// Kissaten Yūgure — stage 1 of the scope ladder (see docs/DESIGN.md §8):
// shop scene + one customer + siphon brew minigame + serve loop. No story,
// no money, no day cycle yet. All "art" is procedural placeholder fills;
// real bitmaps will replace the scene drawing and sprite data later.

//=============================================================================
// INCLUDES
//=============================================================================
#include "msxgl.h"

// Fonts data
#include "font/font_mgl_sample6.h"

//=============================================================================
// DEFINES
//=============================================================================

// Screen layout (DESIGN.md §4): 16px status bar, 132px shop scene, 64px dialogue
#define STATUS_Y		0
#define STATUS_H		16
#define SCENE_Y			16
#define SCENE_H			132
#define DLG_Y			148
#define DLG_H			64

// Palette slots (DESIGN.md §5: sky in 8-11, wood/warm in 4-7, so seasons and
// time-of-day can later be palette swaps without touching the bitmap)
#define C_OUTLINE		1	// near black
#define C_WOOD_D		2	// dark wood / floor / shadow
#define C_WOOD_M		3	// mid wood (wall panels, door)
#define C_WOOD_L		4	// light wood (counter top)
#define C_LAMP			5	// warm lamp glow
#define C_CREAM			6	// cream (glassware, cup)
#define C_WALL			7	// muted upper wall
#define C_SKY1			8	// dusk sky, deep
#define C_SKY2			9	// dusk violet
#define C_SKY3			10	// dusk rose
#define C_SKY4			11	// horizon amber
#define C_COFFEE		12	// coffee brown
#define C_COAT			13	// customer coat blue
#define C_SKIN			14	// skin
#define C_TEXT			15	// warm white

// G4 mode: one byte = two pixels of the same palette index
#define PX(c)			(u8)(((c) << 4) | (c))

// Shop scene landmarks
#define COUNTER_TOP_Y	98
#define DOOR_X			216	// where the customer appears/exits
#define SEAT_X			104	// where the customer stands at the counter
#define CUST_Y			84	// sprite top: bottom edge rests on the counter top
#define SIPHON_X		32	// siphon rig center
#define CUP_X			86	// served cup position on the counter

// Sprites (mode 2 is implicit in SCREEN 5; two layers per customer)
#define SPR_CUST_FILL	0	// front layer
#define SPR_CUST_LINE	1	// outline layer behind
#define SPR_STEAM		2
#define PAT_CUST_FILL	0	// 16x16 patterns: indices are multiples of 4
#define PAT_CUST_LINE	4
#define PAT_STEAM_A		8
#define PAT_STEAM_B		12

// Day length. Event-driven clock: customers *are* the clock, so this single
// constant is the whole pacing dial (PLAN.md §8 items 2-3).
#define CUSTOMERS_PER_DAY	5

// Brew minigame gauge (drawn in the dialogue window)
#define GAUGE_X			64
#define GAUGE_Y			186
#define GAUGE_W			148
#define GAUGE_H			10
#define GAUGE_CENTER	(GAUGE_W / 2)

// Dialogue text layout: 48px portrait zone left, 3 text lines right
#define DLG_TEXT_X		64
#define DLG_LINE_Y(n)	(u8)(156 + (n) * 14)

//=============================================================================
// READ-ONLY DATA
//=============================================================================

// Palette: u16 = G<<8 | R<<4 | B, components 0-7
#define RGB(r, g, b)	(u16)(((g) << 8) | ((r) << 4) | (b))
const u16 g_Palette[16] = {
	RGB(0, 0, 0),	// 0 (transparent)
	RGB(1, 1, 1),	// 1 outline
	RGB(2, 1, 1),	// 2 dark wood
	RGB(4, 2, 1),	// 3 mid wood
	RGB(5, 3, 2),	// 4 light wood
	RGB(7, 5, 2),	// 5 lamp glow
	RGB(7, 6, 4),	// 6 cream
	RGB(3, 2, 2),	// 7 muted wall
	RGB(2, 1, 4),	// 8 dusk deep
	RGB(4, 2, 5),	// 9 dusk violet
	RGB(6, 3, 3),	// 10 dusk rose
	RGB(7, 4, 2),	// 11 horizon amber
	RGB(3, 1, 0),	// 12 coffee
	RGB(2, 3, 5),	// 13 coat blue
	RGB(7, 5, 4),	// 14 skin
	RGB(7, 7, 6),	// 15 warm white
};

