import gradio as gr
from similarity import compute_similarity
from custom_css import CUSTOM_CSS_FOR_INTERFACE
from default_values import DEFAULT_DOCUMENTS, DEFAULT_QUESTION


def build_interface():
    """Build and return the Gradio interface"""
    with gr.Blocks(css=CUSTOM_CSS_FOR_INTERFACE, theme=gr.themes.Soft()) as demo:
        with gr.Column(elem_id="title"):
            gr.HTML("<h1>🔍 Smart Medical Search</h1>")
            gr.HTML("<h2> Ask questions, get instant answers from your documents</h2>")

        with gr.Row():
            with gr.Column(scale=1):
                with gr.Group(elem_classes="input-section"):
                    reference_input = gr.Textbox(
                        label="📌 Enter your question about your medical documents:",
                        placeholder="Enter your question here...",
                        value=DEFAULT_QUESTION,
                        lines=3,
                        max_lines=5
                    )

                    gr.HTML("""<h3> 🔍  Your medical documents:</h3>""")

                    comparison_container = gr.Column()

                    with comparison_container:
                        comparison_inputs = []
                        for i in range(15):
                            value = DEFAULT_DOCUMENTS[i] if i < len(DEFAULT_DOCUMENTS) else ""
                            comparison_box = gr.Textbox(
                                label=f"Sentence {i + 1}",
                                placeholder="Enter a document to search...",
                                value=value,
                                lines=2,
                                elem_classes="comparison-box",
                                visible=True if i < 5 else False
                            )
                            comparison_inputs.append(comparison_box)


                    add_btn = gr.Button("➕ Add another document", elem_classes="add-btn", size="md")

                    visible_count = gr.State(5)

                    add_btn.click(
                        fn=_add_comparison_box,
                        inputs=[visible_count],
                        outputs=[visible_count] + comparison_inputs
                    )

                submit_btn = gr.Button("Search for the answer in your documents", variant="primary", elem_id="calc-btn", size="lg")

            with gr.Column(scale=1):
                output = gr.HTML(label="Similarity Scores")

        submit_btn.click(
            fn=compute_similarity,
            inputs=[reference_input] + comparison_inputs,
            outputs=output
        )

    return demo


def _add_comparison_box(count: int) -> list[int]:
    """Check whether new boxes can be added."""
    if count < 15:
        new_count = count + 1
        visibility = [gr.update(visible=True) if i < new_count else gr.update(visible=False)
                      for i in range(15)]
        return [new_count] + visibility
    else:
        return [count] + [gr.update() for _ in range(15)]