from __future__ import annotations

import json

import gradio as gr
import pandas as pd
from PIL import Image

from src import config
from src.data.gallery_store import DemoGallery
from src.pipeline.image_pipeline import ImagePipeline
from src.protocol.fpsi_adapter import FuzzyPSIAdapter


gallery = DemoGallery()
image_pipeline = ImagePipeline()
adapter = FuzzyPSIAdapter(config.DEFAULT_MODE)

CSS = """
footer, .built-with, a[href*="gradio.app"] { display: none !important; }
.main-title { text-align: center; padding: 10px 0 6px; }
.main-title h1 { font-size: 1.7em; margin: 0; letter-spacing: -0.5px; }
.main-title p { color: #555; margin: 2px 0 0; font-size: 0.92em; }
.compact-note textarea { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.small-copy { color: #666; font-size: 0.9em; }
"""


def _example_paths() -> list[list[str]]:
    return [[path] for _, path in gallery.example_choices()]


def _empty_metrics() -> pd.DataFrame:
    return pd.DataFrame(columns=["Metric", "Value"])


def _source_label(match_source: str) -> str:
    if match_source == "enrolled":
        return "Enrolled runtime library"
    return "Packaged LFW gallery"


def _gallery_metrics(summary_json: str, notes: str) -> tuple[str, pd.DataFrame, str, str]:
    payload = json.loads(summary_json)
    summary = payload["summary"]
    match = payload["match"]
    details = payload["details"]
    source_label = _source_label(details.get("match_source", "demo"))

    verdict = (
        f"MATCH: {match['person']}\n"
        f"Source: {source_label} | Distance: {match['hamming_distance']} | Score: {match['score']:.4f}"
        if match["matched"]
        else f"NO MATCH\nBest: {match['person']} | Source: {source_label} | Distance: {match['hamming_distance']} | Score: {match['score']:.4f}"
    )

    metrics_df = pd.DataFrame(
        [
            ("Result source", source_label),
            ("Mode", summary["mode"]),
            ("Dimension", summary["dim"]),
            ("Threshold δ", summary["delta"]),
            ("E-LSH L", summary["L"]),
            ("Latency (s)", f"{summary['time_s']:.3f}"),
            ("Communication (MB)", f"{summary['communication_mb']:.3f}"),
            ("Gallery images", str(summary["gallery_size"])),
            ("Gao feasible", "YES" if summary["gao_feasible"] else "NO"),
            ("Top-5 distances", ", ".join(map(str, details["top5_distances"]))),
        ],
        columns=["Metric", "Value"],
    )

    compact_stats = (
        f"src={details.get('match_source', 'demo')} | mode={summary['mode']} | d={summary['dim']} | "
        f"δ={summary['delta']} | L={summary['L']} | latency={summary['time_s']:.3f}s"
    )

    return verdict, metrics_df, compact_stats, notes


def _query_gallery(query_embedding, features, people, filenames, dim: int):
    if len(people) == 0:
        return None
    return adapter.query_against_gallery(
        query_embedding,
        features,
        people,
        filenames,
        dim,
        calibration_features=gallery.calibration_features,
        calibration_people=gallery.calibration_people,
    )


def _match_from_image(image: Image.Image, dim: int, mode: str):
    adapter.mode = mode
    analysis = image_pipeline.analyze(image)

    checked_enrolled = gallery.has_enrollments()
    enrolled_result = None
    if checked_enrolled:
        enrolled_result = _query_gallery(
            analysis.embedding,
            gallery.enrolled_features,
            gallery.enrolled_people,
            gallery.enrolled_filenames,
            dim,
        )

    if enrolled_result is not None and enrolled_result[0].matched:
        match, summary, details = enrolled_result
        details["match_source"] = "enrolled"
        notes_prefix = "matched enrolled-user overlay"
    else:
        match, summary, details = _query_gallery(
            analysis.embedding,
            gallery.features,
            gallery.people,
            gallery.filenames,
            dim,
        )
        details["match_source"] = "demo"
        if checked_enrolled:
            notes_prefix = "no enrolled-user match; used packaged LFW gallery"
        else:
            notes_prefix = "no enrolled users registered; used packaged LFW gallery"

    details["checked_enrolled"] = checked_enrolled
    details["enrolled_gallery_size"] = int(len(gallery.enrolled_people))
    gallery_image = Image.open(gallery.gallery_image_path(match.filename, match.person)).convert("RGB")
    summary_json = adapter.export_summary(match, summary, details)
    notes = "\n".join(f"- {note}" for note in ([notes_prefix] + analysis.notes + summary.notes))
    verdict, metrics_df, compact_stats, note_text = _gallery_metrics(summary_json, notes)
    return analysis.preview, gallery_image, verdict, compact_stats, metrics_df, note_text, summary_json


def run_image_demo(image: Image.Image, dim: int, mode: str):
    if image is None:
        raise gr.Error("Please upload or capture a face image.")
    return _match_from_image(image, dim, mode)


def run_realtime_demo(image: Image.Image | None, dim: int, mode: str):
    if image is None:
        return None, None, "Waiting for webcam frame.", "", _empty_metrics(), "", ""
    try:
        return _match_from_image(image, dim, mode)
    except Exception as exc:
        return None, None, f"Realtime error: {exc}", "", _empty_metrics(), "", ""


def register_person(image: Image.Image | None, person: str):
    if image is None:
        raise gr.Error("Please upload or capture a face image.")

