import { useEffect, Fragment, useMemo, useState, useCallback, useRef } from "react";
import { useNavigate } from "react-router";
import {
  LuPenLine,
  LuCopy,
  LuMoveRight,
  LuCornerDownRight,
  LuArrowUp,
  LuArrowDown,
  LuTrash2,
  LuCommand,
  LuDownload,
} from "react-icons/lu";

import { KeySequence, useMacrosStore, generateMacroId } from "@/hooks/stores";
import { SettingsPageHeader } from "@/components/SettingsPageheader";
import { Button } from "@/components/Button";
import EmptyCard from "@/components/EmptyCard";
import Card from "@/components/Card";
import { MAX_TOTAL_MACROS, COPY_SUFFIX, DEFAULT_DELAY } from "@/constants/macros";
import notifications from "@/notifications";
import { ConfirmDialog } from "@/components/ConfirmDialog";
import LoadingSpinner from "@/components/LoadingSpinner";
import useKeyboardLayout from "@/hooks/useKeyboardLayout";

const normalizeSortOrders = (macros: KeySequence[]): KeySequence[] => macros.map((m, i) => ({ ...m, sortOrder: i + 1 }));

const pad2 = (n: number) => String(n).padStart(2, "0");

const buildMacroDownloadFilename = (macro: KeySequence) => {
  const safeName = (macro.name || macro.id).replace(/[^a-z0-9-_]+/gi, "-").toLowerCase();
  const now = new Date();
  const ts = `${now.getFullYear()}${pad2(now.getMonth() + 1)}${pad2(now.getDate())}-${pad2(now.getHours())}${pad2(now.getMinutes())}${pad2(now.getSeconds())}`;
  return `jetkvm-macro-${safeName}-${ts}.json`;
};

const sanitizeImportedStep = (raw: any) => ({
  keys: Array.isArray(raw?.keys) ? raw.keys.filter((k: any) => typeof k === "string") : [],
  modifiers: Array.isArray(raw?.modifiers) ? raw.modifiers.filter((m: any) => typeof m === "string") : [],
  delay: typeof raw?.delay === "number" ? raw.delay : DEFAULT_DELAY,
  text: typeof raw?.text === "string" ? raw.text : undefined,
  wait: typeof raw?.wait === "boolean" ? raw.wait : false,
});

const sanitizeImportedMacro = (raw: any, sortOrder: number): KeySequence => ({
  id: generateMacroId(),
  name: (typeof raw?.name === "string" && raw.name.trim() ? raw.name : "Imported Macro").slice(0, 50),
  steps: Array.isArray(raw?.steps) ? raw.steps.map(sanitizeImportedStep) : [],
  sortOrder,
});

export default function SettingsMacrosRoute() {
  const { macros, loading, initialized, loadMacros, saveMacros } = useMacrosStore();
  const navigate = useNavigate();
  const [actionLoadingId, setActionLoadingId] = useState<string | null>(null);
  const [showDeleteConfirm, setShowDeleteConfirm] = useState(false);
  const [macroToDelete, setMacroToDelete] = useState<KeySequence | null>(null);
  const { selectedKeyboard }  = useKeyboardLayout();
  const fileInputRef = useRef<HTMLInputElement>(null);

  const isMaxMacrosReached = useMemo(
    () => macros.length >= MAX_TOTAL_MACROS,
    [macros.length],
  );

  useEffect(() => {
    if (!initialized) {
      loadMacros();
    }
  }, [initialized, loadMacros]);

