"use client";

import { useState, useEffect, useRef } from "react";
import { Card, Button, Toggle, Input } from "@/shared/components";
import { useTheme } from "@/shared/hooks/useTheme";
import { cn } from "@/shared/utils/cn";
import { APP_CONFIG } from "@/shared/constants/config";

export default function ProfilePage() {
  const { theme, setTheme, isDark } = useTheme();
  const [settings, setSettings] = useState({ fallbackStrategy: "fill-first" });
  const [loading, setLoading] = useState(true);
  const [passwords, setPasswords] = useState({ current: "", new: "", confirm: "" });
  const [passStatus, setPassStatus] = useState({ type: "", message: "" });
  const [passLoading, setPassLoading] = useState(false);
  const [dbLoading, setDbLoading] = useState(false);
  const [dbStatus, setDbStatus] = useState({ type: "", message: "" });
  const importFileRef = useRef(null);
  const [proxyForm, setProxyForm] = useState({
    outboundProxyEnabled: false,
    outboundProxyUrl: "",
    outboundNoProxy: "",
  });
  const [proxyStatus, setProxyStatus] = useState({ type: "", message: "" });
  const [proxyLoading, setProxyLoading] = useState(false);
  const [proxyTestLoading, setProxyTestLoading] = useState(false);

  useEffect(() => {
    fetch("/api/settings")
      .then((res) => res.json())
      .then((data) => {
        setSettings(data);
        setProxyForm({
          outboundProxyEnabled: data?.outboundProxyEnabled === true,
          outboundProxyUrl: data?.outboundProxyUrl || "",
          outboundNoProxy: data?.outboundNoProxy || "",
        });
        setLoading(false);
      })
      .catch((err) => {
        console.error("Failed to fetch settings:", err);
        setLoading(false);
      });
  }, []);

  const updateOutboundProxy = async (e) => {
    e.preventDefault();
    if (settings.outboundProxyEnabled !== true) return;
    setProxyLoading(true);
    setProxyStatus({ type: "", message: "" });

    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          outboundProxyUrl: proxyForm.outboundProxyUrl,
          outboundNoProxy: proxyForm.outboundNoProxy,
        }),
      });

      const data = await res.json();
      if (res.ok) {
        setSettings((prev) => ({ ...prev, ...data }));
        setProxyStatus({ type: "success", message: "Proxy settings applied" });
      } else {
        setProxyStatus({ type: "error", message: data.error || "Failed to update proxy settings" });
      }
    } catch (err) {
      setProxyStatus({ type: "error", message: "An error occurred" });
    } finally {
      setProxyLoading(false);
    }
  };

  const testOutboundProxy = async () => {
    if (settings.outboundProxyEnabled !== true) return;

    const proxyUrl = (proxyForm.outboundProxyUrl || "").trim();
    if (!proxyUrl) {
      setProxyStatus({ type: "error", message: "Please enter a Proxy URL to test" });
      return;
    }

    setProxyTestLoading(true);
    setProxyStatus({ type: "", message: "" });

    try {
      const res = await fetch("/api/settings/proxy-test", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ proxyUrl }),
      });

      const data = await res.json();
      if (res.ok && data?.ok) {
        setProxyStatus({
          type: "success",
          message: `Proxy test OK (${data.status}) in ${data.elapsedMs}ms`,
        });
      } else {
        setProxyStatus({
          type: "error",
          message: data?.error || "Proxy test failed",
        });
      }
    } catch (err) {
      setProxyStatus({ type: "error", message: "An error occurred" });
    } finally {
      setProxyTestLoading(false);
    }
  };

  const updateOutboundProxyEnabled = async (outboundProxyEnabled) => {
    setProxyLoading(true);
    setProxyStatus({ type: "", message: "" });

    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ outboundProxyEnabled }),
      });

      const data = await res.json();
      if (res.ok) {
        setSettings((prev) => ({ ...prev, ...data }));
        setProxyForm((prev) => ({ ...prev, outboundProxyEnabled: data?.outboundProxyEnabled === true }));
        setProxyStatus({
          type: "success",
          message: outboundProxyEnabled ? "Proxy enabled" : "Proxy disabled",
        });
      } else {
        setProxyStatus({ type: "error", message: data.error || "Failed to update proxy settings" });
      }
    } catch (err) {
      setProxyStatus({ type: "error", message: "An error occurred" });
    } finally {
      setProxyLoading(false);
    }
  };

  const handlePasswordChange = async (e) => {
    e.preventDefault();
    if (passwords.new !== passwords.confirm) {
      setPassStatus({ type: "error", message: "Passwords do not match" });
      return;
    }

    setPassLoading(true);
    setPassStatus({ type: "", message: "" });

