"""Default narration theme: icons per stage, green facts, blue paths."""

from . import register_theme

ICONS = [
    ('loading/', '⬇ '),
    ('dataset ready', '📦 '),
    ('few-shot', '✳ '),
    ('checkpoint', '◷ '),
    ('generation skipped', '⏭ '),
    ('generating', '🤖 '),
    ('generation complete', '✓ '),
    ('scoring', '★ '),
    ('writing', '📝 '),
    ('endpoint', '🔗 '),
]

FACT_COLOR = 'green'    # numbers/phrases/scores
PATH_COLOR = 'blue'     # filesystem locations


@register_theme('default')
def narrate(msg: str) -> str:
    import re

    low = msg.lower()
    icon = next((i for k, i in ICONS if k in low), '')

    def fact(text):
        return re.sub(r'(?<![\w/%.])(\d+(?:/\d+)?(?:\s+[a-z-]+){0,4})(?=[\s,.]|$)',
                      rf'[{FACT_COLOR}]\1[/{FACT_COLOR}]', text)

    m = re.search(r'[:·] ([a-zA-Z_@]+ [0-9.]+%)(?=\s|$)', msg)
    if m:
        head = f'{icon}{msg[:m.start()]}: [bold {FACT_COLOR}]{m.group(1)}[/bold {FACT_COLOR}]'
        return head + fact(msg[m.end():])
    for sep in ('-> ', 'to '):
        head, _, tail = msg.rpartition(sep)
        if head and tail.startswith('/'):
            return f'{icon}{head}{sep}[{PATH_COLOR}]{tail}[/{PATH_COLOR}]'
    return f'{icon}{fact(msg)}'