// 16x16 sprite patterns: 32 bytes each, left column rows 0-15 then right column.
// Customer silhouette, fill layer
const u8 g_SprCustFill[32] = {
	0x07, 0x0F, 0x1F, 0x1F, 0x1F, 0x0F, 0x07, 0x1F,	// left, rows 0-7
	0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x1F, 0x0E, 0x0E,	// left, rows 8-15
	0xE0, 0xF0, 0xF8, 0xF8, 0xF8, 0xF0, 0xE0, 0xF8,	// right, rows 0-7
	0xFC, 0xFC, 0xFC, 0xFC, 0xFC, 0xF8, 0x70, 0x70,	// right, rows 8-15
};
// Customer silhouette dilated by 1px: black outline layer drawn behind the fill
const u8 g_SprCustLine[32] = {
	0x1F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x7F,
	0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x3F, 0x1F,
	0xF8, 0xFC, 0xFC, 0xFC, 0xFC, 0xFC, 0xFC, 0xFE,
	0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFC, 0xF8,
};
// Steam wisps, two animation frames
const u8 g_SprSteamA[32] = {
	0x01, 0x03, 0x07, 0x0E, 0x1C, 0x1E, 0x0F, 0x07,
	0x03, 0x03, 0x07, 0x0E, 0x06, 0x00, 0x00, 0x00,
	0x80, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80,
	0xC0, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
const u8 g_SprSteamB[32] = {
	0x01, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
	0x03, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x80, 0xC0, 0xE0, 0x70, 0x38, 0x78, 0xF0, 0xE0,
	0xC0, 0xC0, 0xE0, 0x70, 0x60, 0x00, 0x00, 0x00,
};

// Ambient lines shown while the shop is empty
const c8* const g_Ambient[4] = {
	"The radio hums softly.",
	"Rain taps at the window.",
	"The kettle ticks as it cools.",
	"Dusk settles over the street.",
};

//=============================================================================
// GAME STATE
//=============================================================================

enum State
{
	STATE_WAIT,		// shop empty, waiting for the next customer
	STATE_ARRIVE,	// customer walks from door to counter
	STATE_ORDER,	// order shown, waiting for SPACE
	STATE_BREW,		// siphon minigame running
	STATE_SERVE,	// reaction to the brew
	STATE_DRINK,	// quiet moment with the cup
	STATE_LEAVE,	// customer walks back to the door
};

// Day phases (DESIGN.md §2). The open-hours phase holds the STATE_* loop above.
enum Phase
{
	PHASE_MORNING,	// prep — day title card, waiting to open
	PHASE_OPEN,		// the serve loop runs
	PHASE_EVENING,	// close — tally, journal line, save
};

u8  g_State = STATE_WAIT;
u16 g_Timer = 120;			// frames left in timed states
u8  g_CustX = DOOR_X;		// customer sprite X
u16 g_Served = 0;			// cups served, lifetime
u8  g_Ambience = 0;			// rotating ambient line index
i16 g_Needle = 0;			// brew gauge needle position
i8  g_NeedleDir = 3;
u8  g_Quality = 0;			// 0 weak/overdone .. 3 perfect
bool g_Overdone = FALSE;	// which side of center the lock landed on
u8  g_Frame = 0;
bool g_SpaceHit = FALSE;	// SPACE pressed this frame (edge, sampled after Halt)
u8  g_SpacePrev = 0;

u8  g_Phase = PHASE_MORNING;
u8  g_DayServed = 0;		// customers served so far today
u8  g_DayQuality = 0;		// summed brew quality today, for the journal line
u8  g_DiskErr = 0;			// last disk error code (0 = fine)
bool g_HasDisk = FALSE;		// a usable save disk was found at boot

//=============================================================================
// SAVE STATE  (DESIGN.md §6)
//=============================================================================

// Bumped whenever the layout below changes; a mismatch is treated as "no save"
// rather than migrated — there is no shipped version to be compatible with yet.
#define SAVE_MAGIC		0x594B		// 'KY'
#define SAVE_VERSION	1

typedef struct
{
	u8  id;
	u8  arc_stage;		// progress through their story
	u8  affinity;		// 0-255, raised by right orders
	u8  last_visit_day;
} Regular;

typedef struct
{
	u16 magic;
	u8  version;
	u16 day;
	u8  season;			// derives palette set
	u8  weather;		// affects visitor table
	u16 money;
	u16 served;
	u8  unlocked_items;	// bitmask: grinder, records, cat...
	Regular regulars[8];
	u8  checksum;		// sum of all preceding bytes, negated
} SaveState;