    normalized_name = " ".join((person or "").split())
    if not normalized_name:
        raise gr.Error("Please enter a name before registering.")

    analysis = image_pipeline.analyze(image)
    record, replaced = gallery.enroll(normalized_name, analysis.preview, analysis.embedding)
    saved_image = Image.open(record.gallery_path).convert("RGB")
    status = (
        f"Updated {normalized_name} in the shared temporary database."
        if replaced
        else f"Registered {normalized_name} in the shared temporary database."
    )
    details = (
        "Upload and Realtime queries will search enrolled users first. "
        "This shared temporary database may reset when the Space restarts."
    )
    return analysis.preview, saved_image, status, details, gallery.gallery_items(1), gallery.database_info(1), 1


def load_gallery_page(page: float | int | None):
    page_num = 1 if page is None else int(page)
    return gallery.gallery_items(page_num), gallery.database_info(page_num)


def build_app() -> gr.Blocks:
    summary = gallery.summary()
    with gr.Blocks(title=config.SPACE_TITLE, theme=gr.themes.Base(), css=CSS) as demo:
        gr.HTML(
            f'<div class="main-title"><h1>{config.SPACE_TITLE}</h1><p>{config.SPACE_SUBTITLE}</p></div>'
        )

        with gr.Tabs():
            with gr.Tab("Database"):
                with gr.Row():
                    with gr.Column(scale=4):
                        database_gallery = gr.Gallery(
                            value=gallery.gallery_items(1),
                            label="Visible Gallery",
                            columns=4,
                            rows=4,
                            height=520,
                            object_fit="cover",
                            preview=True,
                            allow_preview=True,
                        )
                    with gr.Column(scale=1):
                        database_info = gr.Textbox(
                            value=gallery.database_info(1),
                            label="Info",
                            interactive=False,
                            lines=4,
                        )
                        gallery_page = gr.Number(label="Page", value=1, minimum=1, maximum=gallery.total_pages(), precision=0)
                        load_page_btn = gr.Button("Load")
                        with gr.Accordion("Parameters", open=False):
                            gr.Dataframe(
                                headers=["Param", "Value"],
                                value=[
                                    ["Backend", config.DEFAULT_MODE],
                                    ["Dimensions", ", ".join(map(str, config.DEFAULT_DIMENSIONS))],
                                    ["Matching images", str(summary["gallery_size"])],
                                    ["Matching identities", str(summary["identity_count"])],
                                    ["Enrolled images", str(summary["enrolled_gallery_size"])],
                                    ["Enrolled identities", str(summary["enrolled_identity_count"])],
                                    ["Visible thumbnails", str(summary["visible_gallery_size"])],
                                    ["Calibration", str(summary["calibration_size"])],
                                    ["Embedding dim", str(summary["dimensions"])],
                                ],
                                interactive=False,
                            )
                load_page_btn.click(load_gallery_page, inputs=[gallery_page], outputs=[database_gallery, database_info], api_name=False)

            with gr.Tab("Enroll"):
                gr.Markdown("Register a face with a name into the shared temporary database. Later Upload and Realtime queries will search this registered library first.")
                with gr.Row():
                    with gr.Column():
                        enroll_image = gr.Image(
                            label="Registration Face",
                            type="pil",
                            sources=["upload", "webcam"],
                            height=280,
                        )
                        enroll_name = gr.Textbox(label="Name", placeholder="Enter the identity name to register")
                        enroll_btn = gr.Button("Register Face", variant="primary")
                    with gr.Column():
                        enroll_saved = gr.Image(label="Saved Database Face", height=280, interactive=False)
                        enroll_status = gr.Textbox(label="Registration Status", lines=2, interactive=False)
                with gr.Row():
                    with gr.Column():
                        enroll_preview = gr.Image(label="Processed Registration Face", height=220, interactive=False)
                    with gr.Column():
                        enroll_notes = gr.Textbox(label="Notes", lines=4, interactive=False)

                enroll_btn.click(
                    register_person,
                    inputs=[enroll_image, enroll_name],
                    outputs=[enroll_preview, enroll_saved, enroll_status, enroll_notes, database_gallery, database_info, gallery_page],
                    api_name=False,
                )

