/**
 * app.js — GharScan frontend logic
 *
 * Uses @gradio/client to connect to the gr.Server backend.
 * Handles: camera capture, image upload, API call, report rendering.
 */

import { Client, handle_file } from
  "https://cdn.jsdelivr.net/npm/@gradio/client@1.5.0/dist/index.min.js";

// ── State ──────────────────────────────────────────────────────────────────────
let selectedFile  = null;
let selectedLang  = "en";
let gradioClient  = null;

const SEVERITY_COLORS = {
  1: "#22c55e",
  2: "#84cc16",
  3: "#f59e0b",
  4: "#ef4444",
  5: "#991b1b",
};

// ── Gradio client init (lazy, connects on first analysis) ─────────────────────
async function getClient() {
  if (!gradioClient) {
    gradioClient = await Client.connect(window.location.origin);
  }
  return gradioClient;
}

// ── Language toggle ────────────────────────────────────────────────────────────
window.setLang = function(lang) {
  selectedLang = lang;
  document.querySelectorAll(".lang-btn").forEach(btn => {
    btn.classList.toggle("active", btn.dataset.lang === lang);
  });
};

// ── Image input handlers ───────────────────────────────────────────────────────
function bindInputs() {
  document.getElementById("cameraInput").addEventListener("change", handleFileChange);
  document.getElementById("uploadInput").addEventListener("change", handleFileChange);

  // Drag-and-drop on capture card
  const dropZone = document.getElementById("dropZone");
  dropZone.addEventListener("dragover", e => { e.preventDefault(); dropZone.style.borderColor = "#3b82f6"; });
  dropZone.addEventListener("dragleave", () => { dropZone.style.borderColor = ""; });
  dropZone.addEventListener("drop", e => {
    e.preventDefault();
    dropZone.style.borderColor = "";
    const file = e.dataTransfer.files[0];
    if (file && file.type.startsWith("image/")) setSelectedFile(file);
  });
}

function handleFileChange(e) {
  const file = e.target.files[0];
  if (file) setSelectedFile(file);
}

function setSelectedFile(file) {
  selectedFile = file;

  // Show preview
  const reader = new FileReader();
  reader.onload = ev => {
    const img = document.getElementById("previewImg");
    img.src = ev.target.result;
    img.classList.remove("hidden");
    document.getElementById("capturePlaceholder").classList.add("hidden");
  };
  reader.readAsDataURL(file);

  // Enable analyse button
  document.getElementById("analyzeBtn").disabled = false;
}

// ── Main analysis flow ─────────────────────────────────────────────────────────
window.runAnalysis = async function() {
  if (!selectedFile) return;

  showLoading();

  try {
    const client = await getClient();

    // Simulate step progression in loading UI
    progressLoadingSteps();

    const result = await client.predict("/analyze_defect", {
      image_path: handle_file(selectedFile),
      language:   selectedLang,
    });

    const report = result.data[0];   // API returns dict as first element

    if (report.analysis_ok === false) {
      showError(report.description || "Analysis failed. Please retake the photo.");
    } else {
      renderReport(report);
    }

  } catch (err) {
    console.error("GharScan API error:", err);
    // Cold-start timeout is common on ZeroGPU — show friendly message
    const msg = err.message?.includes("timeout")
      ? "The model is warming up (first request takes ~30s). Please try again in a moment."
      : `Analysis failed: ${err.message}`;
    showError(msg);
  }
};

// ── Report rendering ───────────────────────────────────────────────────────────
function renderReport(r) {
  // ── Structural banners ──
  const structBanner = document.getElementById("structuralBanner");
  const safeBanner   = document.getElementById("safeBanner");
  if (r.is_structural) {
    structBanner.classList.remove("hidden");
    safeBanner.classList.add("hidden");
    document.getElementById("structuralReasoning").textContent = r.structural_reasoning || "";
  } else {
    safeBanner.classList.remove("hidden");
    structBanner.classList.add("hidden");
  }

  // ── Defect label ──
  document.getElementById("defectLabel").textContent    = r.defect_display || r.defect_type;
  document.getElementById("defectTypeSub").textContent  = r.defect_type?.replace(/_/g, " ").toUpperCase();