SaveState g_Save;

// One 512-byte sector staging buffer. Must live in RAM (page 3) — PHYDIO
// writes straight into it, and pages 1-2 are ROM on a cartridge target.
u8 g_Sector[512];

// Sector holding the save, derived from the disk's own BPB at boot rather
// than hardcoded, so a 360K disk works as well as the 720K one.
u16 g_SaveSector = 14;

//=============================================================================
// DISK ACCESS
//=============================================================================

// Number of disk drives, maintained by the Disk ROM at boot. Zero means there
// is no disk interface at all — and on such a machine (C-BIOS, for one) the
// PHYDIO hook is not patched and calling it is not safe.
#define M_NMBDRV_ADDR	0xF347
#define M_MASTER_ADDR	0xF348		// main Disk ROM slot, 0 if there is none

// PHYDIO trampoline, executed from RAM.
//
// PHYDIO (Main-ROM 0144h) reaches the Disk ROM through an inter-slot call, and
// the Disk ROM lives at 4000h — the same page as this cartridge. For the
// duration of the call our ROM is switched out of page 1, so the instruction
// making the call must not itself be in page 1. Copying these twelve bytes to
// RAM and calling *them* keeps the call site alive across the switch.
u8 g_DiskStub[21];

void Disk_InitStub()
{
	// Calls DSKIO (Disk ROM 4010h) through CALSLT rather than the Main ROM's
	// PHYDIO wrapper at 0144h: PHYDIO jumps to a RAM hook that this machine
	// leaves unpatched, so it returns carry-clear — reporting success while
	// never touching the buffer. Going straight at the Disk ROM avoids it.
	//
	// IY high byte must hold the slot ID, and MASTER lives at F348h, so a
	// word load from F347h lands it in IYh exactly as CALSLT wants.
	static const u8 code[21] =
	{
		0xF3,							// di
		0xFD, 0x2A, 0x47, 0xF3,			// ld iy, (0xF347) ; IYh = MASTER
		0xDD, 0x21, 0x10, 0x40,			// ld ix, #0x4010  ; DSKIO
		0xCD, 0x1C, 0x00,				// call 0x001C     ; CALSLT
		0x38, 0x04,						// jr c, err
		0x2E, 0x00,						// ld l, #0        ; success
		0xFB,							// ei
		0xC9,							// ret
		0x6F,							// err: ld l, a    ; BIOS error code
		0xFB,							// ei
		0xC9,							// ret
	};
	Mem_Copy(code, g_DiskStub, sizeof(code));
}

//-----------------------------------------------------------------------------
// Absolute sector read/write into g_Sector.
//   carry clear = read, carry set = write
//   A=drive B=sector count C=media ID DE=first sector HL=buffer
// Returns the BIOS error code, or 0 on success.
u8 Disk_Access(u16 sector, u8 write) __NAKED
{
	sector;	// on stack
	write;

__asm
	push	ix
	ld		ix, #0
	add		ix, sp

	ld		e, 4(ix)			// sector low
	ld		d, 5(ix)			// sector high
	ld		a, 6(ix)			// write flag

	ld		hl, #_g_Sector
	ld		b, #1				// one sector
	ld		c, #0xF9			// media ID: 720K DS/DD
	or		a					// test flag; also clears carry (= read)
	jr		z, phydio_go
	scf							// carry set = write
phydio_go:
	ld		a, #0				// drive A:. 'ld a,n' preserves flags
	call	_g_DiskStub			// -> PHYDIO, from RAM. Returns code in L

	pop		ix
	ret
__endasm;
}

//-----------------------------------------------------------------------------
// Read the BIOS Parameter Block and work out where the data area starts.
// Returns FALSE if no disk responded at all.
bool Disk_Probe()
{
	u8 drives = *(const u8*)M_NMBDRV_ADDR;

	// Both of these are set by the Disk ROM's INIT. Without them the entry
	// points below are not safe to call — on C-BIOS this work area is never
	// initialised at all, and calling anyway black-screens the machine.
	if (drives == 0 || drives > 8)
		return FALSE;
	if (*(const u8*)M_MASTER_ADDR == 0)
		return FALSE;

	Disk_InitStub();

