; ==============================================================================
; EBLAN ENGINE - Player Combat, Weapon Shooting & Combat HUD
; ==============================================================================

.code

DrawPixel PROTO :DWORD, :DWORD, :DWORD
DrawRect PROTO :DWORD, :DWORD, :DWORD, :DWORD, :DWORD
DrawRectOutline PROTO :DWORD, :DWORD, :DWORD, :DWORD, :DWORD
DrawString8x8 PROTO :DWORD, :DWORD, :DWORD, :DWORD
DrawNumber8x8 PROTO :DWORD, :DWORD, :DWORD, :DWORD

; ------------------------------------------------------------------------------
; UpdateCombat: Process weapon firing, hitscan raycasting, cooldowns & damage
; ------------------------------------------------------------------------------
UpdateCombat PROC uses ebx ecx edx esi edi
    LOCAL camCos:DWORD, camSin:DWORD
    LOCAL i:DWORD, closestIdx:DWORD, closestDist:DWORD
    LOCAL sprX:DWORD, sprY:DWORD
    LOCAL transX:DWORD, transY:DWORD
    LOCAL sprScreenX:DWORD, wallDepth:DWORD

    ; 1. Decrement cooldowns
    cmp playerAttackCooldown, 0
    je @F
    dec playerAttackCooldown
@@:
    cmp playerFlashTimer, 0
    je @F
    dec playerFlashTimer
@@:
    cmp playerHitFlash, 0
    je @F
    dec playerHitFlash
@@:

    ; If player is dead, cannot attack
    cmp isPlayerDead, 0
    jne combat_done

    ; 2. Check attack input
    cmp keyAttack, 0
    je combat_done
    cmp playerAttackCooldown, 0
    jne combat_done

    ; Check ammo
    cmp playerAmmo, 0
    jle combat_dry_fire

    ; Fire weapon!
    dec playerAmmo
    mov playerAttackCooldown, 10
    mov playerFlashTimer, 5

    ; 3. Hitscan check against enemies in center crosshair
    ; Camera basis for -playerAngle
    mov eax, ANGLE_512
    sub eax, playerAngle
    and eax, ANGLE_MASK
    mov ecx, [tableCos + eax*4]
    mov camCos, ecx
    mov edx, [tableSin + eax*4]
    mov camSin, edx

    ; Center wall depth from depthBuffer[160]
    mov eax, [depthBuffer + SCREEN_HALF_W * 4]
    mov wallDepth, eax

    mov closestIdx, -1
    mov closestDist, 999999

    mov i, 0
hitscan_loop:
    mov eax, i
    cmp eax, spriteCount
    jge hitscan_eval

    mov ecx, i
    mov eax, [entityType + ecx*4]
    cmp eax, ENTITY_TYPE_GUARD
    jne next_hitscan_target

    mov eax, [entityState + ecx*4]
    cmp eax, ENTITY_STATE_DEAD
    je next_hitscan_target

    mov ebx, i
    imul ebx, sizeof SpriteStruct
    add ebx, OFFSET spriteList

    mov eax, [ebx].SpriteStruct.textureId
    test eax, eax
    jz next_hitscan_target

    ; Transform to camera space
    mov eax, [ebx].SpriteStruct.x
    sub eax, playerX
    mov sprX, eax

    mov eax, [ebx].SpriteStruct.y
    sub eax, playerY
    mov sprY, eax

    ; transY = sprX * camCos - sprY * camSin
    mov eax, sprX
    imul camCos
    shrd eax, edx, 16
    mov ecx, eax
    mov eax, sprY
    imul camSin
    shrd eax, edx, 16
    sub ecx, eax
    mov transY, ecx

    ; Must be in front of player
    cmp transY, 16
    jle next_hitscan_target

    ; Must be closer than the wall at center screen
    mov eax, transY
    cmp eax, wallDepth
    jge next_hitscan_target

    ; transX = sprX * camSin + sprY * camCos
    mov eax, sprX
    imul camSin
    shrd eax, edx, 16
    mov ecx, eax
    mov eax, sprY
    imul camCos
    shrd eax, edx, 16
    add ecx, eax
    mov transX, ecx

    ; sprScreenX = (transX * PROJ_DIST) / transY + SCREEN_HALF_W
    mov eax, transX
    imul eax, PROJ_DIST
    cdq
    idiv transY
    add eax, SCREEN_HALF_W
    mov sprScreenX, eax

    ; Crosshair hitbox: within 22 pixels of center (SCREEN_HALF_W = 160)
    sub eax, SCREEN_HALF_W
    cdq
    xor eax, edx
    sub eax, edx        ; abs(sprScreenX - 160)
    cmp eax, 22
    jg next_hitscan_target

    ; Check if closer than previous target
    mov eax, transY
    cmp eax, closestDist
    jge next_hitscan_target
    mov closestDist, eax
    mov eax, i
    mov closestIdx, eax

next_hitscan_target:
    inc i
    jmp hitscan_loop

hitscan_eval:
    cmp closestIdx, -1
    je combat_done

    ; Apply damage to hit guard
    mov ecx, closestIdx
    mov eax, [entityHealth + ecx*4]
    sub eax, 35
    jns @F
    xor eax, eax
@@:
    mov [entityHealth + ecx*4], eax
    test eax, eax
    jnz combat_done