    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          currentPassword: passwords.current,
          newPassword: passwords.new,
        }),
      });

      const data = await res.json();

      if (res.ok) {
        setPassStatus({ type: "success", message: "Password updated successfully" });
        setPasswords({ current: "", new: "", confirm: "" });
      } else {
        setPassStatus({ type: "error", message: data.error || "Failed to update password" });
      }
    } catch (err) {
      setPassStatus({ type: "error", message: "An error occurred" });
    } finally {
      setPassLoading(false);
    }
  };

  const updateFallbackStrategy = async (strategy) => {
    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ fallbackStrategy: strategy }),
      });
      if (res.ok) {
        setSettings(prev => ({ ...prev, fallbackStrategy: strategy }));
      }
    } catch (err) {
      console.error("Failed to update settings:", err);
    }
  };

  const updateStickyLimit = async (limit) => {
    const numLimit = parseInt(limit);
    if (isNaN(numLimit) || numLimit < 1) return;

    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ stickyRoundRobinLimit: numLimit }),
      });
      if (res.ok) {
        setSettings(prev => ({ ...prev, stickyRoundRobinLimit: numLimit }));
      }
    } catch (err) {
      console.error("Failed to update sticky limit:", err);
    }
  };

  const updateRequireLogin = async (requireLogin) => {
    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ requireLogin }),
      });
      if (res.ok) {
        setSettings(prev => ({ ...prev, requireLogin }));
      }
    } catch (err) {
      console.error("Failed to update require login:", err);
    }
  };

  const updateObservabilitySetting = async (key, value) => {
    const numValue = parseInt(value);
    if (isNaN(numValue) || numValue < 1) return;

    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ [key]: numValue }),
      });
      if (res.ok) {
        setSettings(prev => ({ ...prev, [key]: numValue }));
      }
    } catch (err) {
      console.error(`Failed to update ${key}:`, err);
    }
  };

  const updateObservabilityEnabled = async (enabled) => {
    try {
      const res = await fetch("/api/settings", {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ observabilityEnabled: enabled }),
      });
      if (res.ok) {
        setSettings(prev => ({ ...prev, observabilityEnabled: enabled }));
      }
    } catch (err) {
      console.error("Failed to update observabilityEnabled:", err);
    }
  };

  const reloadSettings = async () => {
    try {
      const res = await fetch("/api/settings");
      if (!res.ok) return;
      const data = await res.json();
      setSettings(data);
    } catch (err) {
      console.error("Failed to reload settings:", err);
    }
  };

  const handleExportDatabase = async () => {
    setDbLoading(true);
    setDbStatus({ type: "", message: "" });
    try {
      const res = await fetch("/api/settings/database");
      if (!res.ok) {
        const data = await res.json().catch(() => ({}));
        throw new Error(data.error || "Failed to export database");
      }

      const payload = await res.json();
      const content = JSON.stringify(payload, null, 2);
      const blob = new Blob([content], { type: "application/json" });
      const url = URL.createObjectURL(blob);
      const anchor = document.createElement("a");
      const stamp = new Date().toISOString().replace(/[.:]/g, "-");
      anchor.href = url;
      anchor.download = `9router-backup-${stamp}.json`;
      document.body.appendChild(anchor);
      anchor.click();
      document.body.removeChild(anchor);
      URL.revokeObjectURL(url);

      setDbStatus({ type: "success", message: "Database backup downloaded" });
    } catch (err) {
      setDbStatus({ type: "error", message: err.message || "Failed to export database" });
    } finally {
      setDbLoading(false);
    }
  };

  const handleImportDatabase = async (event) => {
    const file = event.target.files?.[0];
    if (!file) return;

    setDbLoading(true);
    setDbStatus({ type: "", message: "" });

    try {
      const raw = await file.text();
      const payload = JSON.parse(raw);

      const res = await fetch("/api/settings/database", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
      });

      const data = await res.json().catch(() => ({}));
      if (!res.ok) {
        throw new Error(data.error || "Failed to import database");
      }

      await reloadSettings();
      setDbStatus({ type: "success", message: "Database imported successfully" });
    } catch (err) {
      setDbStatus({ type: "error", message: err.message || "Invalid backup file" });
    } finally {
      if (importFileRef.current) {
        importFileRef.current.value = "";
      }
      setDbLoading(false);
    }
  };

  const observabilityEnabled = settings.observabilityEnabled !== false;