	// Sentinel: the disk entry points can return carry-clear ("success")
	// without having touched the buffer, so a clean error code is not on its
	// own proof that a read happened. Verify the buffer actually changed.
	Mem_Set(0xAA, g_Sector, 16);
	g_DiskErr = Disk_Access(0, 0);
	if (g_DiskErr != 0)
		return FALSE;
	if (g_Sector[0] == 0xAA && g_Sector[11] == 0xAA)
		return FALSE;	// nothing was read; treat the disk as unusable

	u16 bytesPerSec  = g_Sector[11] | ((u16)g_Sector[12] << 8);
	u16 reserved     = g_Sector[14] | ((u16)g_Sector[15] << 8);
	u8  numFATs      = g_Sector[16];
	u16 rootEntries  = g_Sector[17] | ((u16)g_Sector[18] << 8);
	u16 secPerFAT    = g_Sector[22] | ((u16)g_Sector[23] << 8);

	if (bytesPerSec != 512)		// anything else is not a disk we made
		return FALSE;

	// Root directory occupies ceil(entries * 32 / 512) sectors
	u16 rootSecs = (u16)((rootEntries + 15) >> 4);
	g_SaveSector = reserved + (u16)numFATs * secPerFAT + rootSecs;
	return TRUE;
}

//-----------------------------------------------------------------------------
u8 Save_Checksum(const SaveState* s)
{
	const u8* p = (const u8*)s;
	u8 sum = 0;
	for (u8 i = 0; i < sizeof(SaveState) - 1; i++)
		sum += p[i];
	return (u8)(0 - sum);
}

//-----------------------------------------------------------------------------
// TRUE if a valid save was loaded; FALSE means "start a new game", which is
// also what a blank disk gives us — no error path for the player to hit.
bool Save_Load()
{
	if (!g_HasDisk)
		return FALSE;

	g_DiskErr = Disk_Access(g_SaveSector, 0);
	if (g_DiskErr != 0)
		return FALSE;

	SaveState* s = (SaveState*)g_Sector;
	if (s->magic != SAVE_MAGIC || s->version != SAVE_VERSION)
		return FALSE;
	if (s->checksum != Save_Checksum(s))
		return FALSE;

	Mem_Copy(s, &g_Save, sizeof(SaveState));
	return TRUE;
}

//-----------------------------------------------------------------------------
bool Save_Write()
{
	if (!g_HasDisk)
		return FALSE;

	g_Save.magic    = SAVE_MAGIC;
	g_Save.version  = SAVE_VERSION;
	g_Save.checksum = Save_Checksum(&g_Save);

	Mem_Set(0, g_Sector, sizeof(g_Sector));
	Mem_Copy(&g_Save, g_Sector, sizeof(SaveState));

	g_DiskErr = Disk_Access(g_SaveSector, 1);
	return (g_DiskErr == 0);
}

//-----------------------------------------------------------------------------
void Save_Reset()
{
	Mem_Set(0, &g_Save, sizeof(SaveState));
	g_Save.day    = 1;
	g_Save.season = 0;
	g_Save.money  = 0;
	g_Save.served = 0;
	for (u8 i = 0; i < 8; i++)
		g_Save.regulars[i].id = i;
}

//=============================================================================
// HELPERS
//=============================================================================

//-----------------------------------------------------------------------------
// Customer sprites: fill layer in front, outline layer behind
void Customer_Show(u8 x, u8 y)
{
	VDP_SetSpritePosition(SPR_CUST_FILL, x, y);
	VDP_SetSpritePosition(SPR_CUST_LINE, x, y);
}

void Customer_Hide()
{
	VDP_HideSprite(SPR_CUST_FILL);
	VDP_HideSprite(SPR_CUST_LINE);
}

//-----------------------------------------------------------------------------
// Steam wisp: alternates two patterns every 16 frames
void Steam_Show(u8 x, u8 y)
{
	VDP_SetSpriteExUniColor(SPR_STEAM, x, y,
		(g_Frame & 16) ? PAT_STEAM_A : PAT_STEAM_B, C_CREAM);
}

void Steam_Hide()
{
	VDP_HideSprite(SPR_STEAM);
}

//-----------------------------------------------------------------------------
// Status bar: title left, served count right
void DrawStatusBar()
{
	VDP_CommandHMMV(0, STATUS_Y, 256, STATUS_H, PX(C_OUTLINE));
	VDP_CommandWait();

	Print_SetColor(C_LAMP, C_OUTLINE);
	Print_SetPosition(4, 4);
	Print_DrawText("DAY ");
	Print_DrawInt(g_Save.day);

	// Phase marker sits mid-bar; the clock is the day phase, nothing finer
	Print_SetColor(C_CREAM, C_OUTLINE);
	Print_SetPosition(96, 4);
	switch (g_Phase)
	{
	case PHASE_MORNING:	Print_DrawText("MORNING"); break;
	case PHASE_OPEN:	Print_DrawText("OPEN");    break;
	default:			Print_DrawText("CLOSED");  break;
	}

