import { useState, useEffect, useCallback } from "react";
import { Outlet, Link, useLocation, useNavigate } from "react-router-dom";
import { Terminal } from "../components/terminal/Terminal";
import { useWebSocket } from "../hooks/useWebSocket";
import { useTheme } from "../hooks/useTheme";
import {
  Code2,
  Wrench,
  Hammer,
  Play,
  GitBranch,
  Settings,
  Sun,
  Moon,
  Terminal as TerminalIcon,
  ChevronDown,
  ChevronUp,
} from "lucide-react";
import type { LucideIcon } from "lucide-react";

const NAV_ITEMS: { path: string; label: string; Icon: LucideIcon }[] = [
  { path: "/editor", label: "Editor", Icon: Code2 },
  { path: "/toolset", label: "Toolset", Icon: Wrench },
  { path: "/build", label: "Build", Icon: Hammer },
  { path: "/server", label: "Server", Icon: Play },
  { path: "/repos", label: "Repos", Icon: GitBranch },
  { path: "/settings", label: "Settings", Icon: Settings },
];

export function IDELayout({ sidebar }: { sidebar?: React.ReactNode }) {
  const [terminalOpen, setTerminalOpen] = useState(false);
  const [upstreamBehind, setUpstreamBehind] = useState(0);
  const [pendingToolset, setPendingToolset] = useState(0);
  const location = useLocation();
  const navigate = useNavigate();
  const { subscribe } = useWebSocket();
  const { theme, toggleTheme } = useTheme();
  const showSidebar = location.pathname === "/editor" || location.pathname.startsWith("/editor/");

  useEffect(() => {
    return subscribe("git:upstream-update", (event) => {
      const data = event.data as { behind: number };
      if (data.behind > 0) {
        setUpstreamBehind((prev) => prev + data.behind);
      }
    });
  }, [subscribe]);

  useEffect(() => {
    return subscribe("toolset:changes", (event) => {
      const data = event.data as { count?: number };
      if (data.count !== undefined) setPendingToolset(data.count);
    });
  }, [subscribe]);

  useEffect(() => {
    if (location.pathname === "/repos") setUpstreamBehind(0);
  }, [location.pathname]);

  useEffect(() => {
    if (location.pathname === "/toolset") setPendingToolset(0);
  }, [location.pathname]);

  const handleKeyDown = useCallback(
    (e: KeyboardEvent) => {
      const tag = (e.target as HTMLElement)?.tagName;
      if (tag === "INPUT" || tag === "TEXTAREA" || (e.target as HTMLElement)?.closest?.(".monaco-editor")) {
        return;
      }

      if (e.ctrlKey && e.shiftKey && e.key === "B") {
        e.preventDefault();
        navigate("/build");
      } else if (e.ctrlKey && e.key === "`") {
        e.preventDefault();
        setTerminalOpen((v) => !v);
      } else if (e.ctrlKey && e.shiftKey && e.key === "F") {
        e.preventDefault();
        navigate("/editor");
      } else if (e.ctrlKey && e.shiftKey && e.key === "G") {
        e.preventDefault();
        navigate("/repos");
      } else if (e.ctrlKey && e.key === ",") {
        e.preventDefault();
        navigate("/settings");
      }
    },
    [navigate],
  );

  useEffect(() => {
    window.addEventListener("keydown", handleKeyDown);
    return () => window.removeEventListener("keydown", handleKeyDown);
  }, [handleKeyDown]);

  const getBadge = (path: string): number => {
    if (path === "/repos") return upstreamBehind;
    if (path === "/toolset") return pendingToolset;
    return 0;
  };

  return (
    <div style={{ display: "flex", height: "100vh", overflow: "hidden", backgroundColor: "var(--forge-bg)" }}>
      {/* Left sidebar nav */}
      <nav
        aria-label="Main navigation"
        style={{
          display: "flex",
          flexDirection: "column",
          width: "56px",
          flexShrink: 0,
          borderRight: "1px solid var(--forge-border)",
          backgroundColor: "var(--forge-surface)",
        }}
      >
        <Link
          to="/"
          style={{ display: "flex", alignItems: "center", justifyContent: "center", padding: "0.75rem 0", textDecoration: "none" }}
          title="Dashboard"
        >
          <img src="/layonara.png" alt="Layonara" style={{ width: "36px" }} />
        </Link>