  return (
    <div className="max-w-2xl mx-auto">
      <div className="flex flex-col gap-6">
        {/* Local Mode Info */}
        <Card>
          <div className="flex items-center gap-4 mb-4">
            <div className="size-12 rounded-lg bg-green-500/10 text-green-500 flex items-center justify-center">
              <span className="material-symbols-outlined text-2xl">computer</span>
            </div>
            <div>
              <h2 className="text-xl font-semibold">Local Mode</h2>
              <p className="text-text-muted">Running on your machine</p>
            </div>
          </div>
          <div className="pt-4 border-t border-border">
            <p className="text-sm text-text-muted">
              All data is stored locally in the <code className="bg-sidebar px-1 rounded">~/.9router/db.json</code> file.
            </p>
          </div>
        </Card>

        {/* Security */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-primary/10 text-primary">
              <span className="material-symbols-outlined text-[20px]">shield</span>
            </div>
            <h3 className="text-lg font-semibold">Security</h3>
          </div>
          <div className="flex flex-col gap-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Require login</p>
                <p className="text-sm text-text-muted">
                  When ON, dashboard requires password. When OFF, access without login.
                </p>
              </div>
              <Toggle
                checked={settings.requireLogin === true}
                onChange={() => updateRequireLogin(!settings.requireLogin)}
                disabled={loading}
              />
            </div>
            {settings.requireLogin === true && (
              <form onSubmit={handlePasswordChange} className="flex flex-col gap-4 pt-4 border-t border-border/50">
                {settings.hasPassword && (
                  <div className="flex flex-col gap-2">
                    <label className="text-sm font-medium">Current Password</label>
                    <Input
                      type="password"
                      placeholder="Enter current password"
                      value={passwords.current}
                      onChange={(e) => setPasswords({ ...passwords, current: e.target.value })}
                      required
                    />
                  </div>
                )}
                {/* {!settings.hasPassword && (
                  <div className="p-3 rounded-lg bg-blue-500/10 border border-blue-500/20">
                    <p className="text-sm text-blue-600 dark:text-blue-400">
                      Setting password for the first time. Leave current password empty or use default: <code className="bg-blue-500/20 px-1 rounded">123456</code>
                    </p>
                  </div>
                )} */}
                <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
                  <div className="flex flex-col gap-2">
                    <label className="text-sm font-medium">New Password</label>
                    <Input
                      type="password"
                      placeholder="Enter new password"
                      value={passwords.new}
                      onChange={(e) => setPasswords({ ...passwords, new: e.target.value })}
                      required
                    />
                  </div>
                  <div className="flex flex-col gap-2">
                    <label className="text-sm font-medium">Confirm New Password</label>
                    <Input
                      type="password"
                      placeholder="Confirm new password"
                      value={passwords.confirm}
                      onChange={(e) => setPasswords({ ...passwords, confirm: e.target.value })}
                      required
                    />
                  </div>
                </div>

                {passStatus.message && (
                  <p className={`text-sm ${passStatus.type === "error" ? "text-red-500" : "text-green-500"}`}>
                    {passStatus.message}
                  </p>
                )}

                <div className="pt-2">
                  <Button type="submit" variant="primary" loading={passLoading}>
                    {settings.hasPassword ? "Update Password" : "Set Password"}
                  </Button>
                </div>
              </form>
            )}
          </div>
        </Card>

        {/* Routing Preferences */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-blue-500/10 text-blue-500">
              <span className="material-symbols-outlined text-[20px]">route</span>
            </div>
            <h3 className="text-lg font-semibold">Routing Strategy</h3>
          </div>
          <div className="flex flex-col gap-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Round Robin</p>
                <p className="text-sm text-text-muted">
                  Cycle through accounts to distribute load
                </p>
              </div>
              <Toggle
                checked={settings.fallbackStrategy === "round-robin"}
                onChange={() => updateFallbackStrategy(settings.fallbackStrategy === "round-robin" ? "fill-first" : "round-robin")}
                disabled={loading}
              />
            </div>

            {/* Sticky Round Robin Limit */}
            {settings.fallbackStrategy === "round-robin" && (
              <div className="flex items-center justify-between pt-2 border-t border-border/50">
                <div>
                  <p className="font-medium">Sticky Limit</p>
                  <p className="text-sm text-text-muted">
                    Calls per account before switching
                  </p>
                </div>
                <Input
                  type="number"
                  min="1"
                  max="10"
                  value={settings.stickyRoundRobinLimit || 3}
                  onChange={(e) => updateStickyLimit(e.target.value)}
                  disabled={loading}
                  className="w-20 text-center"
                />
              </div>
            )}

