package main

import "core:fmt"
import "core:math"
import "core:math/ease"
import rl "vendor:raylib"

SFX: []u8 : #load("sfx.mp3")
OTF: []u8 : #load("a.otf")

color_mul_rgb :: proc(a, b: rl.Color) -> rl.Color {
	return {
		u8((f32(a.r) * f32(b.r)) / 255),
		u8((f32(a.g) * f32(b.g)) / 255),
		u8((f32(a.b) * f32(b.b)) / 255),
		255,
	}
}

with_alpha :: proc(c: rl.Color, alpha: f32) -> rl.Color {
	out := c
	out.a = u8(clamp(alpha, 0, 1) * 255)
	return out
}

ease_out_back :: proc(t: f32, s: f32 = 1.70158) -> f32 {
	t1 := clamp(t, 0, 1)
	return 1 + s * math.pow(t1 - 1, 3) + s * (t1 - 1) * math.pow(t1 - 1, 2)
}

adsr :: proc(t, attack, decay, sustain: f32, r_start: f32, r_dur: f32) -> f32 {
	if t <= 0 {return 0}
	if t < attack {
		return ease.cubic_out(t / attack)
	}
	if t < attack + decay {
		return f32(math.lerp(f32(1), sustain, ease.cubic_in_out((t - attack) / decay)))
	}
	if t < r_start {
		return sustain
	}
	return sustain * (1 - ease.cubic_out((t - r_start) / math.max(r_dur, 0.0001)))
}

draw_noun_verbed_sheen :: proc(
	font: rl.Font,
	text: string,
	center: rl.Vector2,
	base_font_size: f32,
	spacing: f32,
	text_color: rl.Color,
	text_opacity: f32,
	sheen_tint: rl.Color,
	blur_size_: f32,
	blur_opacity: f32,
) {
	blur_size := blur_size_
	screen_h := rl.GetScreenHeight()
	s := f32(screen_h) / 1080.0

	if blur_size <= 1.0001 {
		blur_size = 1.0001
	}

	steps_f := 20.0 * blur_size * math.pow(s, 0.25)
	zoomSteps := i32(math.floor(steps_f))
	if zoomSteps < 6 {
		zoomSteps = 6
	}

	voff := s / (blur_size - 1.0)

	base_size := rl.MeasureTextEx(font, fmt.ctprintf("{}", text), base_font_size, spacing)
	base_origin := rl.Vector2{base_size.x * 0.5, base_size.y * 0.5}

	glow_base := color_mul_rgb(text_color, sheen_tint)

	rl.BeginBlendMode(.ADDITIVE)
	for i := zoomSteps; i >= 0; i -= 1 {
		t := f32(i) / f32(zoomSteps)
		scale_factor := f32(math.pow(blur_size, t))

		denom := f32(math.log2_f32(blur_size) / math.log2_f32(2))
		if denom == 0 {
			denom = 0.000001
		}
		fat_product := f32(math.pow(scale_factor, 1.0 / denom))

		alpha := blur_opacity / fat_product
		if alpha <= 0.001 {
			continue
		}

		fs := base_font_size * scale_factor
		sp := spacing * scale_factor

		size := rl.MeasureTextEx(font, fmt.ctprintf("{}", text), fs, sp)
		origin := rl.Vector2{size.x * 0.5, size.y * 0.5}

		y_offset := voff * (scale_factor - 1.0)

		rl.DrawTextPro(
			font,
			fmt.ctprintf("{}", text),
			rl.Vector2{center.x, center.y + y_offset},
			origin,
			0.0,
			fs,
			sp,
			with_alpha(glow_base, alpha),
		)
	}
	rl.EndBlendMode()

	rl.DrawTextPro(
		font,
		fmt.ctprintf("{}", text),
		center,
		base_origin,
		0.0,
		base_font_size,
		spacing,
		with_alpha(text_color, text_opacity),
	)
}

draw_shadow_bar :: proc(
	center_y: f32,
	rel_size: f32,
	opacity: f32,
	offset: f32,
	softness: f32,
	tint: rl.Color,
) {
	if rel_size <= 0.0 || opacity <= 0.0 {
		return
	}

	w := rl.GetScreenWidth()
	hf := f32(rl.GetScreenHeight())

	shadow_h := rel_size * 0.25 * hf
	center := center_y + offset * hf
	top := center - shadow_h * 0.5

	c_tint := rl.Color{tint.r, tint.g, tint.b, u8(clamp(opacity, 0, 1) * 255)}
	c_clear := rl.Color{tint.r, tint.g, tint.b, 0}

	y0 := i32(math.round(top))
	total_h := i32(math.round(shadow_h))
	if total_h <= 0 {
		return
	}
	y3 := y0 + total_h

	fade_h := shadow_h * clamp(softness, 0, 1) * 0.5
	fade_i := i32(math.round(fade_h))
	if fade_i * 2 > total_h {
		fade_i = total_h / 2
	}

	y1 := y0 + fade_i
	y2 := y3 - fade_i
	mid_h := y2 - y1

	rl.BeginBlendMode(.ALPHA)