	Print_SetColor(C_TEXT, C_OUTLINE);
	Print_SetPosition(176, 4);
	Print_DrawText("SERVED ");
	Print_DrawInt(g_Save.served);
}

//-----------------------------------------------------------------------------
// Shop scene: placeholder fills standing in for the real background bitmap
void DrawScene()
{
	// Wall, wood paneling, floor
	VDP_CommandHMMV(0, SCENE_Y, 256, 60, PX(C_WALL));				// upper wall
	VDP_CommandHMMV(0, 76, 256, 44, PX(C_WOOD_M));					// wainscot
	VDP_CommandHMMV(0, 76, 256, 1, PX(C_WOOD_D));					// panel rail
	VDP_CommandHMMV(0, 120, 256, 28, PX(C_WOOD_D));					// floor
	VDP_CommandHMMV(0, 120, 256, 1, PX(C_OUTLINE));					// floor edge

	// Window (left): frame + dusk sky gradient in slots 8-11
	VDP_CommandHMMV(16, 24, 72, 48, PX(C_WOOD_D));					// frame
	VDP_CommandHMMV(20, 28, 64, 10, PX(C_SKY1));
	VDP_CommandHMMV(20, 38, 64, 10, PX(C_SKY2));
	VDP_CommandHMMV(20, 48, 64, 10, PX(C_SKY3));
	VDP_CommandHMMV(20, 58, 64, 10, PX(C_SKY4));
	VDP_CommandHMMV(50, 28, 2, 40, PX(C_WOOD_D));					// mullion
	VDP_CommandHMMV(20, 46, 64, 2, PX(C_WOOD_D));					// transom

	// Door (right)
	VDP_CommandHMMV(208, 32, 36, 88, PX(C_WOOD_D));					// frame
	VDP_CommandHMMV(212, 36, 28, 82, PX(C_WOOD_M));					// door
	VDP_CommandHMMV(218, 40, 16, 18, PX(C_SKY2));					// door pane
	VDP_CommandHMMV(236, 76, 2, 3, PX(C_LAMP));						// knob

	// Hanging lamp above the counter
	VDP_CommandHMMV(139, SCENE_Y, 2, 12, PX(C_OUTLINE));			// cord
	VDP_CommandHMMV(132, 28, 16, 8, PX(C_LAMP));					// shade

	// Counter: top slab + front panel
	VDP_CommandHMMV(8, COUNTER_TOP_Y, 192, 8, PX(C_WOOD_L));
	VDP_CommandHMMV(8, COUNTER_TOP_Y + 8, 192, 34, PX(C_WOOD_D));
	VDP_CommandHMMV(8, COUNTER_TOP_Y, 192, 1, PX(C_CREAM));		// top highlight

	// Siphon rig on the counter (left, kept below the window): stand, globe, flask
	VDP_CommandHMMV(SIPHON_X + 5, 74, 2, 24, PX(C_OUTLINE));		// stand pole
	VDP_CommandHMMV(SIPHON_X - 6, 74, 24, 2, PX(C_OUTLINE));		// top arm
	VDP_CommandHMMV(SIPHON_X - 6, 76, 12, 8, PX(C_CREAM));		// upper globe
	VDP_CommandHMMV(SIPHON_X - 7, 86, 14, 10, PX(C_CREAM));		// lower flask
	VDP_CommandWait();
}

//-----------------------------------------------------------------------------
// Coffee level in the lower flask, 0-8 px
void DrawFlask(u8 level)
{
	VDP_CommandHMMV(SIPHON_X - 6, 87, 12, 8, PX(C_CREAM));
	if (level > 0)
	{
		if (level > 8)
			level = 8;
		VDP_CommandHMMV(SIPHON_X - 6, (u16)(95 - level), 12, level, PX(C_COFFEE));
	}
	VDP_CommandWait();
}

//-----------------------------------------------------------------------------
// Burner flame under the flask (on/off)
void DrawFlame(bool on)
{
	VDP_CommandHMMV(SIPHON_X - 3, 96, 6, 2, on ? PX(C_SKY4) : PX(C_WOOD_M));
	VDP_CommandWait();
}