            <p className="text-xs text-text-muted italic pt-2 border-t border-border/50">
              {settings.fallbackStrategy === "round-robin"
                ? `Currently distributing requests across all available accounts with ${settings.stickyRoundRobinLimit || 3} calls per account.`
                : "Currently using accounts in priority order (Fill First)."}
            </p>
          </div>
        </Card>

        {/* Network */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-purple-500/10 text-purple-500">
              <span className="material-symbols-outlined text-[20px]">wifi</span>
            </div>
            <h3 className="text-lg font-semibold">Network</h3>
          </div>

          <div className="flex flex-col gap-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Outbound Proxy</p>
                <p className="text-sm text-text-muted">Enable proxy for OAuth + provider outbound requests.</p>
              </div>
              <Toggle
                checked={settings.outboundProxyEnabled === true}
                onChange={() => updateOutboundProxyEnabled(!(settings.outboundProxyEnabled === true))}
                disabled={loading || proxyLoading}
              />
            </div>

            {settings.outboundProxyEnabled === true && (
              <form onSubmit={updateOutboundProxy} className="flex flex-col gap-4 pt-2 border-t border-border/50">
                <div className="flex flex-col gap-2">
                  <label className="font-medium">Proxy URL</label>
                  <Input
                    placeholder="http://127.0.0.1:7897"
                    value={proxyForm.outboundProxyUrl}
                    onChange={(e) => setProxyForm((prev) => ({ ...prev, outboundProxyUrl: e.target.value }))}
                    disabled={loading || proxyLoading}
                  />
                  <p className="text-sm text-text-muted">Leave empty to inherit existing env proxy (if any).</p>
                </div>

                <div className="flex flex-col gap-2 pt-2 border-t border-border/50">
                  <label className="font-medium">No Proxy</label>
                  <Input
                    placeholder="localhost,127.0.0.1"
                    value={proxyForm.outboundNoProxy}
                    onChange={(e) => setProxyForm((prev) => ({ ...prev, outboundNoProxy: e.target.value }))}
                    disabled={loading || proxyLoading}
                  />
                  <p className="text-sm text-text-muted">Comma-separated hostnames/domains to bypass the proxy.</p>
                </div>

                <div className="pt-2 border-t border-border/50 flex items-center gap-2">
                  <Button
                    type="button"
                    variant="secondary"
                    loading={proxyTestLoading}
                    disabled={loading || proxyLoading}
                    onClick={testOutboundProxy}
                  >
                    Test proxy URL
                  </Button>
                  <Button type="submit" variant="primary" loading={proxyLoading}>
                    Apply
                  </Button>
                </div>
              </form>
            )}

            {proxyStatus.message && (
              <p className={`text-sm ${proxyStatus.type === "error" ? "text-red-500" : "text-green-500"} pt-2 border-t border-border/50`}>
                {proxyStatus.message}
              </p>
            )}
          </div>
        </Card>

        {/* Theme Preferences */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-purple-500/10 text-purple-500">
              <span className="material-symbols-outlined text-[20px]">palette</span>
            </div>
            <h3 className="text-lg font-semibold">Appearance</h3>
          </div>
          <div className="flex flex-col gap-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Dark Mode</p>
                <p className="text-sm text-text-muted">
                  Switch between light and dark themes
                </p>
              </div>
              <Toggle
                checked={isDark}
                onChange={() => setTheme(isDark ? "light" : "dark")}
              />
            </div>

            {/* Theme Options */}
            <div className="pt-4 border-t border-border">
              <div className="inline-flex p-1 rounded-lg bg-black/5 dark:bg-white/5">
                {["light", "dark", "system"].map((option) => (
                  <button
                    key={option}
                    type="button"
                    onClick={() => setTheme(option)}
                    className={cn(
                      "flex items-center gap-2 px-4 py-2 rounded-md font-medium transition-all",
                      theme === option
                        ? "bg-white dark:bg-white/10 text-text-main shadow-sm"
                        : "text-text-muted hover:text-text-main"
                    )}
                  >
                    <span className="material-symbols-outlined text-[20px]">
                      {option === "light" ? "light_mode" : option === "dark" ? "dark_mode" : "contrast"}
                    </span>
                    <span className="capitalize">{option}</span>
                  </button>
                ))}
              </div>
            </div>
          </div>
        </Card>