  // ── Severity chip ──
  const chip = document.getElementById("severityChip");
  const color = SEVERITY_COLORS[r.severity] || "#6b7280";
  chip.style.borderColor = color;
  document.getElementById("severityNum").textContent   = r.severity;
  document.getElementById("severityNum").style.color   = color;
  document.getElementById("severityWord").textContent  = r.severity_label || "";

  // ── Severity meter animation ──
  const fill   = document.getElementById("severityFill");
  const pct    = ((r.severity / 5) * 100).toFixed(1);
  fill.style.width      = pct + "%";
  fill.style.background = color;

  // ── Text rows ──
  document.getElementById("defectDescription").textContent = r.description     || "";
  document.getElementById("primaryCause").textContent      = r.primary_cause   || "";
  document.getElementById("immediateAction").textContent   = r.immediate_action || "";
  document.getElementById("urgencyDisplay").textContent    = r.urgency_display  || "";

  // ── Cost block ──
  const costRange = document.getElementById("costRange");
  // Strip the leading ₹ if present (it's already in the HTML)
  costRange.textContent = (r.cost_range_inr || "").replace(/^₹\s*/, "");
  document.getElementById("professionalDisplay").textContent = r.professional_display || "";

  // ── Monsoon risk ──
  document.getElementById("monsoonWarning").classList.toggle("hidden", !r.monsoon_risk);

  // ── Liability banner — ALWAYS shown for severity >= 4 (Watch-Out 2) ──
  const liabBanner = document.getElementById("liabilityBanner");
  if (r.show_liability_banner && r.liability_text) {
    document.getElementById("liabilityText").textContent = r.liability_text;
    liabBanner.classList.remove("hidden");
  } else {
    liabBanner.classList.add("hidden");
  }

  // ── Defect-specific disclaimer ──
  const discCard = document.getElementById("disclaimerCard");
  if (r.disclaimer) {
    document.getElementById("disclaimerText").textContent = r.disclaimer;
    discCard.classList.remove("hidden");
  } else {
    discCard.classList.add("hidden");
  }

  showSection("reportSection");
}

// ── UI state helpers ───────────────────────────────────────────────────────────
function showLoading() {
  showSection("loadingSection");
  // Reset step states
  ["step1","step2","step3"].forEach(id => {
    const el = document.getElementById(id);
    el.classList.remove("active","done");
  });
  document.getElementById("step1").classList.add("active");
}

function progressLoadingSteps() {
  const steps = ["step1","step2","step3"];
  let i = 0;
  const interval = setInterval(() => {
    if (i > 0) document.getElementById(steps[i-1]).classList.replace("active","done");
    if (i < steps.length) {
      document.getElementById(steps[i]).classList.add("active");
      const labels = [
        "Step 1 of 3: Classifying defect type",
        "Step 2 of 3: Assessing severity",
        "Step 3 of 3: Calculating cost estimate",
      ];
      document.getElementById("loadingSub").textContent = labels[i];
    }
    i++;
    if (i >= steps.length + 1) clearInterval(interval);
  }, 4000);    // Advance every 4s (inference ~12-15s total)
}

function showError(msg) {
  document.getElementById("errorMsg").textContent = msg;
  showSection("errorSection");
}

function showSection(id) {
  ["captureSection","loadingSection","reportSection","errorSection"].forEach(s => {
    document.getElementById(s)?.classList.toggle("hidden", s !== id);
  });
}

window.resetToCapture = function() {
  selectedFile = null;
  document.getElementById("previewImg").src = "";
  document.getElementById("previewImg").classList.add("hidden");
  document.getElementById("capturePlaceholder").classList.remove("hidden");
  document.getElementById("analyzeBtn").disabled = true;
  document.getElementById("cameraInput").value = "";
  document.getElementById("uploadInput").value = "";
  showSection("captureSection");
};

// ── Boot ───────────────────────────────────────────────────────────────────────
document.addEventListener("DOMContentLoaded", () => {
  bindInputs();

  // Warm up the Gradio client connection early (reduces first-click latency)
  getClient().catch(() => {});
});