"""UWColorKit demo: zero-shot underwater color recovery from location + depth."""

import json
import os

import gradio as gr

import client
import color
import exif_gps

DEFAULT_LAT, DEFAULT_LNG, DEFAULT_DEPTH = 20.21, -87.43, 12

RAW_EXTENSIONS = [
    ".dng", ".cr2", ".cr3", ".arw", ".arq", ".nef", ".nrw", ".raf", ".rw2",
    ".orf", ".pef", ".srw", ".sr2", ".raw", ".rwl", ".dcr", ".kdc", ".3fr",
    ".mef", ".mos", ".iiq", ".erf", ".x3f",
]

MAP_HTML = (
    '<div id="scubai-map" style="height:360px;border-radius:8px;'
    'overflow:hidden;margin:6px 0;border:1px solid #ddd;"></div>'
)

LEAFLET_JS = """
() => {
  const CSS = "https://unpkg.com/leaflet@1.9.4/dist/leaflet.css";
  const JS  = "https://unpkg.com/leaflet@1.9.4/dist/leaflet.js";
  function setNumber(id, v) {
    const el = document.getElementById(id);
    const inp = el ? el.querySelector("input") : null;
    if (!inp) return;
    const set = Object.getOwnPropertyDescriptor(window.HTMLInputElement.prototype, "value").set;
    set.call(inp, v);
    inp.dispatchEvent(new Event("input", { bubbles: true }));
  }
  function readNumber(id, fb) {
    const el = document.getElementById(id);
    const inp = el ? el.querySelector("input") : null;
    const v = inp ? parseFloat(inp.value) : NaN;
    return isNaN(v) ? fb : v;
  }
  function initMap() {
    const el = document.getElementById("scubai-map");
    if (!el || !window.L) { setTimeout(initMap, 200); return; }
    if (el.dataset.ready === "1") return;
    el.dataset.ready = "1";
    const map = L.map(el).setView([readNumber("scubai_lat", 20.21), readNumber("scubai_lng", -87.43)], 5);
    L.tileLayer("https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
                { maxZoom: 19, attribution: "© OpenStreetMap" }).addTo(map);
    const marker = L.marker(map.getCenter(), { draggable: true }).addTo(map);
    function publish(ll) {
      setNumber("scubai_lat", Math.round(ll.lat * 1e6) / 1e6);
      setNumber("scubai_lng", Math.round(ll.lng * 1e6) / 1e6);
    }
    map.on("click", (e) => { marker.setLatLng(e.latlng); publish(e.latlng); });
    marker.on("dragend", () => publish(marker.getLatLng()));
    window.scubaiSetPin = (la, ln) => {
      la = parseFloat(la); ln = parseFloat(ln);
      if (!isNaN(la) && !isNaN(ln)) { marker.setLatLng([la, ln]); map.panTo([la, ln]); }
    };
    setTimeout(() => map.invalidateSize(), 300);
  }
  function ensure() {
    if (!document.querySelector('link[data-scubai]')) {
      const l = document.createElement("link");
      l.rel = "stylesheet"; l.href = CSS; l.setAttribute("data-scubai", "1");
      document.head.appendChild(l);
    }
    if (window.L) return initMap();
    let s = document.querySelector('script[data-scubai]');
    if (!s) {
      s = document.createElement("script");
      s.src = JS; s.async = true; s.setAttribute("data-scubai", "1");
      s.onload = initMap; document.head.appendChild(s);
    } else { s.addEventListener("load", initMap); }
  }
  ensure();
}
"""

MOVE_PIN_JS = "(la, ln) => { if (window.scubaiSetPin) window.scubaiSetPin(la, ln); }"

APP_STORE_URL = "https://apps.apple.com/us/app/scubai/id6741768984"
SITE_URL = "https://scub.ai"

HEADER_MD = """
# 🤿 UWColorKit — zero-shot underwater white balance
The color engine inside **ScubAI** — it brings back the reds and oranges the water strips away.
"""

LIGHTING_NOTE_MD = (
    "> ☀️ **Ambient light only.** This demo reverses how *sunlight* fades with depth, so "
    "strobe, torch, or mixed light will over-correct. The full **ScubAI** app handles those "
    "— this is just the bare engine."
)

APP_CTA_MD = (
    f"🐠 Shooting underwater on an iPhone? **[ScubAI]({APP_STORE_URL})** "
    "does this automatically, every dive."
)

FOOTER_MD = (
    "*Your RAW is decoded for this preview and discarded right after.*\n\n"
    f"*UWColorKit · patent-pending underwater color engine · [scub.ai]({SITE_URL})*"
)

EXAMPLES_DIR = os.path.join(os.path.dirname(__file__), "examples")


def load_examples():
    """Read examples/examples.json -> ([[file, lat, lng, depth], ...], [label, ...]).