        <div style={{ marginTop: "0.25rem", display: "flex", flexDirection: "column", flex: 1 }}>
          {NAV_ITEMS.map((item) => {
            const isActive =
              item.path === "/"
                ? location.pathname === "/"
                : location.pathname.startsWith(item.path);
            const badge = getBadge(item.path);

            return (
              <Link
                key={item.path}
                to={item.path}
                style={{
                  display: "flex",
                  flexDirection: "column",
                  alignItems: "center",
                  justifyContent: "center",
                  padding: "0.625rem 0",
                  position: "relative",
                  textDecoration: "none",
                  transition: "background-color 150ms, color 150ms",
                  backgroundColor: isActive ? "var(--forge-accent-subtle)" : undefined,
                  color: isActive ? "var(--forge-accent)" : "var(--forge-text-secondary)",
                }}
                onMouseEnter={(e) => { if (!isActive) e.currentTarget.style.backgroundColor = "var(--forge-surface-raised)"; }}
                onMouseLeave={(e) => { if (!isActive) e.currentTarget.style.backgroundColor = isActive ? "var(--forge-accent-subtle)" : ""; }}
                title={item.label}
              >
                <item.Icon size={18} strokeWidth={isActive ? 2.5 : 2} />
                <span style={{ marginTop: "0.25rem", fontSize: "0.625rem", fontWeight: 500, lineHeight: 1 }}>{item.label}</span>
                {badge > 0 && (
                  <span
                    style={{
                      position: "absolute",
                      right: "0.25rem",
                      top: "0.25rem",
                      display: "flex",
                      height: "0.875rem",
                      minWidth: "0.875rem",
                      alignItems: "center",
                      justifyContent: "center",
                      borderRadius: "9999px",
                      padding: "0 0.125rem",
                      fontSize: "8px",
                      fontWeight: 700,
                      lineHeight: 1,
                      backgroundColor: "var(--forge-accent)",
                      color: "var(--forge-accent-text)",
                    }}
                  >
                    {badge}
                  </span>
                )}
              </Link>
            );
          })}
        </div>

        <button
          onClick={toggleTheme}
          style={{
            display: "flex",
            flexDirection: "column",
            alignItems: "center",
            justifyContent: "center",
            padding: "0.625rem 0",
            color: "var(--forge-text-secondary)",
            background: "none",
            border: "none",
            width: "100%",
            transition: "background-color 150ms, color 150ms",
          }}
          title={`Switch to ${theme === "dark" ? "light" : "dark"} mode`}
          onMouseEnter={(e) => { e.currentTarget.style.backgroundColor = "var(--forge-surface-raised)"; }}
          onMouseLeave={(e) => { e.currentTarget.style.backgroundColor = ""; }}
        >
          {theme === "dark" ? <Sun size={18} /> : <Moon size={18} />}
          <span style={{ marginTop: "0.25rem", fontSize: "0.625rem", fontWeight: 500, lineHeight: 1 }}>{theme === "dark" ? "Light" : "Dark"}</span>
        </button>
      </nav>

      {/* Main content area */}
      <div style={{ display: "flex", flexDirection: "column", flex: 1, overflow: "hidden" }}>
        <header
          style={{
            display: "flex",
            alignItems: "center",
            gap: "1rem",
            padding: "0.375rem 1rem",
            borderBottom: "1px solid var(--forge-border)",
            flexShrink: 0,
          }}
        >
          <span
            style={{
              fontFamily: "var(--font-heading)",
              fontSize: "var(--text-lg)",
              fontWeight: 700,
              color: "var(--forge-accent)",
            }}
          >
            Layonara Forge
          </span>
        </header>

        <div style={{ display: "flex", flex: 1, overflow: "hidden" }}>
          {sidebar && showSidebar && (
            <aside
              style={{
                width: "250px",
                flexShrink: 0,
                overflow: "hidden",
                borderRight: "1px solid var(--forge-border)",
              }}
            >
              {sidebar}
            </aside>
          )}
          <main style={{ flex: 1, overflow: "hidden" }}>
            <Outlet />
          </main>
        </div>

        <button
          onClick={() => setTerminalOpen((v) => !v)}
          style={{
            display: "flex",
            alignItems: "center",
            gap: "0.5rem",
            padding: "0.375rem 0.75rem",
            color: "var(--forge-text-secondary)",
            fontFamily: "var(--font-mono)",
            fontSize: "var(--text-xs)",
            background: "none",
            border: "none",
            borderTop: "1px solid var(--forge-border)",
            width: "100%",
            cursor: "pointer",
            transition: "background-color 150ms",
          }}
          onMouseEnter={(e) => { e.currentTarget.style.backgroundColor = "var(--forge-surface-raised)"; }}
          onMouseLeave={(e) => { e.currentTarget.style.backgroundColor = ""; }}
        >
          <TerminalIcon size={12} />
          <span>Terminal</span>
          {terminalOpen ? <ChevronDown size={12} /> : <ChevronUp size={12} />}
        </button>

        {terminalOpen && (
          <div
            style={{
              height: "300px",
              flexShrink: 0,
              overflow: "hidden",
              borderTop: "1px solid var(--forge-border)",
            }}
          >
            <Terminal sessionId="main" />
          </div>
        )}
      </div>
    </div>
  );
}