import { SOCIAL_MEDIA_PRESETS } from "@snapotter/shared";
import { Download, Info } from "lucide-react";
import { useCallback, useEffect, useRef, useState } from "react";
import { ProgressCard } from "@/components/common/progress-card";
import { useTranslation } from "@/contexts/i18n-context";
import { useToolProcessor } from "@/hooks/use-tool-processor";
import { largestRatioBox, pairedDimension, RESIZE_RATIO_PRESETS } from "@/lib/aspect-ratio";
import { format } from "@/lib/format";
import { useFileStore } from "@/stores/file-store";

type ResizeTab = "presets" | "custom" | "scale" | "content-aware";
type FitMode = "cover" | "contain" | "fill";

const FIT_MODES: FitMode[] = ["cover", "contain", "fill"];

// Group presets by platform
const platforms = [...new Set(SOCIAL_MEDIA_PRESETS.map((p) => p.platform))];

function HintIcon({ text }: { text: string }) {
  return (
    <span className="relative group">
      <Info className="h-3 w-3 text-muted-foreground" />
      <span className="pointer-events-none absolute left-1/2 -translate-x-1/2 bottom-full mb-1.5 w-48 rounded bg-foreground px-2 py-1.5 text-[11px] leading-tight text-background opacity-0 transition-opacity group-hover:opacity-100 z-10">
        {text}
      </span>
    </span>
  );
}

export interface ResizeControlsProps {
  settings?: Record<string, unknown>;
  onChange?: (settings: Record<string, unknown>) => void;
}

export function ResizeControls({ settings: initialSettings, onChange }: ResizeControlsProps) {
  const { t } = useTranslation();
  const { currentEntry } = useFileStore();
  const [tab, setTab] = useState<ResizeTab>("custom");
  const [selectedPreset, setSelectedPreset] = useState<string | null>(null);
  const [width, setWidth] = useState<string>("");
  const [height, setHeight] = useState<string>("");
  const [percentage, setPercentage] = useState<string>("50");
  const [fit, setFit] = useState<FitMode>("cover");
  // "free" = independent width/height (default, unchanged behavior). "original" =
  // lock to the source image's ratio. Otherwise a RESIZE_RATIO_PRESETS id (e.g. "16:9").
  const [ratioId, setRatioId] = useState<string>("free");
  const [withoutEnlargement, setWithoutEnlargement] = useState(false);
  const contentAware = tab === "content-aware";
  const [protectFaces, setProtectFaces] = useState(false);
  const [blurRadius, setBlurRadius] = useState(4);
  const [sobelThreshold, setSobelThreshold] = useState(2);
  const [squareMode, setSquareMode] = useState(false);

  const initializedRef = useRef(false);
  useEffect(() => {
    if (!initialSettings || initializedRef.current) return;
    initializedRef.current = true;
    if (initialSettings.width != null) setWidth(String(initialSettings.width));
    if (initialSettings.height != null) setHeight(String(initialSettings.height));
    if (initialSettings.percentage != null) setPercentage(String(initialSettings.percentage));
    if (initialSettings.fit != null) setFit(initialSettings.fit as FitMode);
    if (initialSettings.withoutEnlargement != null)
      setWithoutEnlargement(Boolean(initialSettings.withoutEnlargement));
    if (initialSettings.protectFaces != null)
      setProtectFaces(Boolean(initialSettings.protectFaces));
    if (initialSettings.blurRadius != null) setBlurRadius(Number(initialSettings.blurRadius));
    if (initialSettings.sobelThreshold != null)
      setSobelThreshold(Number(initialSettings.sobelThreshold));
    if (initialSettings.square != null) setSquareMode(Boolean(initialSettings.square));
    if (initialSettings.contentAware) setTab("content-aware");
    else if (initialSettings.percentage != null) setTab("scale");
  }, [initialSettings]);

  const onChangeRef = useRef(onChange);
  useEffect(() => {
    onChangeRef.current = onChange;
  });

  useEffect(() => {
    const settings: Record<string, unknown> = {};
    if (contentAware) {
      settings.contentAware = true;
      if (!squareMode) {
        if (width) settings.width = Number(width);
        if (height) settings.height = Number(height);
      }
      settings.protectFaces = protectFaces;
      settings.blurRadius = blurRadius;
      settings.sobelThreshold = sobelThreshold;
      settings.square = squareMode;
    } else if (tab === "scale") {
      settings.percentage = Number(percentage);
    } else {
      if (width) settings.width = Number(width);
      if (height) settings.height = Number(height);
      settings.fit = tab === "presets" ? "cover" : fit;
      settings.withoutEnlargement = withoutEnlargement;
    }
    onChangeRef.current?.(settings);
  }, [
    tab,
    width,
    height,
    percentage,
    fit,
    withoutEnlargement,
    protectFaces,
    blurRadius,
    sobelThreshold,
    squareMode,
    contentAware,
  ]);