	if fade_i > 0 {
		rl.DrawRectangleGradientV(0, y0, w, y1 - y0, c_clear, c_tint)
	}

	if mid_h > 0 {
		rl.DrawRectangle(0, y1, w, mid_h, c_tint)
	}

	if fade_i > 0 {
		rl.DrawRectangleGradientV(0, y2, w, y3 - y2, c_tint, c_clear)
	}

	rl.EndBlendMode()
}

draw_sheen_sweep :: proc(
	font: rl.Font,
	text: string,
	center: rl.Vector2,
	font_size: f32,
	spacing: f32,
	tint: rl.Color,
	progress: f32,
	core_frac: f32,
	soft_frac: f32,
	core_alpha: f32,
	soft_alpha: f32,
) {
	size := rl.MeasureTextEx(font, fmt.ctprintf("{}", text), font_size, spacing)
	origin := rl.Vector2{size.x * 0.5, size.y * 0.5}

	left := center.x - origin.x
	top := center.y - origin.y
	width := size.x
	height := size.y

	p := clamp(progress, 0, 1)

	x_center := left + width * p
	core_w := width * core_frac
	soft_w := width * soft_frac

	bright := rl.Color{255, 235, 210, 255}

	rl.BeginBlendMode(.ADDITIVE)

	rl.BeginScissorMode(i32(x_center - soft_w * 0.5), i32(top), i32(soft_w), i32(height))
	rl.DrawTextPro(
		font,
		fmt.ctprintf("{}", text),
		center,
		origin,
		0,
		font_size,
		spacing,
		with_alpha(bright, soft_alpha),
	)
	rl.EndScissorMode()

	rl.BeginScissorMode(i32(x_center - core_w * 0.5), i32(top), i32(core_w), i32(height))
	rl.DrawTextPro(
		font,
		fmt.ctprintf("{}", text),
		center,
		origin,
		0,
		font_size,
		spacing,
		with_alpha(bright, core_alpha),
	)
	rl.EndScissorMode()

	rl.EndBlendMode()
}

main :: proc() {
	mon := rl.GetCurrentMonitor()
	w, h := rl.GetMonitorWidth(mon), rl.GetMonitorHeight(mon)

	rl.SetConfigFlags(
		{
			.WINDOW_TRANSPARENT,
			.WINDOW_RESIZABLE,
			.WINDOW_MOUSE_PASSTHROUGH,
			.WINDOW_HIGHDPI,
			.WINDOW_TOPMOST,
			.WINDOW_UNFOCUSED,
			.WINDOW_UNDECORATED,
			.FULLSCREEN_MODE,
		},
	)
	rl.InitWindow(w, h, "amongus")

	rl.InitAudioDevice()
	music := rl.LoadMusicStreamFromMemory(".mp3", raw_data(SFX), i32(len(SFX)))
	rl.PlayMusicStream(music)

	rt := rl.LoadRenderTexture(rl.GetScreenWidth(), rl.GetScreenHeight())
	rl.SetTextureFilter(rt.texture, .BILINEAR)

	font := rl.LoadFontFromMemory(".otf", raw_data(OTF), i32(len(OTF)), 256, nil, 0)

	text := "NIXOS REBUILT"
	//base_font_size0 := f32(128)
	spacing := f32(2)
	text_color := rl.Color{235, 200, 120, 255}
	sheen_tint := rl.Color{255, 178, 153, 255}

	// base durations
	fade_in_dur := f32(0.55)
	scale_dur := f32(1.10)
	sweep_delay := f32(0.20)
	sweep_dur := f32(1.20)
	glow_rise_dur := f32(0.70)

	post_fade_in_dur := f32(0.25)
	post_hold_after_sweep := f32(0.35)
	post_fade_out_dur := f32(0.60)

	DUR_SCALE :: f32(2.0)

	blur_base := f32(1.0)
	blur_opacity_base := f32(0.08)

	// overlay appears 7s into the mp3
	OVERLAY_DELAY :: f32(5.0)

	SHEEN_GAIN :: 0.3 // overall intensity (0..1)
	SHEEN_W_SCALE :: 0.5 // width scaler (<1 = thinner)
	SHEEN_SOFT_ALPHA_CAP :: 0.10 // upper cap for soft halo
	SHEEN_CORE_ALPHA_CAP :: 0.28 // upper cap for core

	prev_mt := f32(0)
	ended := false
	len_s := f32(rl.GetMusicTimeLength(music))

	running := true
	for !rl.WindowShouldClose() && running {
		free_all(context.temp_allocator)

		if rl.IsWindowResized() {
			rl.UnloadRenderTexture(rt)
			rt = rl.LoadRenderTexture(rl.GetScreenWidth(), rl.GetScreenHeight())
			rl.SetTextureFilter(rt.texture, .BILINEAR)
		}

		rl.UpdateMusicStream(music)
		mt_raw := f32(rl.GetMusicTimePlayed(music))
		if !ended {
			if mt_raw < prev_mt - 0.02 ||
			   mt_raw >= len_s - 0.01 ||
			   (!rl.IsMusicStreamPlaying(music) && mt_raw > 0) {
				ended = true
				rl.StopMusicStream(music)
			}
		}
		mt := mt_raw
		if ended {
			mt = len_s
			running = false
		}
		prev_mt = mt_raw