        {/* Data Management */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-green-500/10 text-green-500">
              <span className="material-symbols-outlined text-[20px]">database</span>
            </div>
            <h3 className="text-lg font-semibold">Data</h3>
          </div>
          <div className="flex flex-col gap-3">
            <div className="flex items-center justify-between p-4 rounded-lg bg-bg border border-border">
              <div>
                <p className="font-medium">Database Location</p>
                <p className="text-sm text-text-muted font-mono">~/.9router/db.json</p>
              </div>
            </div>
            <div className="flex flex-wrap gap-2">
              <Button
                variant="secondary"
                icon="download"
                onClick={handleExportDatabase}
                loading={dbLoading}
              >
                Download Backup
              </Button>
              <Button
                variant="outline"
                icon="upload"
                onClick={() => importFileRef.current?.click()}
                disabled={dbLoading}
              >
                Import Backup
              </Button>
              <input
                ref={importFileRef}
                type="file"
                accept="application/json,.json"
                className="hidden"
                onChange={handleImportDatabase}
              />
            </div>
            {dbStatus.message && (
              <p className={`text-sm ${dbStatus.type === "error" ? "text-red-500" : "text-green-600 dark:text-green-400"}`}>
                {dbStatus.message}
              </p>
            )}
          </div>
        </Card>

        {/* Observability Settings */}
        <Card>
          <div className="flex items-center gap-3 mb-4">
            <div className="p-2 rounded-lg bg-orange-500/10 text-orange-500">
              <span className="material-symbols-outlined text-[20px]">monitoring</span>
            </div>
            <h3 className="text-lg font-semibold">Observability</h3>
          </div>
          <div className="flex flex-col gap-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Enable Observability</p>
                <p className="text-sm text-text-muted">
                  Turn request detail recording on/off globally
                </p>
              </div>
              <Toggle
                checked={observabilityEnabled}
                onChange={updateObservabilityEnabled}
                disabled={loading}
              />
            </div>

            <div className={cn("flex flex-col gap-4", !observabilityEnabled && "opacity-60")}>
            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Max Records</p>
                <p className="text-sm text-text-muted">
                  Maximum request detail records to keep (older records are auto-deleted)
                </p>
              </div>
              <Input
                type="number"
                min="100"
                max="10000"
                step="100"
                value={settings.observabilityMaxRecords || 1000}
                onChange={(e) => updateObservabilitySetting("observabilityMaxRecords", parseInt(e.target.value))}
                disabled={loading || !observabilityEnabled}
                className="w-28 text-center"
              />
            </div>

            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Batch Size</p>
                <p className="text-sm text-text-muted">
                  Number of items to accumulate before writing to database (higher = better performance)
                </p>
              </div>
              <Input
                type="number"
                min="5"
                max="100"
                step="5"
                value={settings.observabilityBatchSize || 20}
                onChange={(e) => updateObservabilitySetting("observabilityBatchSize", parseInt(e.target.value))}
                disabled={loading || !observabilityEnabled}
                className="w-28 text-center"
              />
            </div>

            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Flush Interval (ms)</p>
                <p className="text-sm text-text-muted">
                  Maximum time to wait before flushing buffer (prevents data loss during low traffic)
                </p>
              </div>
              <Input
                type="number"
                min="1000"
                max="30000"
                step="1000"
                value={settings.observabilityFlushIntervalMs || 5000}
                onChange={(e) => updateObservabilitySetting("observabilityFlushIntervalMs", parseInt(e.target.value))}
                disabled={loading || !observabilityEnabled}
                className="w-28 text-center"
              />
            </div>

            <div className="flex items-center justify-between">
              <div>
                <p className="font-medium">Max JSON Size (KB)</p>
                <p className="text-sm text-text-muted">
                  Maximum size for each JSON field (request/response) before truncation
                </p>
              </div>
              <Input
                type="number"
                min="100"
                max="10240"
                step="100"
                value={settings.observabilityMaxJsonSize || 1024}
                onChange={(e) => updateObservabilitySetting("observabilityMaxJsonSize", parseInt(e.target.value))}
                disabled={loading || !observabilityEnabled}
                className="w-28 text-center"
              />
            </div>

            <p className="text-xs text-text-muted italic pt-2 border-t border-border/50">
              Current: Keeps {settings.observabilityMaxRecords || 1000} records, batches every {settings.observabilityBatchSize || 20} requests, max {settings.observabilityMaxJsonSize || 1024}KB per field
            </p>
            </div>
          </div>
        </Card>

        {/* App Info */}
        <div className="text-center text-sm text-text-muted py-4">
          <p>{APP_CONFIG.name} v{APP_CONFIG.version}</p>
          <p className="mt-1">Local Mode - All data stored on your machine</p>
        </div>
      </div>
    </div>
  );
}