  // Resolve a chip id to a numeric ratio (width / height), or null when it
  // shouldn't lock (Free, or Original before the source dimensions are known).
  const ratioValueFor = (id: string): number | null => {
    if (id === "free") return null;
    if (id === "original") {
      const w = currentEntry?.originalWidth;
      const h = currentEntry?.originalHeight;
      return w && h ? w / h : null;
    }
    return RESIZE_RATIO_PRESETS.find((p) => p.id === id)?.value ?? null;
  };

  // Linking only applies on the Custom tab; the width/height inputs are shared
  // with the Content-Aware tab, which manages its dimensions independently.
  const handleWidthChange = (raw: string) => {
    setWidth(raw);
    if (tab !== "custom") return;
    const r = ratioValueFor(ratioId);
    const n = Number(raw);
    if (r && raw !== "" && Number.isFinite(n) && n > 0) {
      setHeight(String(pairedDimension(n, r, "width")));
    }
  };

  const handleHeightChange = (raw: string) => {
    setHeight(raw);
    if (tab !== "custom") return;
    const r = ratioValueFor(ratioId);
    const n = Number(raw);
    if (r && raw !== "" && Number.isFinite(n) && n > 0) {
      setWidth(String(pairedDimension(n, r, "height")));
    }
  };

  const handleRatioSelect = (id: string) => {
    setRatioId(id);
    const r = ratioValueFor(id);
    if (!r) return;
    const w = Number(width);
    const h = Number(height);
    if (width !== "" && Number.isFinite(w) && w > 0) {
      // Keep the width the user already has, snap height to the ratio.
      setHeight(String(pairedDimension(w, r, "width")));
    } else if (height !== "" && Number.isFinite(h) && h > 0) {
      setWidth(String(pairedDimension(h, r, "height")));
    } else if (currentEntry?.originalWidth && currentEntry?.originalHeight) {
      // Nothing typed yet: prefill the largest box of this ratio that fits.
      const box = largestRatioBox(currentEntry.originalWidth, currentEntry.originalHeight, r);
      setWidth(String(box.width));
      setHeight(String(box.height));
    }
  };

  const handlePreset = (preset: (typeof SOCIAL_MEDIA_PRESETS)[number]) => {
    const key = `${preset.platform}-${preset.name}`;
    if (selectedPreset === key) {
      setSelectedPreset(null);
      setWidth("");
      setHeight("");
    } else {
      setSelectedPreset(key);
      setWidth(String(preset.width));
      setHeight(String(preset.height));
    }
  };

  const tabClass = (t: ResizeTab) =>
    `flex-1 text-xs py-1.5 rounded ${tab === t ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`;

  const ratioChips: { id: string; label: string }[] = [
    { id: "free", label: t.toolSettings.resize.ratioFree },
    { id: "original", label: t.toolSettings.resize.ratioOriginal },
    ...RESIZE_RATIO_PRESETS.map((p) => ({ id: p.id, label: p.id })),
  ];

  const dimensionInputs = (
    <div className="flex items-end gap-2">
      <div className="flex-1">
        <label htmlFor="resize-width" className="text-xs text-muted-foreground">
          {t.toolSettings.resize.widthPx}
        </label>
        <input
          id="resize-width"
          type="number"
          value={width}
          onChange={(e) => handleWidthChange(e.target.value)}
          placeholder="Auto"
          disabled={squareMode && contentAware}
          className="w-full mt-0.5 px-2 py-1.5 rounded border border-border bg-background text-sm text-foreground disabled:opacity-50"
        />
      </div>
      <div className="flex-1">
        <label htmlFor="resize-height" className="text-xs text-muted-foreground">
          {t.toolSettings.resize.heightPx}
        </label>
        <input
          id="resize-height"
          type="number"
          value={height}
          onChange={(e) => handleHeightChange(e.target.value)}
          placeholder="Auto"
          disabled={squareMode && contentAware}
          className="w-full mt-0.5 px-2 py-1.5 rounded border border-border bg-background text-sm text-foreground disabled:opacity-50"
        />
      </div>
    </div>
  );

  const enlargementCheckbox = (
    <label className="flex items-center gap-1.5 text-xs text-foreground">
      <input
        type="checkbox"
        checked={withoutEnlargement}
        onChange={(e) => setWithoutEnlargement(e.target.checked)}
        className="rounded"
      />
      <span>{t.toolSettings.resize.limitToOriginalSize}</span>
      <HintIcon text={t.toolSettings.resize.limitToOriginalSizeHint} />
    </label>
  );