    GPS lives in each RAW's EXIF, not the manifest, so the sample dives stay in
    sync with the photo and the JSON only carries file + depth (+ optional label).
    Coordinates come from the same exif_gps path the upload handler uses; a file
    without GPS EXIF falls back to the default location (logged).
    """
    manifest = os.path.join(EXAMPLES_DIR, "examples.json")
    if not os.path.exists(manifest):
        return [], []
    try:
        with open(manifest) as fh:
            entries = json.load(fh)
    except (OSError, ValueError) as exc:
        print(f"[uwcolorkit] examples.json could not be parsed: {exc}")
        return [], []
    rows, labels, missing = [], [], 0
    for e in entries:
        filename = e.get("file", "")
        path = os.path.join(EXAMPLES_DIR, filename)
        if not os.path.exists(path):
            missing += 1
            continue
        gps = exif_gps.extract_gps(path)
        if gps is None:
            print(f"[uwcolorkit] {filename!r}: no GPS in EXIF, using default location")
            lat, lng = DEFAULT_LAT, DEFAULT_LNG
        else:
            lat, lng = gps
        rows.append([path, round(lat, 6), round(lng, 6), e.get("depth", DEFAULT_DEPTH)])
        labels.append(e.get("label") or os.path.splitext(filename)[0])
    if missing:
        print(f"[uwcolorkit] {missing} example(s) listed in examples.json have no file yet")
    return rows, labels


def _discard(path):
    try:
        if path and os.path.exists(path):
            os.remove(path)
    except OSError:
        pass


# Raw object (+ month) per upload, RAM only. Lets the user re-run with a different
# depth without re-reading the file (which we discard right after opening).
_DECODE_CACHE = {}
_DECODE_CACHE_MAX = 6


def _cache_put(path, value):
    _DECODE_CACHE[path] = value
    while len(_DECODE_CACHE) > _DECODE_CACHE_MAX:
        old = _DECODE_CACHE.pop(next(iter(_DECODE_CACHE)))
        try:
            old[0].close()  # free the evicted RawPy's buffers
        except Exception:
            pass


def on_upload(path):
    gps = exif_gps.extract_gps(path) if path else None
    if gps:
        return gr.update(value=round(gps[0], 6)), gr.update(value=round(gps[1], 6))
    return gr.update(), gr.update()


def correct(path, lat, lng, depth):
    if not path:
        raise gr.Error("Upload a RAW file first.")
    if lat is None or lng is None:
        raise gr.Error("Set a location on the map.")

    # imread once per upload, cache the raw object, then discard the file. Re-runs
    # (e.g. a new depth) re-render from the in-memory raw — no second file read.
    cached = _DECODE_CACHE.get(path)
    if cached is None:
        if not os.path.exists(path):
            raise gr.Error("Please re-upload the RAW — the previous file was cleared.")
        month = exif_gps.extract_month(path)  # read metadata before discarding
        try:
            raw = color.open_raw(path)
        except Exception as exc:
            raise gr.Error(f"Could not decode RAW ({type(exc).__name__}): {exc}")
        finally:
            _discard(path)
        cached = (raw, month)
        _cache_put(path, cached)
    raw, month = cached  # month is None when no EXIF date -> engine uses yearly data

    try:
        illum = client.fetch_illuminant(lat, lng, depth, month)
    except Exception as exc:
        raise gr.Error(f"Parameter API error: {exc}")

    print(f"[uwcolorkit] month={month} stub={client.using_stub()}")
    before = color.render(raw, color.baseline_wb(raw))
    after = color.render(raw, color.wb_from_chromaticity(raw, illum.as_tuple()))
    return (before, after)


def build():
    with gr.Blocks(title="UWColorKit — underwater color engine", theme=gr.themes.Soft()) as demo:
        gr.Markdown(HEADER_MD)
        with gr.Row():
            with gr.Column():
                raw_file = gr.File(
                    label="RAW photo",
                    file_count="single",
                    type="filepath",
                    file_types=RAW_EXTENSIONS,
                )
                gr.Markdown(LIGHTING_NOTE_MD)
                gr.HTML(MAP_HTML)
                with gr.Row():
                    lat = gr.Number(label="Latitude", value=DEFAULT_LAT, elem_id="scubai_lat", precision=6)
                    lng = gr.Number(label="Longitude", value=DEFAULT_LNG, elem_id="scubai_lng", precision=6)
                depth = gr.Slider(0, 40, value=DEFAULT_DEPTH, step=1, label="Depth (m)")
                correct_btn = gr.Button("Correct color", variant="primary")
                examples, example_labels = load_examples()
                if examples:
                    gr.Examples(
                        examples=examples,
                        inputs=[raw_file, lat, lng, depth],
                        label="Or try a sample dive",
                        example_labels=example_labels,
                    )
            with gr.Column():
                slider = gr.ImageSlider(label="RAW → Corrected", type="numpy", slider_position=50)

        gr.Markdown(APP_CTA_MD)
        gr.Markdown(FOOTER_MD)

        raw_file.upload(on_upload, inputs=raw_file, outputs=[lat, lng])
        correct_btn.click(correct, inputs=[raw_file, lat, lng, depth], outputs=slider)
        lat.change(None, [lat, lng], None, js=MOVE_PIN_JS)
        lng.change(None, [lat, lng], None, js=MOVE_PIN_JS)
        demo.load(None, None, None, js=LEAFLET_JS)
    return demo


demo = build()

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