    ; Guard died!
    mov [entityState + ecx*4], ENTITY_STATE_DEAD
    mov DWORD PTR [entityTimer + ecx*4], 0
    add playerScore, 100

    ; Drop 10 ammo reward
    mov eax, playerAmmo
    add eax, 10
    cmp eax, playerMaxAmmo
    jle @F
    mov eax, playerMaxAmmo
@@:
    mov playerAmmo, eax
    jmp combat_done

combat_dry_fire:
    mov playerAttackCooldown, 12

combat_done:
    ret
UpdateCombat ENDP

; ------------------------------------------------------------------------------
; RenderCombatHUD: Renders health bar, ammo, crosshair, weapon & death screen
; ------------------------------------------------------------------------------
RenderCombatHUD PROC uses ebx ecx edx esi edi
    LOCAL barW:DWORD, gunY:DWORD

    ; 1. Center Crosshair (subtle cross at 160, 120)
    invoke DrawRect, 156, 120, 9, 1, 00FFFFFFh
    invoke DrawRect, 160, 116, 1, 9, 00FFFFFFh
    invoke DrawRect, 160, 120, 1, 1, 0000FF00h

    ; 2. Render Retro Weapon at bottom center
    mov gunY, 192
    cmp playerFlashTimer, 0
    je draw_gun_barrel
    ; Recoil offset
    add gunY, 3

    ; Muzzle Flash Burst (Bright yellow & white star)
    invoke DrawRect, 157, 165, 7, 18, 00FFFF00h
    invoke DrawRect, 152, 170, 17, 8, 00FFAA00h
    invoke DrawRect, 158, 168, 5, 12, 00FFFFFFh

draw_gun_barrel:
    ; Weapon barrel & slide
    invoke DrawRect, 154, gunY, 13, 28, 003A3A3Ah
    invoke DrawRect, 156, gunY, 9, 28, 00555555h
    invoke DrawRect, 158, gunY, 5, 28, 00777777h ; highlight strip
    ; Gun frame & grip
    mov eax, gunY
    add eax, 24
    invoke DrawRect, 150, eax, 21, 24, 00252525h
    mov eax, gunY
    add eax, 26
    invoke DrawRect, 152, eax, 17, 22, 00453020h ; brown wood grip plates

    ; 3. Health Bar
    invoke DrawString8x8, 8, 42, OFFSET strHpLabel, COLOR_GREEN
    invoke DrawNumber8x8, 34, 42, playerHealth, COLOR_WHITE

    invoke DrawRect, 68, 42, 60, 8, 00441010h
    invoke DrawRectOutline, 68, 42, 60, 8, COLOR_WHITE

    mov eax, playerHealth
    imul eax, 58
    xor edx, edx
    mov ecx, playerMaxHealth
    test ecx, ecx
    jnz @F
    mov ecx, 100
@@:
    div ecx
    mov barW, eax
    cmp barW, 0
    jle hud_ammo_draw
    cmp barW, 58
    jle @F
    mov barW, 58
@@:
    mov edx, 0000CC33h ; Green
    cmp playerHealth, 30
    jg @F
    mov edx, 00FF2222h ; Red warning
@@:
    invoke DrawRect, 69, 43, barW, 6, edx

hud_ammo_draw:
    ; 4. Ammo Display
    invoke DrawString8x8, 140, 42, OFFSET strAmmoLabel, COLOR_YELLOW
    invoke DrawNumber8x8, 182, 42, playerAmmo, COLOR_YELLOW

    ; 5. Score Display
    invoke DrawString8x8, 222, 42, OFFSET strScoreLabel, COLOR_CYAN
    invoke DrawNumber8x8, 272, 42, playerScore, COLOR_CYAN

    ; 6. Keys (if collected)
    cmp playerKeys, 0
    jle hud_damage_flash
    invoke DrawString8x8, 222, 10, OFFSET strKeysLabel, COLOR_MAGENTA
    invoke DrawNumber8x8, 258, 10, playerKeys, COLOR_MAGENTA

hud_damage_flash:
    ; 7. Damage Screen Flash
    cmp playerHitFlash, 0
    jle hud_death_check
    ; Red border vignette
    invoke DrawRect, 0, 0, SCREEN_W, 3, 00FF0000h
    invoke DrawRect, 0, 237, SCREEN_W, 3, 00FF0000h
    invoke DrawRect, 0, 0, 3, SCREEN_H, 00FF0000h
    invoke DrawRect, 317, 0, 3, SCREEN_H, 00FF0000h

hud_death_check:
    ; 8. Death Overlay Screen
    cmp isPlayerDead, 0
    je combat_hud_done

    invoke DrawRect, 20, 95, 280, 50, 00880000h
    invoke DrawRectOutline, 20, 95, 280, 50, COLOR_WHITE
    invoke DrawString8x8, 32, 114, OFFSET strYouDied, COLOR_YELLOW

combat_hud_done:
    ret
RenderCombatHUD ENDP