  return (
    <div className="space-y-4">
      {/* Tab selector */}
      <div>
        <div className="flex gap-1">
          <button type="button" onClick={() => setTab("custom")} className={tabClass("custom")}>
            {t.toolSettings.resize.customSize}
          </button>
          <button type="button" onClick={() => setTab("scale")} className={tabClass("scale")}>
            {t.toolSettings.resize.scale}
          </button>
          <button type="button" onClick={() => setTab("presets")} className={tabClass("presets")}>
            {t.toolSettings.resize.presets}
          </button>
          <button
            type="button"
            onClick={() => setTab("content-aware")}
            className={tabClass("content-aware")}
          >
            {t.toolSettings.resize.contentAware}
          </button>
        </div>
      </div>

      {/* Presets tab */}
      {tab === "presets" && (
        <div className="space-y-3 max-h-[50dvh] overflow-y-auto pe-1">
          {platforms.map((platform) => (
            <div key={platform}>
              <p className="text-xs font-medium text-muted-foreground mb-1.5">{platform}</p>
              <div className="space-y-1">
                {SOCIAL_MEDIA_PRESETS.filter((p) => p.platform === platform).map((preset) => {
                  const key = `${preset.platform}-${preset.name}`;
                  const isSelected = selectedPreset === key;
                  return (
                    <button
                      key={key}
                      type="button"
                      onClick={() => handlePreset(preset)}
                      className={`w-full flex items-center justify-between px-2.5 py-1.5 rounded border text-sm transition-colors ${
                        isSelected
                          ? "border-primary bg-primary/10 text-foreground"
                          : "border-border text-muted-foreground hover:border-primary/50 hover:text-foreground"
                      }`}
                    >
                      <span>{preset.name}</span>
                      <span className="text-xs tabular-nums">
                        {preset.width} x {preset.height}
                      </span>
                    </button>
                  );
                })}
              </div>
            </div>
          ))}

          {enlargementCheckbox}
        </div>
      )}

      {/* Custom Size tab */}
      {tab === "custom" && (
        <div className="space-y-3">
          {dimensionInputs}

          {/* Aspect ratio */}
          <div>
            <p className="text-xs text-muted-foreground">{t.toolSettings.resize.aspectRatio}</p>
            <div className="flex flex-wrap gap-1 mt-1">
              {ratioChips.map((chip) => (
                <button
                  key={chip.id}
                  type="button"
                  onClick={() => handleRatioSelect(chip.id)}
                  aria-pressed={ratioId === chip.id}
                  className={`px-2.5 py-1 rounded text-xs ${
                    ratioId === chip.id
                      ? "bg-primary text-primary-foreground"
                      : "bg-muted text-muted-foreground hover:text-foreground"
                  }`}
                >
                  {chip.label}
                </button>
              ))}
            </div>
          </div>

          {/* Fit mode */}
          <div>
            <p className="text-xs text-muted-foreground">{t.toolSettings.resize.fitMode}</p>
            <div className="flex gap-1 mt-1">
              {FIT_MODES.map((f) => (
                <button
                  key={f}
                  type="button"
                  onClick={() => setFit(f)}
                  className={`flex-1 text-xs py-1.5 rounded ${fit === f ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`}
                >
                  {f === "cover"
                    ? t.toolSettings.resize.cropToFit
                    : f === "contain"
                      ? t.toolSettings.resize.fitInside
                      : t.toolSettings.resize.stretch}
                </button>
              ))}
            </div>
          </div>

          {enlargementCheckbox}
        </div>
      )}

      {/* Scale tab */}
      {tab === "scale" && (
        <div className="space-y-3">
          <div>
            <label htmlFor="resize-scale" className="text-xs text-muted-foreground">
              Scale (%)
            </label>
            <input
              id="resize-scale"
              type="number"
              value={percentage}
              onChange={(e) => setPercentage(e.target.value)}
              min={1}
              className="w-full mt-0.5 px-2 py-1.5 rounded border border-border bg-background text-sm text-foreground"
            />
          </div>
          <div className="flex gap-1">
            {[25, 50, 75].map((pct) => (
              <button
                key={pct}
                type="button"
                onClick={() => setPercentage(String(pct))}
                className={`flex-1 text-xs py-1.5 rounded ${
                  percentage === String(pct)
                    ? "bg-primary text-primary-foreground"
                    : "bg-muted text-muted-foreground"
                }`}
              >
                {pct}%
              </button>
            ))}
          </div>
        </div>
      )}