//-----------------------------------------------------------------------------
// Cup on the counter in front of the customer
void DrawCup(bool visible)
{
	if (visible)
	{
		VDP_CommandHMMV(CUP_X, 91, 10, 7, PX(C_CREAM));
		VDP_CommandHMMV(CUP_X + 1, 91, 8, 2, PX(C_COFFEE));
	}
	else	// restore the wainscot the cup stands against, not the counter top
		VDP_CommandHMMV(CUP_X, 91, 10, 7, PX(C_WOOD_M));
	VDP_CommandWait();
}

//-----------------------------------------------------------------------------
// Dialogue window: dark panel with a portrait placeholder box on the left
void Dlg_Clear()
{
	VDP_CommandHMMV(0, DLG_Y, 256, DLG_H, PX(C_WOOD_D));			// border
	VDP_CommandHMMV(2, DLG_Y + 2, 252, DLG_H - 4, PX(C_OUTLINE));	// panel
	VDP_CommandHMMV(6, 154, 52, 52, PX(C_WOOD_M));					// portrait frame
	VDP_CommandHMMV(8, 156, 48, 48, PX(C_WOOD_D));					// portrait (48x48, stage 3+)
	VDP_CommandWait();
}

void Dlg_Line(u8 line, const c8* text)
{
	Print_SetColor(C_TEXT, C_OUTLINE);
	Print_SetPosition(DLG_TEXT_X, DLG_LINE_Y(line));
	Print_DrawText(text);
}

// Prompt line in warm accent color
void Dlg_Prompt(const c8* text)
{
	Print_SetColor(C_LAMP, C_OUTLINE);
	Print_SetPosition(DLG_TEXT_X, DLG_LINE_Y(3));
	Print_DrawText(text);
}

//-----------------------------------------------------------------------------
// Brew gauge: zones repainted whole each frame, then the needle on top
void DrawGauge()
{
	// Full band first: the needle sticks out 2px above and below the zones
	VDP_CommandHMMV(GAUGE_X, GAUGE_Y - 2, GAUGE_W + 2, GAUGE_H + 4, PX(C_OUTLINE));
	VDP_CommandHMMV(GAUGE_X, GAUGE_Y, GAUGE_W, GAUGE_H, PX(C_WOOD_D));
	VDP_CommandHMMV(GAUGE_X + GAUGE_CENTER - 10, GAUGE_Y, 20, GAUGE_H, PX(C_LAMP));
	VDP_CommandHMMV(GAUGE_X + GAUGE_CENTER - 3, GAUGE_Y, 6, GAUGE_H, PX(C_SKY4));
	VDP_CommandHMMV((u16)(GAUGE_X + g_Needle), GAUGE_Y - 2, 2, GAUGE_H + 4, PX(C_TEXT));
	VDP_CommandWait();
}

void EraseGauge()
{
	VDP_CommandHMMV(GAUGE_X, GAUGE_Y - 2, GAUGE_W + 2, GAUGE_H + 4, PX(C_OUTLINE));
	VDP_CommandWait();
}

//=============================================================================
// PHASE TRANSITIONS
//=============================================================================

//-----------------------------------------------------------------------------
// Morning: day title card. No prep decisions yet — those arrive with the menu
// system, if it survives the cut (PLAN.md §6).
void EnterMorning()
{
	g_Phase = PHASE_MORNING;
	g_DayServed = 0;
	g_DayQuality = 0;
	Customer_Hide();
	Steam_Hide();
	DrawStatusBar();
	DrawScene();
	Dlg_Clear();
	Dlg_Line(0, "Morning. The shutters go");
	Dlg_Line(1, "up, the kettle goes on.");
	Dlg_Prompt("[SPACE] open the shop");
}

//-----------------------------------------------------------------------------
// Evening: tally, one journal line reflecting how the day went, then save.
void EnterEvening()
{
	g_Phase = PHASE_EVENING;
	Customer_Hide();
	Steam_Hide();
	DrawStatusBar();
	Dlg_Clear();

	Dlg_Line(0, "Closing. Cups today: ");
	Print_DrawInt(g_DayServed);

	// Average quality drives the journal line — no score, just a mood
	u8 avg = g_DayServed ? (u8)(g_DayQuality / g_DayServed) : 0;
	if (avg >= 2)
		Dlg_Line(1, "A good day at the siphon.");
	else if (avg >= 1)
		Dlg_Line(1, "An ordinary, decent day.");
	else
		Dlg_Line(1, "Tomorrow, a steadier hand.");

	if (Save_Write())
		Dlg_Prompt("[SPACE] sleep  (saved)");
	else if (!g_HasDisk)
		Dlg_Prompt("[SPACE] sleep  (no disk)");
	else
		Dlg_Prompt("[SPACE] sleep  (SAVE FAILED)");
}