            with gr.Tab("Upload"):
                gr.Markdown("Upload a query face and match it against the enrolled-user overlay first, then the larger LFW-derived database.")
                with gr.Row():
                    with gr.Column():
                        image_input = gr.Image(
                            label="Query Face",
                            type="pil",
                            sources=["upload", "webcam"],
                            height=280,
                        )
                        gr.Examples(examples=_example_paths(), inputs=[image_input], label="Examples")
                        with gr.Accordion("Advanced Settings", open=False):
                            upload_dim = gr.Dropdown(
                                choices=list(config.DEFAULT_DIMENSIONS),
                                value=config.DEFAULT_DIM,
                                label="Binary dimension",
                            )
                            upload_mode = gr.Dropdown(
                                choices=list(config.SUPPORTED_MODES),
                                value=config.DEFAULT_MODE,
                                label="Backend mode",
                            )
                        upload_btn = gr.Button("Run Identification", variant="primary")
                    with gr.Column():
                        upload_match = gr.Image(label="Matched Identity", height=280, interactive=False)
                        upload_verdict = gr.Textbox(label="Verdict", lines=3, interactive=False)
                        upload_summary = gr.Textbox(label="Summary", lines=2, interactive=False)

                with gr.Row():
                    with gr.Column():
                        upload_preview = gr.Image(label="Processed Query", height=220, interactive=False)
                    with gr.Column():
                        upload_metrics = gr.Dataframe(label="Protocol Metrics", interactive=False)

                with gr.Accordion("Execution Notes", open=False):
                    upload_notes = gr.Textbox(label="Notes", lines=6, interactive=False, elem_classes=["compact-note"])
                with gr.Accordion("Detailed JSON Summary", open=False):
                    upload_json = gr.Textbox(label="JSON", lines=14, interactive=False, elem_classes=["compact-note"])

                upload_btn.click(
                    run_image_demo,
                    inputs=[image_input, upload_dim, upload_mode],
                    outputs=[upload_preview, upload_match, upload_verdict, upload_summary, upload_metrics, upload_notes, upload_json],
                    api_name=False,
                )

            with gr.Tab("Realtime"):
                gr.Markdown("Browser webcam recognition. Frames are processed on a throttled interval for stability.")
                with gr.Row():
                    with gr.Column():
                        webcam_input = gr.Image(
                            label="Realtime Camera",
                            type="pil",
                            sources=["webcam"],
                            streaming=True,
                            height=280,
                        )
                        gr.Markdown(
                            f"<div class='small-copy'>Auto-matches every {config.REALTIME_STREAM_SECONDS:.1f}s while frames are available.</div>"
                        )
                        with gr.Accordion("Advanced Settings", open=False):
                            realtime_dim = gr.Dropdown(
                                choices=list(config.DEFAULT_DIMENSIONS),
                                value=config.DEFAULT_DIM,
                                label="Binary dimension",
                            )
                            realtime_mode = gr.Dropdown(
                                choices=list(config.SUPPORTED_MODES),
                                value=config.DEFAULT_MODE,
                                label="Backend mode",
                            )
                        realtime_btn = gr.Button("Identify Current Frame")
                    with gr.Column():
                        realtime_match = gr.Image(label="Matched Identity", height=280, interactive=False)
                        realtime_verdict = gr.Textbox(label="Realtime Verdict", lines=3, interactive=False)
                        realtime_summary = gr.Textbox(label="Realtime Summary", lines=2, interactive=False)

                with gr.Row():
                    with gr.Column():
                        realtime_preview = gr.Image(label="Current Frame Preview", height=220, interactive=False)
                    with gr.Column():
                        realtime_metrics = gr.Dataframe(label="Realtime Metrics", interactive=False)

                with gr.Accordion("Realtime Notes", open=False):
                    realtime_notes = gr.Textbox(label="Notes", lines=6, interactive=False, elem_classes=["compact-note"])
                with gr.Accordion("Realtime JSON Summary", open=False):
                    realtime_json = gr.Textbox(label="JSON", lines=14, interactive=False, elem_classes=["compact-note"])

                webcam_input.stream(
                    run_realtime_demo,
                    inputs=[webcam_input, realtime_dim, realtime_mode],
                    outputs=[realtime_preview, realtime_match, realtime_verdict, realtime_summary, realtime_metrics, realtime_notes, realtime_json],
                    api_name=False,
                    trigger_mode="always_last",
                    concurrency_limit=1,
                    show_progress="hidden",
                    stream_every=config.REALTIME_STREAM_SECONDS,
                )
                realtime_btn.click(
                    run_realtime_demo,
                    inputs=[webcam_input, realtime_dim, realtime_mode],
                    outputs=[realtime_preview, realtime_match, realtime_verdict, realtime_summary, realtime_metrics, realtime_notes, realtime_json],
                    api_name=False,
                )

        with gr.Accordion("Protocol Details", open=False):
            gr.Markdown(
                f"""
**Pipeline**: image/webcam frame → face embedding → binary projection → enrolled-user overlay match → fallback LFW E-LSH/Hamming verification.

**Modes**: `simulation` for public reliability, `full` for optional native FPSI execution when runtime support is present.

**Database**: {summary['demo_gallery_size']} packaged LFW images plus a shared temporary enrolled-user overlay are used for matching and browsing.
                """
            )

        return demo