      {/* Content-aware tab */}
      {contentAware && (
        <div className="space-y-3">
          {dimensionInputs}

          {/* Square mode */}
          <label className="flex items-center gap-2 text-xs text-foreground">
            <input
              type="checkbox"
              checked={squareMode}
              onChange={(e) => setSquareMode(e.target.checked)}
              className="rounded"
            />
            {t.toolSettings.resize.resizeToSquare}
          </label>

          {/* Face protection */}
          <label className="flex items-center gap-2 text-xs text-foreground">
            <input
              type="checkbox"
              checked={protectFaces}
              onChange={(e) => setProtectFaces(e.target.checked)}
              className="rounded"
            />
            {t.toolSettings.resize.protectFaces}
          </label>

          {/* Blur radius */}
          <div>
            <div className="flex items-center justify-between">
              <label htmlFor="blur-radius" className="text-xs text-muted-foreground">
                Smoothing
              </label>
              <span className="text-xs tabular-nums text-muted-foreground">{blurRadius}</span>
            </div>
            <input
              id="blur-radius"
              type="range"
              min={0}
              max={20}
              value={blurRadius}
              onChange={(e) => setBlurRadius(Number(e.target.value))}
              className="w-full mt-1 h-1.5 rounded-full appearance-none bg-muted accent-primary"
            />
          </div>

          {/* Sobel threshold */}
          <div>
            <div className="flex items-center justify-between">
              <label htmlFor="sobel-threshold" className="text-xs text-muted-foreground">
                Edge sensitivity
              </label>
              <span className="text-xs tabular-nums text-muted-foreground">{sobelThreshold}</span>
            </div>
            <input
              id="sobel-threshold"
              type="range"
              min={1}
              max={20}
              value={sobelThreshold}
              onChange={(e) => setSobelThreshold(Number(e.target.value))}
              className="w-full mt-1 h-1.5 rounded-full appearance-none bg-muted accent-primary"
            />
          </div>
        </div>
      )}
    </div>
  );
}

export function ResizeSettings() {
  const { t } = useTranslation();
  const { files } = useFileStore();
  const standardResize = useToolProcessor("resize");
  const contentAwareResize = useToolProcessor("content-aware-resize");

  const [settings, setSettings] = useState<Record<string, unknown>>({});
  const [isContentAware, setIsContentAware] = useState(false);

  const handleSettingsChange = useCallback((newSettings: Record<string, unknown>) => {
    setSettings(newSettings);
    setIsContentAware(!!newSettings.contentAware);
  }, []);

  const active = isContentAware ? contentAwareResize : standardResize;
  const { processFiles, processAllFiles, processing, error, downloadUrl, progress } = active;

  const handleProcess = () => {
    if (files.length > 1) {
      processAllFiles(files, settings);
    } else {
      processFiles(files, settings);
    }
  };

  const hasFile = files.length > 0;
  const tab = settings.percentage !== undefined ? "scale" : "other";
  const canProcess =
    hasFile &&
    !processing &&
    (isContentAware
      ? Boolean(settings.width) || Boolean(settings.height) || Boolean(settings.square)
      : tab === "scale"
        ? Number(settings.percentage) > 0
        : Boolean(settings.width) || Boolean(settings.height));

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (canProcess) handleProcess();
  };

  return (
    <form onSubmit={handleSubmit} className="space-y-4">
      <ResizeControls onChange={handleSettingsChange} />

      {/* Error */}
      {error && <p className="text-xs text-destructive-ink">{error}</p>}

      {/* Process button */}
      {processing ? (
        <ProgressCard
          active={processing}
          phase={progress.phase === "idle" ? "uploading" : progress.phase}
          label={t.toolSettings.resize.progressLabel}
          stage={progress.stage}
          percent={progress.percent}
          elapsed={progress.elapsed}
        />
      ) : (
        <button
          type="submit"
          data-testid="resize-submit"
          disabled={!canProcess}
          className="w-full py-2.5 rounded-lg bg-primary text-primary-foreground font-medium disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
        >
          {files.length > 1
            ? format(t.toolSettings.resize.submitBatch, { count: files.length })
            : t.toolSettings.resize.submit}
        </button>
      )}

      {/* Download */}
      {downloadUrl && (
        <a
          href={downloadUrl}
          download
          data-testid="resize-download"
          className="w-full py-2.5 rounded-lg border border-primary text-primary-ink font-medium flex items-center justify-center gap-2 hover:bg-primary/5"
        >
          <Download className="h-4 w-4" />
          {t.common.download}
        </a>
      )}
    </form>
  );
}