//-----------------------------------------------------------------------------
void AdvanceDay()
{
	g_Save.day++;
	EnterMorning();
}

//=============================================================================
// STATE TRANSITIONS
//=============================================================================

void EnterWaitState()
{
	g_State = STATE_WAIT;
	g_Timer = 120 + Math_GetRandomMax8(180);
	Dlg_Clear();
	Dlg_Line(0, g_Ambient[g_Ambience]);
	g_Ambience = (g_Ambience + 1) & 3;
}

void EnterArrive()
{
	g_State = STATE_ARRIVE;
	g_CustX = DOOR_X;
	VDP_SetSpriteExUniColor(SPR_CUST_LINE, DOOR_X, CUST_Y, PAT_CUST_LINE, C_OUTLINE);
	VDP_SetSpriteExUniColor(SPR_CUST_FILL, DOOR_X, CUST_Y, PAT_CUST_FILL, C_COAT);
	Dlg_Clear();
	Dlg_Line(0, "The door chime rings.");
}

void EnterOrder()
{
	g_State = STATE_ORDER;
	Dlg_Clear();
	Dlg_Line(0, "\"A coffee, please.\"");
	Dlg_Prompt("[SPACE] brew");
}

void EnterBrew()
{
	g_State = STATE_BREW;
	g_Needle = 0;
	g_NeedleDir = 3;
	g_Timer = 0;
	Dlg_Clear();
	Dlg_Line(0, "Release when the needle");
	Dlg_Line(1, "crosses the amber mark!");
	DrawFlame(TRUE);
}

void EnterServe()
{
	g_State = STATE_SERVE;
	g_Timer = 150;
	EraseGauge();
	DrawFlame(FALSE);
	DrawFlask(0);
	DrawCup(TRUE);
	Dlg_Clear();
	switch (g_Quality)
	{
	case 3:
		Dlg_Line(0, "\"Ah... perfect.\"");
		Dlg_Line(1, "The evening feels warmer.");
		break;
	case 2:
		Dlg_Line(0, "\"Mm. Nice and rich.\"");
		break;
	case 1:
		Dlg_Line(0, "\"Thank you.\"");
		break;
	default:
		Dlg_Line(0, g_Overdone ? "\"Oh... quite strong.\""
		                       : "\"Hm... a little thin.\"");
		break;
	}
}

void EnterDrink()
{
	g_State = STATE_DRINK;
	g_Timer = 180;
	Dlg_Clear();
	Dlg_Line(0, "A quiet moment passes.");
}

void EnterLeave()
{
	g_State = STATE_LEAVE;
	Steam_Hide();
	DrawCup(FALSE);
	Dlg_Clear();
	Dlg_Line(0, "\"See you tomorrow.\"");
}

//=============================================================================
// STATE UPDATES (one call per frame)
//=============================================================================

void UpdateWait()
{
	if (--g_Timer == 0)
		EnterArrive();
}

void UpdateArrive()
{
	g_CustX--;
	// Small walk bob
	Customer_Show(g_CustX, (g_CustX & 8) ? CUST_Y : CUST_Y - 1);
	if (g_CustX <= SEAT_X)
	{
		Customer_Show(SEAT_X, CUST_Y);
		EnterOrder();
	}
}

void UpdateOrder()
{
	if (g_SpaceHit)
		EnterBrew();
}

void UpdateBrew()
{
	// Needle sweeps back and forth
	g_Needle += g_NeedleDir;
	if (g_Needle <= 0)			{ g_Needle = 0;           g_NeedleDir = 3;  }
	if (g_Needle >= GAUGE_W - 2){ g_Needle = GAUGE_W - 2; g_NeedleDir = -3; }
	DrawGauge();

	// Coffee slowly rises while the needle sweeps
	g_Timer++;
	if ((g_Timer & 15) == 0)
		DrawFlask((u8)(g_Timer >> 4));
	Steam_Show(SIPHON_X - 8, 58);

	if (g_SpaceHit)
	{
		i16 dist = g_Needle + 1 - GAUGE_CENTER;
		g_Overdone = (dist > 0);
		if (dist < 0)
			dist = -dist;
		if      (dist <= 3)  g_Quality = 3;
		else if (dist <= 10) g_Quality = 2;
		else if (dist <= 24) g_Quality = 1;
		else                 g_Quality = 0;
		g_DayQuality += g_Quality;
		EnterServe();
	}
}

void UpdateServe()
{
	Steam_Show(CUP_X - 4, 78);
	if (--g_Timer == 0)
		EnterDrink();
}

void UpdateDrink()
{
	Steam_Show(CUP_X - 4, 78);
	if (--g_Timer == 0)
		EnterLeave();
}

void UpdateLeave()
{
	g_CustX++;
	Customer_Show(g_CustX, (g_CustX & 8) ? CUST_Y : CUST_Y - 1);
	if (g_CustX >= DOOR_X)
	{
		Customer_Hide();
		g_Save.served++;
		g_DayServed++;
		DrawStatusBar();

