import gradio as gr

# --- Minimal Sanskrit lexicon (extend with real data) ---
LEXICON = {
    "राम", "वन", "गच्छति", "गुरु", "इन्द्र", "तत्", "अपि",
    "धर्म", "क्षेत्र", "कुरु", "क्षेत्रे"
}

# --- Basic Reverse Sandhi Rules ---
REVERSE_SANDHI_RULES = [
    ("ा", ["अ+अ"]),    # ā → a + a
    ("े", ["अ+इ", "अ+ई"]),  # e → a+i or a+ī
    ("ो", ["अ+उ", "अ+ऊ"]),  # o → a+u or a+ū
    ("ः", ["ः+"]),          # visarga restoration
]

def generate_candidates(word):
    candidates = []
    for i in range(1, len(word)):
        left, right = word[:i], word[i:]
        # Direct split
        if left in LEXICON and right in LEXICON:
            candidates.append((left, right))
        # Apply reverse sandhi substitutions
        for ch, expansions in REVERSE_SANDHI_RULES:
            if left.endswith(ch):
                for exp in expansions:
                    l_base = left[:-1] + exp.split("+")[0]
                    r_base = exp.split("+")[1] + right
                    if l_base in LEXICON and r_base in LEXICON:
                        candidates.append((l_base, r_base))
    # Deduplicate
    candidates = list(set(candidates))
    return candidates or [("No plausible split found", "")]

def sandhi_splitter(word):
    candidates = generate_candidates(word.strip())
    formatted = [" + ".join(c) for c in candidates]
    return "\n".join(formatted)

with gr.Blocks() as demo:
    gr.Markdown("## Sanskrit Sandhi-Splitter (Prototype)")
    gr.Markdown("Enter a Sanskrit compound word (Devanagari) to see possible splits.")
    inp = gr.Textbox(label="Compound Word (e.g. धर्मक्षेत्रे)")
    out = gr.Textbox(label="Candidate Splits")
    btn = gr.Button("Split Sandhi")
    btn.click(fn=sandhi_splitter, inputs=inp, outputs=out)

if __name__ == "__main__":
    demo.launch()