  const handleDuplicateMacro = useCallback(async (macro: KeySequence) => {
    if (!macro?.id || !macro?.name) {
      notifications.error("Invalid macro data");
      return;
    }
    if (isMaxMacrosReached) {
      notifications.error(`Maximum of ${MAX_TOTAL_MACROS} macros allowed`);
      return;
    }
    setActionLoadingId(macro.id);
    const newMacroCopy: KeySequence = {
      ...JSON.parse(JSON.stringify(macro)),
      id: generateMacroId(),
      name: `${macro.name} ${COPY_SUFFIX}`,
      sortOrder: macros.length + 1,
    };
    try {
      await saveMacros(normalizeSortOrders([...macros, newMacroCopy]));
      notifications.success(`Macro "${newMacroCopy.name}" duplicated successfully`);
    } catch (e: any) {
      notifications.error(`Failed to duplicate macro: ${e?.message || 'error'}`);
    } finally {
      setActionLoadingId(null);
    }
  }, [macros, saveMacros, isMaxMacrosReached]);

  const handleMoveMacro = useCallback(async (index: number, direction: "up" | "down", macroId: string) => {
    if (!Array.isArray(macros) || macros.length === 0) {
      notifications.error("No macros available");
      return;
    }
    const newIndex = direction === "up" ? index - 1 : index + 1;
    if (newIndex < 0 || newIndex >= macros.length) return;
    setActionLoadingId(macroId);
    try {
      const newMacros = [...macros];
      [newMacros[index], newMacros[newIndex]] = [newMacros[newIndex], newMacros[index]];
      const updatedMacros = normalizeSortOrders(newMacros);
      await saveMacros(updatedMacros);
      notifications.success("Macro order updated successfully");
    } catch (e: any) {
      notifications.error(`Failed to reorder macros: ${e?.message || 'error'}`);
    } finally {
      setActionLoadingId(null);
    }
  }, [macros, saveMacros]);

  const handleDeleteMacro = useCallback(async () => {
    if (!macroToDelete?.id) return;

    setActionLoadingId(macroToDelete.id);
    try {
      const updatedMacros = normalizeSortOrders(
        macros.filter(m => m.id !== macroToDelete.id),
      );
      await saveMacros(updatedMacros);
      notifications.success(`Macro "${macroToDelete.name}" deleted successfully`);
      setShowDeleteConfirm(false);
      setMacroToDelete(null);
    } catch (error: unknown) {
      if (error instanceof Error) {
        notifications.error(`Failed to delete macro: ${error.message}`);
      } else {
        notifications.error("Failed to delete macro");
      }
    } finally {
      setActionLoadingId(null);
    }
  }, [macroToDelete, macros, saveMacros]);

  const handleDownloadMacro = useCallback((macro: KeySequence) => {
    const data = JSON.stringify(macro, null, 2);
    const blob = new Blob([data], { type: "application/json" });
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = buildMacroDownloadFilename(macro);
    a.click();
    URL.revokeObjectURL(url);
  }, []);

  const MacroList = useMemo(
    () => (
      <div className="space-y-2">
        {macros.map((macro, index) => (
          <Card key={macro.id} className="bg-white p-2 dark:bg-slate-800">
            <div className="flex items-center justify-between">
              <div className="flex flex-col gap-1 px-2">
                <Button
                  size="XS"
                  theme="light"
                  onClick={() => handleMoveMacro(index, "up", macro.id)}
                  disabled={index === 0 || actionLoadingId === macro.id}
                  LeadingIcon={LuArrowUp}
                  aria-label={`Move ${macro.name} up`}
                />
                <Button
                  size="XS"
                  theme="light"
                  onClick={() => handleMoveMacro(index, "down", macro.id)}
                  disabled={index === macros.length - 1 || actionLoadingId === macro.id}
                  LeadingIcon={LuArrowDown}
                  aria-label={`Move ${macro.name} down`}
                />
              </div>

