package ui

import raylib "vendor:raylib"
import assets "../assets"
import audio "../audio"
import themes "../themes"

Font_Style :: assets.Font_Style

TEXT_SPACING :: 1

@(private)
any_hovered: bool

// Call at the start of each frame's drawing
begin_frame :: proc() {
    any_hovered = false
}

// Call at the end of each frame's drawing
end_frame :: proc() {
    raylib.SetMouseCursor(any_hovered ? .POINTING_HAND : .DEFAULT)
}

// Mark that something clickable is under the mouse (shows the hand cursor)
set_hovered :: proc() {
    any_hovered = true
}

measure_text :: proc(text: cstring, size: f32, style: Font_Style = .REGULAR) -> raylib.Vector2 {
    return raylib.MeasureTextEx(assets.get_font(style), text, size, TEXT_SPACING)
}

draw_text :: proc(text: cstring, pos: raylib.Vector2, size: f32, color: raylib.Color, style: Font_Style = .REGULAR) {
    raylib.DrawTextEx(assets.get_font(style), text, pos, size, TEXT_SPACING, color)
}

// Draws text horizontally centered on center_x with its top at y
draw_text_centered :: proc(text: cstring, center_x, y, size: f32, color: raylib.Color,
                           style: Font_Style = .REGULAR, shadow := false) {
    w := measure_text(text, size, style).x
    pos := raylib.Vector2{center_x - w / 2, y}
    if shadow {
        draw_text(text, pos + {0, size * 0.05}, size, raylib.Fade(themes.BLACK, 0.18), style)
    }
    draw_text(text, pos, size, color, style)
}

// Draws text centered in a rectangle
draw_text_in_rect :: proc(text: cstring, rect: raylib.Rectangle, size: f32, color: raylib.Color,
                          style: Font_Style = .REGULAR) {
    dims := measure_text(text, size, style)
    pos := raylib.Vector2{rect.x + (rect.width - dims.x) / 2, rect.y + (rect.height - dims.y) / 2}
    draw_text(text, pos, size, color, style)
}

draw_title :: proc(text: cstring, y: f32, color: raylib.Color, size: f32 = themes.TITLE_FONT_SIZE) {
    draw_text_centered(text, themes.SCREEN_WIDTH / 2, y, size, color, style = .BOLD, shadow = true)
}

// A rounded button with hover, press and shadow states. Returns true when clicked
// or when its hotkey is pressed.
button :: proc(rect: raylib.Rectangle, text: cstring, color: raylib.Color,
               text_color := themes.WHITE, font_size: f32 = themes.BUTTON_FONT_SIZE,
               hotkey := raylib.KeyboardKey.KEY_NULL, selected := false) -> bool {
    hovered := raylib.CheckCollisionPointRec(raylib.GetMousePosition(), rect)
    pressed := hovered && raylib.IsMouseButtonDown(.LEFT)
    if hovered { set_hovered() }

    lift: f32 = 0
    fill := color
    if hovered {
        lift = 2
        fill = raylib.ColorBrightness(color, 0.12)
    }
    if pressed {
        lift = -1
        fill = raylib.ColorBrightness(color, -0.08)
    }

    shadow := raylib.Rectangle{rect.x, rect.y + 4, rect.width, rect.height}
    raylib.DrawRectangleRounded(shadow, 0.4, 12, raylib.Fade(themes.BLACK, 0.18))
    body := raylib.Rectangle{rect.x, rect.y - lift, rect.width, rect.height}
    raylib.DrawRectangleRounded(body, 0.4, 12, fill)
    if selected {
        ring := raylib.Rectangle{body.x - 4, body.y - 4, body.width + 8, body.height + 8}
        raylib.DrawRectangleRoundedLinesEx(ring, 0.4, 12, 3, color)
    }
    draw_text_in_rect(text, body, font_size, text_color, style = .BOLD)

    clicked := hovered && raylib.IsMouseButtonPressed(.LEFT)
    if hotkey != .KEY_NULL && raylib.IsKeyPressed(hotkey) { clicked = true }
    if clicked { audio.play(.CLICK) }
    return clicked
}