		// Customers are the clock: the day ends when the last one leaves
		if (g_DayServed >= CUSTOMERS_PER_DAY)
			EnterEvening();
		else
			EnterWaitState();
	}
}

//=============================================================================
// MAIN LOOP
//=============================================================================

//-----------------------------------------------------------------------------
// Program entry point
void main()
{
	VDP_SetMode(VDP_MODE_SCREEN5);
	VDP_SetColor(C_OUTLINE);
	VDP_EnableVBlank(TRUE);
	VDP_ClearVRAM();

	// Palette (skip entry 0: transparent)
	for (u8 i = 1; i < 16; i++)
		VDP_SetPaletteEntry(i, g_Palette[i]);

	// Sprites: 16x16, tables above page 1 (page 1 becomes the asset warehouse later)
	VDP_EnableSprite(TRUE);
	VDP_SetSpritePatternTable(0x17000);
	VDP_SetSpriteAttributeTable(0x17A00);
	VDP_SetSpriteFlag(VDP_SPRITE_SIZE_16);
	VDP_LoadSpritePattern(g_SprCustFill, PAT_CUST_FILL, 4);
	VDP_LoadSpritePattern(g_SprCustLine, PAT_CUST_LINE, 4);
	VDP_LoadSpritePattern(g_SprSteamA, PAT_STEAM_A, 4);
	VDP_LoadSpritePattern(g_SprSteamB, PAT_STEAM_B, 4);
	VDP_HideAllSprites();
	VDP_DisableSpritesFrom(3);

	Print_SetBitmapFont(g_Font_MGL_Sample6);

	// Explicit game-state init: don't rely on C initializers, the mapper
	// crt0's data-segment setup has proven unreliable here.
	g_Served = 0;
	g_Ambience = 0;
	g_Frame = 0;
	g_SpaceHit = FALSE;
	g_SpacePrev = 1;	// treat SPACE as held at boot: no phantom first edge
	g_DiskErr = 0;
	g_SaveSector = 14;

	// Save disk. A missing or blank disk is not an error the player has to
	// deal with — it just means today is day one and nothing will persist.
	Save_Reset();
	g_HasDisk = Disk_Probe();
	Save_Load();

	EnterMorning();

	while (1)
	{
		Halt(); // Wait V-Blank
		g_Frame++;

		// Sample input immediately after Halt(): the BIOS ISR drives the PPI
		// keyboard row selection too, so a read elsewhere in the frame can
		// race with it and produce phantom edges.
		// Atomic keyboard read: Keyboard_Read() is a row-select 'out' followed
		// by an 'in'; if the BIOS ISR lands between them, its own matrix scan
		// moves the row selection and the read returns garbage (phantom keys).
		DisableInterrupt();
		u8 raw = Keyboard_Read(KEY_ROW(KEY_SPACE));
		EnableInterrupt();
		u8 space = (raw & KEY_FLAG(KEY_SPACE)) == 0;
		g_SpaceHit = space && !g_SpacePrev;
		g_SpacePrev = space;

		// Morning and evening are single-key card screens; only the open
		// phase runs the serve loop's state machine.
		if (g_Phase == PHASE_MORNING)
		{
			if (g_SpaceHit)
			{
				g_Phase = PHASE_OPEN;
				DrawStatusBar();
				EnterWaitState();
			}
			continue;
		}
		if (g_Phase == PHASE_EVENING)
		{
			if (g_SpaceHit)
				AdvanceDay();
			continue;
		}

		switch (g_State)
		{
		case STATE_WAIT:	UpdateWait();	break;
		case STATE_ARRIVE:	UpdateArrive();	break;
		case STATE_ORDER:	UpdateOrder();	break;
		case STATE_BREW:	UpdateBrew();	break;
		case STATE_SERVE:	UpdateServe();	break;
		case STATE_DRINK:	UpdateDrink();	break;
		case STATE_LEAVE:	UpdateLeave();	break;
		}
	}
}