              <div className="ml-2 flex min-w-0 flex-1 flex-col justify-center">
                <h3 className="truncate text-sm font-semibold text-black dark:text-white">
                  {macro.name}
                </h3>
                <p className="mt-1 ml-4 overflow-hidden text-xs text-slate-500 dark:text-slate-400">
                  <span className="flex flex-col items-start gap-1">
                    {macro.steps.map((step, stepIndex) => {
                      const StepIcon = stepIndex === 0 ? LuMoveRight : LuCornerDownRight;

                      return (
                        <span key={stepIndex} className="inline-flex items-center">
                          <StepIcon className="mr-1 h-3 w-3 shrink-0 text-slate-400 dark:text-slate-500" />
                          <span className="rounded-md border border-slate-200/50 bg-slate-50 px-2 py-0.5 dark:border-slate-700/50 dark:bg-slate-800">
                            {step.text && step.text.length > 0 ? (
                              <span className="font-medium text-emerald-700 dark:text-emerald-300">Text: "{step.text}"</span>
                            ) : step.wait ? (
                              <span className="font-medium text-amber-600 dark:text-amber-300">Wait</span>
                            ) : (Array.isArray(step.modifiers) && step.modifiers.length > 0) ||
                              (Array.isArray(step.keys) && step.keys.length > 0) ? (
                              <>
                                {Array.isArray(step.modifiers) &&
                                  step.modifiers.map((modifier, idx) => (
                                    <Fragment key={`mod-${idx}`}>
                                      <span className="font-medium text-slate-600 dark:text-slate-200">
                                        {selectedKeyboard.modifierDisplayMap[modifier] || modifier}
                                      </span>
                                      {idx < step.modifiers.length - 1 && (
                                        <span className="text-slate-400 dark:text-slate-600">
                                          {" "}
                                          +{" "}
                                        </span>
                                      )}
                                    </Fragment>
                                  ))}

                                {Array.isArray(step.modifiers) &&
                                  step.modifiers.length > 0 &&
                                  Array.isArray(step.keys) &&
                                  step.keys.length > 0 && (
                                    <span className="text-slate-400 dark:text-slate-600">
                                      {" "}
                                      +{" "}
                                    </span>
                                  )}

                                {Array.isArray(step.keys) &&
                                  step.keys.map((key, idx) => (
                                    <Fragment key={`key-${idx}`}>
                                      <span className="font-medium text-blue-600 dark:text-blue-400">
                                        {selectedKeyboard.keyDisplayMap[key] || key}
                                      </span>
                                      {idx < step.keys.length - 1 && (
                                        <span className="text-slate-400 dark:text-slate-600">
                                          {" "}
                                          +{" "}
                                        </span>
                                      )}
                                    </Fragment>
                                  ))}
                              </>
                            ) : (
                              <span className="font-medium text-slate-500 dark:text-slate-400">
                                Pause only
                              </span>
                            )}
                            {step.delay !== DEFAULT_DELAY && (
                              <span className="ml-1 text-slate-400 dark:text-slate-500">
                                ({step.delay}ms)
                              </span>
                            )}
                          </span>
                        </span>
                      );
                    })}
                  </span>
                </p>
              </div>

              <div className="ml-4 flex items-center gap-1">
                <Button
                  size="XS"
                  className="text-red-500 dark:text-red-400"
                  theme="light"
                  LeadingIcon={LuTrash2}
                  onClick={() => {
                    setMacroToDelete(macro);
                    setShowDeleteConfirm(true);
                  }}
                  disabled={actionLoadingId === macro.id}
                  aria-label={`Delete macro ${macro.name}`}
                />
                <Button
                  size="XS"
                  theme="light"
                  LeadingIcon={LuCopy}
                  onClick={() => handleDuplicateMacro(macro)}
                  disabled={actionLoadingId === macro.id}
                  aria-label={`Duplicate macro ${macro.name}`}
                />
                <Button size="XS" theme="light" LeadingIcon={LuDownload} onClick={() => handleDownloadMacro(macro)} aria-label={`Download macro ${macro.name}`} disabled={actionLoadingId === macro.id} />
                <Button
                  size="XS"
                  theme="light"
                  LeadingIcon={LuPenLine}
                  text="Edit"
                  onClick={() => navigate(`${macro.id}/edit`)}
                  disabled={actionLoadingId === macro.id}
                  aria-label={`Edit macro ${macro.name}`}
                />
              </div>
            </div>
          </Card>
        ))}

