER_RESTART) {
		reset_game(ctx);
		enter_stage_now(ctx);
		return;
	}

	if(ctx->current_stage->type == STAGE_STORY && !global.is_practice_mode) {
		++ctx->current_stage;

		if(ctx->current_stage->type == STAGE_STORY) {
			enter_stage_now(ctx);
		} else {
			CallChain cc;

			if(global.gameover == GAMEOVER_WIN) {
				res_group_release(&ctx->rg);
				res_purge();
				credits_preload(&ctx->rg);
				cc = CALLCHAIN(start_game_do_show_ending, ctx);
			} else {
				cc = CALLCHAIN(start_game_do_cleanup, ctx);
			}

			ask_save_replay(&ctx->replay, cc);
		}
	} else {
		ask_save_replay(&ctx->replay, CALLCHAIN(start_game_do_cleanup, ctx));
	}
}

static void start_game_do_show_ending(CallChainResult ccr) {
	Player *plr = &global.plr;
	PlayerCharacter *character = plr->mode->character;
	PlrCharEndingCutscene *ec_id;

	if (plr->stats.total.continues_used) {
		ec_id = &character->ending.bad;
	} else {
		ec_id = &character->ending.good;
	}

	progress_track_ending(ec_id->ending_id);
	cutscene_enter(CALLCHAIN(start_game_do_show_credits, ccr.ctx), ec_id->cutscene_id);
}

static void start_game_do_show_credits(CallChainResult ccr) {
	credits_enter(CALLCHAIN(start_game_do_cleanup, ccr.ctx));
}

static void start_game_do_cleanup(CallChainResult ccr) {
	StartGameContext *ctx = ccr.ctx;
	replay_reset(&ctx->replay);
	kill_aux_menus(ctx);
	res_group_release(&ctx->rg);
	mem_free(ctx);
	global.gameover = GAMEOVER_NONE;
	replay_state_deinit(&global.replay.output);
	main_menu_update_practice_menus();
	audio_bgm_play(res_bgm("menu"), true, 0, 0);
}

void start_game(MenuData *m, void *arg) {
	start_game_internal(m, (StageInfo*)arg, true);
}

void start_game_no_difficulty_menu(MenuData *m, void *arg) {
	start_game_internal(m, (StageInfo*)arg, false);
}

void draw_menu_selector(float x, float y, float w, float h, float t) {
	Sprite *bg = res_sprite("part/smoke");
	r_mat_mv_push();
	r_mat_mv_translate(x, y, 0);
	r_mat_mv_scale(w / bg->w, h / bg->h, 1);
	r_mat_mv_rotate(t * 2 * DEG2RAD, 0, 0, 1);
	r_draw_sprite(&(SpriteParams) {
		.sprite_ptr = bg,
		.color = RGBA(0, 0, 0, 0.5 * (1 - transition.fade)),
		.shader = "sprite_default",
	});
	r_mat_mv_pop();
}

void draw_menu_title(MenuData *m, const char *title) {
	text_draw(title, &(TextParams) {
		.pos = { (text_width(res_font("big"), title, 0) + 10) * (1.0 - menu_fade(m)), 30 },
		.align = ALIGN_RIGHT,
		.font = "big",
		.color = RGB(1, 1, 1),
		.shader = "text_default",
	});
}

void draw_menu_list(MenuData *m, float x, float y, void (*draw)(MenuEntry*, int, int, void*), float scroll_threshold, void *userdata) {
	r_mat_mv_push();
	float offset = smoothmin(0, scroll_threshold * 0.8 - y - m->drawdata[2], 80);
	r_mat_mv_translate(x, y + offset, 0);

	draw_menu_selector(m->drawdata[0], m->drawdata[2], m->drawdata[1], 34, m->frames);
	ShaderProgram *text_shader = res_shader("text_default");

	dynarray_foreach(&m->entries, int i, MenuEntry *e, {
		float p = offset + 20*i;

		if(p < -y-10 || p > SCREEN_H+10)
			continue;

		float a = e->drawdata * 0.1;
		float o = (p < 0? 1-p/(-y-10) : 1);

		Color clr;

		if(e->action == NULL) {
			clr = *RGBA_MUL_ALPHA(0.5, 0.5, 0.5, 0.5*o);
		} else {
			float ia = 1-a;
			clr = *RGBA_MUL_ALPHA(0.9 + ia * 0.1, 0.6 + ia * 0.4, 0.2 + ia * 0.8, (0.7 + 0.3 * a)*o);
		}

		r_color(&clr);

		if(draw && i < m->entries.num_elements-1) {
			draw(e, i, m->entries.num_elements, userdata);
		} else if(e->name) {
			text_draw(e->name, &(TextParams) {
				.pos = { 20 - e->drawdata, 20*i },
				.shader_ptr = text_shader,
			});
		}
	});

	r_mat_mv_pop();
}

void animate_menu_list_entry(MenuData *m, int i) {
	MenuEntry *e = dynarray_get_ptr(&m->entries, i);
	fapproach_asymptotic_p(&e->drawdata, 10 * (i == m->cursor), 0.2, 1e-4);
}

void animate_menu_list_entries(MenuData *m) {
	dynarray_foreach_idx(&m->entries, int i, {
		animate_menu_list_entry(m, i);
	});
}

void animate_menu_list(MenuData *m) {
	MenuEntry *s = dynarray_get_ptr(&m->entries, m->cursor);
	int w = text_width(res_font("standard"), s->name, 0);

	fapproach_asymptotic_p(&m->drawdata[0], 10 + w * 0.5, 0.1, 1e-5);
	fapproach_asymptotic_p(&m->drawdata[1], w * 2, 0.1, 1e-5);
	fapproach_asymptotic_p(&m->drawdata[2], 20 * m->cursor, 0.1, 1e-5);

	animate_menu_list_entries(m);
}

void menu_action_close(MenuData *menu, void *arg) {
	menu->state = MS_Dead;
}
