"""Default prompting for the user-selected ghibli-warm-painted direction."""

CHARACTER_STYLE = (
    'Studio Ghibli-inspired grounded coming-of-age animation, delicate expressive '
    'hand-drawn lines, rich warm watercolor-like painted shading, gentle luminous '
    'colors, restrained almond-shaped eyes and proportionate faces.'
)
BACKGROUND_STYLE = (
    'Studio Ghibli-inspired hand-painted background art, rich warm watercolor-like '
    'shading, gentle luminous colors, atmospheric depth, delicate expressive '
    'architectural detail, a welcoming lived-in storybook atmosphere.'
)
CHARACTER_PROMPT_TEMPLATE = (
    'vvar_char, one fictional character, {description}. '
    'Calm friendly expression, facing the viewer. Standing three-quarter portrait, '
    'head to thighs, hands and shoulders inside the frame, margin around the silhouette. '
    '{style} Perfectly uniform solid bright chroma green background, no scenery, '
    'no props, no shadow or gradient. Clothing contains no green or teal. '
    'No text, no logo, no watermark.'
)
BACKGROUND_PROMPT_TEMPLATE = (
    'vvar_bg, {description}. {style} Wide establishing view of an empty location. '
    'No people, no humans, no characters, no text, no watermark.'
)
DEFAULT_DESCRIPTIONS = {
    'characters': (
        'a mature-looking 17-year-old young Indian man, a late adolescent high-school '
        'senior with short dark hair, wearing a red hoodie and loose navy jeans, fully '
        'clothed and age-appropriate. The face reads as nearly adult: an elongated oval '
        'face, modest almond-shaped eyes, a subtly defined jaw, a proportionate head '
        'and long adolescent limbs'
    ),
    'backgrounds': (
        "A sunlit pottery workshop, clay bowls drying on wooden shelves, a potter's "
        'wheel, workbenches and a large window overlooking a garden'
    ),
}

def build_prompt(kind, description=None):
    """Use the recommended style unless the caller supplies a complete prompt.

    Descriptions must include the intended age and outfit for characters. Natural
    child anatomy should remain in school-child descriptions. No negative prompt
    is applied by default; the selected warm-painted examples use positive text.
    """
    if kind not in DEFAULT_DESCRIPTIONS:
        raise ValueError('kind must be characters or backgrounds')
    description = DEFAULT_DESCRIPTIONS[kind] if description is None else description.strip()
    if not description:
        raise ValueError('description must not be empty')
    template = CHARACTER_PROMPT_TEMPLATE if kind=='characters' else BACKGROUND_PROMPT_TEMPLATE
    style = CHARACTER_STYLE if kind=='characters' else BACKGROUND_STYLE
    return template.format(description=description.rstrip('. '), style=style)