        <ConfirmDialog
          open={showDeleteConfirm}
          onClose={() => {
            setShowDeleteConfirm(false);
            setMacroToDelete(null);
          }}
          title="Delete Macro"
          description={`Are you sure you want to delete "${macroToDelete?.name}"? This action cannot be undone.`}
          variant="danger"
          confirmText={actionLoadingId === macroToDelete?.id ? "Deleting..." : "Delete"}
          onConfirm={handleDeleteMacro}
          isConfirming={actionLoadingId === macroToDelete?.id}
        />
      </div>
    ),
    [macros, showDeleteConfirm, macroToDelete?.name, macroToDelete?.id, actionLoadingId, handleDeleteMacro, handleMoveMacro, selectedKeyboard.modifierDisplayMap, selectedKeyboard.keyDisplayMap, handleDuplicateMacro, navigate, handleDownloadMacro],
  );

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <SettingsPageHeader
          title="Keyboard Macros"
          description={`Combine keystrokes into a single action for faster workflows.`}
        />
        <div className="flex items-center pl-2">
          <Button
            size="SM"
            theme="primary"
            text={isMaxMacrosReached ? `Max Reached` : "Add New Macro"}
            onClick={() => navigate("add")}
            disabled={isMaxMacrosReached}
            aria-label="Add new macro"
          />
          <div className="ml-2 flex items-center gap-2">
            <input ref={fileInputRef} type="file" accept="application/json" multiple className="hidden" onChange={async e => {
              const fl = e.target.files;
              if (!fl || fl.length === 0) return;
              let working = [...macros];
              const imported: string[] = [];
              let errors = 0;
              let skipped = 0;
              for (const f of Array.from(fl)) {
                if (working.length >= MAX_TOTAL_MACROS) { skipped++; continue; }
                try {
                  const raw = await f.text();
                  const parsed = JSON.parse(raw);
                  const candidates = Array.isArray(parsed) ? parsed : [parsed];
                  for (const c of candidates) {
                    if (working.length >= MAX_TOTAL_MACROS) { skipped += (candidates.length - candidates.indexOf(c)); break; }
                    if (!c || typeof c !== "object") { errors++; continue; }
                    const sanitized = sanitizeImportedMacro(c, working.length + 1);
                    working.push(sanitized);
                    imported.push(sanitized.name);
                  }
                } catch { errors++; }
              }
              try {
                if (imported.length) {
                  await saveMacros(normalizeSortOrders(working));
                  notifications.success(`Imported ${imported.length} macro${imported.length === 1 ? '' : 's'}`);
                }
                if (errors) notifications.error(`${errors} file${errors === 1 ? '' : 's'} failed`);
                if (skipped) notifications.error(`${skipped} macro${skipped === 1 ? '' : 's'} skipped (limit ${MAX_TOTAL_MACROS})`);
              } finally {
                if (fileInputRef.current) fileInputRef.current.value = '';
              }
            }} />
            <Button
              size="SM"
              theme="light"
              text="Import Macro"
              onClick={() => fileInputRef.current?.click()}
            />
          </div>
        </div>
      </div>

      <div className="space-y-4">
        {loading && macros.length === 0 ? (
          <EmptyCard
            IconElm={LuCommand}
            headline="Loading macros..."
            BtnElm={
              <div className="my-2 flex flex-col items-center space-y-2 text-center">
                <LoadingSpinner className="h-6 w-6 text-blue-700 dark:text-blue-500" />
              </div>
            }
          />
        ) : macros.length === 0 ? (
          <EmptyCard
            IconElm={LuCommand}
            headline="Create Your First Macro"
            description="Combine keystrokes into a single action"
            BtnElm={
              <Button
                size="SM"
                theme="primary"
                text="Add New Macro"
                onClick={() => navigate("add")}
                disabled={isMaxMacrosReached}
                aria-label="Add new macro"
              />
            }
          />
        ) : (
          MacroList
        )}
      </div>
    </div>
  );
}