		visible := mt >= OVERLAY_DELAY
		t := mt - OVERLAY_DELAY
		if t < 0 {t = 0}

		fade_in := fade_in_dur * DUR_SCALE
		scale_len := scale_dur * DUR_SCALE
		sweep_dly := sweep_delay * DUR_SCALE
		sweep_len := sweep_dur * DUR_SCALE
		glow_len := glow_rise_dur * DUR_SCALE
		post_in := post_fade_in_dur * DUR_SCALE
		post_hold := post_hold_after_sweep * DUR_SCALE
		post_out := post_fade_out_dur * DUR_SCALE

		alpha := ease.cubic_out(t / fade_in)
		scale_bump := 0.06 * ease_out_back(t / scale_len, 1.3)

		base_font_size0 := 0.6 * 0.25 * f32(rl.GetScreenHeight())
		font_size := base_font_size0 * (1.0 + scale_bump)

		glow_in := ease.cubic_out(t / glow_len)
		glow_pulse := 0.5 + 0.5 * f32(math.sin(t * 2.0))

		sweep_end_time := sweep_dly + sweep_len
		fade_out_start := sweep_end_time + post_hold

		blur_env := adsr(
			t,
			0.18 * DUR_SCALE, // attack
			0.35 * DUR_SCALE, // decay
			0.70, // sustain level
			fade_out_start, // release start
			post_out, // release dur
		)
		blur_size := blur_base * f32(math.lerp(f32(1.00), 1.30, ease.cubic_in_out(blur_env)))
		blur_opacity := blur_opacity_base
		blur_opacity *= (0.60 + 0.40 * blur_env) // grow with env
		blur_opacity *= clamp(glow_in * (0.8 + 0.2 * glow_pulse), 0.0, 1.0)

		sheen_t := t - sweep_dly

		raw_env := adsr(
			sheen_t,
			0.10 * DUR_SCALE,
			0.22 * DUR_SCALE,
			0.65,
			sweep_len,
			0.28 * DUR_SCALE,
		)
		sheen_env := f32(math.pow(clamp(raw_env, 0, 1), 0.75) * SHEEN_GAIN)

		core_frac := f32(math.lerp(f32(0.12), 0.18, sheen_env) * SHEEN_W_SCALE)
		soft_frac := f32(math.lerp(f32(0.24), 0.34, sheen_env) * SHEEN_W_SCALE)

		core_alpha_dyn := f32(
			math.min(math.lerp(f32(0.10), 0.26, sheen_env), SHEEN_CORE_ALPHA_CAP),
		)
		soft_alpha_dyn := f32(
			math.min(math.lerp(f32(0.03), 0.09, sheen_env), SHEEN_SOFT_ALPHA_CAP),
		)

		center := rl.Vector2{f32(rl.GetScreenWidth()) * 0.5, f32(rl.GetScreenHeight()) * 0.5}

		rl.BeginTextureMode(rt)
		rl.ClearBackground(rl.BLANK)

		if visible {
			draw_shadow_bar(center.y, 1.4, 0.95, -0.002, 0.5, rl.BLACK)

			draw_noun_verbed_sheen(
				font,
				text,
				center,
				font_size,
				spacing,
				text_color,
				alpha,
				sheen_tint,
				blur_size,
				blur_opacity,
			)

			sweep_p := clamp((t - sweep_dly) / sweep_len, 0, 1)
			if sweep_p > 0 && sweep_p <= 1 {
				draw_sheen_sweep(
					font,
					text,
					center,
					font_size,
					spacing,
					sheen_tint,
					sweep_p,
					core_frac,
					soft_frac,
					core_alpha_dyn,
					soft_alpha_dyn,
				)
			}
		}

		rl.EndTextureMode()

		post_alpha := f32(1.0)
		if !visible {
			post_alpha = 0
		} else {
			if t < post_in {
				post_alpha = ease.cubic_out(t / post_in)
			} else if t >= fade_out_start {
				post_alpha = 1.0 - ease.cubic_out((t - fade_out_start) / post_out)
			}
			post_alpha = clamp(post_alpha, 0, 1)
		}

		rl.BeginDrawing()
		rl.ClearBackground(rl.BLANK)

		src := rl.Rectangle{0, 0, f32(rt.texture.width), -f32(rt.texture.height)}
		dst := rl.Rectangle{0, 0, f32(rl.GetScreenWidth()), f32(rl.GetScreenHeight())}
		rl.DrawTexturePro(
			rt.texture,
			src,
			dst,
			rl.Vector2{0, 0},
			0,
			with_alpha(rl.WHITE, post_alpha),
		)

		rl.EndDrawing()
	}

	rl.UnloadRenderTexture(rt)
	rl.UnloadFont(font)
	rl.UnloadMusicStream(music)
	rl.CloseAudioDevice()
	rl.CloseWindow()
}