// Author: Shiv
// Date: April 2026

"use client";

import { useState, useRef, useEffect } from "react";
import Link from "next/link";
import { usePathname } from "next/navigation";
import { useAuth } from "@/context/AuthContext";
import { useChatWidget } from "@/context/ChatWidgetContext";

//Floating chat button and popup window - handles AI chat, live support, and conversation history
export default function FloatingChat() {
  const pathname = usePathname();
  const { user, token } = useAuth();
  const {
    isOpen, toggleOpen,
    view, openView,
    aiMessages, aiSending, aiError, setAiError, sendAiMessage,
    conversations, convsLoading, loadConversations,
    activeConvId, activeConv, liveMessages, liveSending,
    openLiveConversation, sendLiveMessage,
    startLiveChat, switchingToHuman,
  } = useChatWidget();

  const [input, setInput] = useState("");
  const [fabHovered, setFabHovered] = useState(false);
  const messagesEndRef = useRef(null);
 const prevAiLengthRef = useRef(0);
const prevLiveLengthRef = useRef(0);  

  //Scrolls to the bottom when new messages arrive, but only if already near the bottom
  useEffect(() => {
  if (!isOpen) return;
  const aiGrew = aiMessages.length > prevAiLengthRef.current;
  const liveGrew = liveMessages.length > prevLiveLengthRef.current;
  prevAiLengthRef.current = aiMessages.length;
  prevLiveLengthRef.current = liveMessages.length;
  if (aiGrew || liveGrew) {
    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
  }
}, [aiMessages, liveMessages, isOpen]);


  useEffect(() => {
    if (view === "history" && token && isOpen) loadConversations(token);
  }, [view, token, isOpen, loadConversations]);

  //Don't show the widget on the full chat pages since they have their own UI
  if (pathname === "/ai-chat" || pathname === "/chat") return null;

  const openConvCount = conversations.filter((c) => c.status === "OPEN").length;
  const isLiveClosed  = activeConv?.status === "CLOSED";

  //Sends the typed message to whichever chat is currently active
  async function handleSend(e) {
    e?.preventDefault();
    const text = input.trim();
    if (!text) return;
    setInput("");
    if (view === "ai") {
      await sendAiMessage(text, token);
    } else if (view === "live" && activeConvId) {
      await sendLiveMessage(text, token, activeConvId);
    }
  }

  function handleKeyDown(e) {
    if (e.key === "Enter" && !e.shiftKey) { e.preventDefault(); handleSend(); }
  }

  return (
    <>
      {/* Floating toggle button */}
      <button onClick={toggleOpen} style={s.fab} aria-label={isOpen ? "Close chat" : "Open chat"} onMouseEnter={() => setFabHovered(true)} onMouseLeave={() => setFabHovered(false)}>
        {isOpen ? (
          <span style={{ fontSize: "1.4rem", lineHeight: 1 }}>✕</span>
        ) : (
          <span style={{ position: "relative", width: 24, height: 24, display: "inline-block" }}>
            <img src="/bootstrap/chat.svg" alt="" style={{ width: 24, height: 24, position: "absolute", inset: 0, filter: "brightness(0) invert(1)", opacity: fabHovered ? 0 : 1, transition: "opacity 0.15s" }} />
            <img src="/bootstrap/chat-fill.svg" alt="" style={{ width: 24, height: 24, position: "absolute", inset: 0, filter: "brightness(0) invert(1)", opacity: fabHovered ? 1 : 0, transition: "opacity 0.15s" }} />
          </span>
        )}
        {!isOpen && openConvCount > 0 && <span style={s.fabBadge}>{openConvCount}</span>}
      </button>

      {/* Chat window */}
      {isOpen && (
        <div style={s.window}>

          {/* Header */}
          <div style={s.header}>
            <div style={s.headerLeft}>
              <div style={s.headerAvatar}><img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "100%", height: "100%", filter: "brightness(0) invert(1)" }} /></div>
              <div>
                <div style={s.headerTitle}>Leon's Assistant</div>
                <div style={s.headerSub}>
                  {view === "live"
                    ? (activeConv?.mode === "HUMAN" ? "Live Support" : "AI Support")
                    : view === "history" ? "Your Conversations"
                    : "AI Chat"}
                </div>
              </div>
            </div>
            <div style={s.headerRight}>
              {view !== "ai" && (
                <button style={s.headerNavBtn} onClick={() => openView("ai")}>AI</button>
              )}
              <button style={s.headerClose} onClick={toggleOpen} aria-label="Close">✕</button>
            </div>
          </div>

          {/* Guest */}
          {!user && (
            <div style={s.guestBody}>
              <img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "2.5rem", height: "2.5rem", opacity: 0.6 }} />
              <p style={{ color: "#555", fontSize: "0.95rem", margin: "0.75rem 0 1.25rem", textAlign: "center" }}>
                Log in to chat with our pet assistant!
              </p>
              <Link href="/login" style={s.loginBtn} onClick={toggleOpen}>Log In</Link>
            </div>
          )}

          {/* History view */}
          {user && view === "history" && (
            <div style={{ flex: 1, overflowY: "auto", display: "flex", flexDirection: "column" }}>
              <div style={s.historyToolbar}>
                <button
                  style={{ ...s.newChatBtn, ...(switchingToHuman ? s.disabledBtn : {}) }}
                  onClick={() => startLiveChat(token)}
                  disabled={switchingToHuman}
                >
                  {switchingToHuman ? "Starting…" : "+ New Live Chat"}
                </button>
                <button style={s.aiTabBtn} onClick={() => openView("ai")}>AI Chat</button>
              </div>

              {convsLoading && (
                <p style={{ color: "#aaa", fontSize: "0.85rem", padding: "1.25rem", textAlign: "center" }}>
                  Loading…
                </p>
              )}

              {!convsLoading && conversations.length === 0 && (
                <div style={{ ...s.empty, flex: 1 }}>
                  <img src="/bootstrap/chat.svg" alt="chat" style={{ width: 32, height: 32, opacity: 0.5 }} />
                  <p style={s.emptyText}>No conversations yet.<br />Start a live chat above.</p>
                </div>
              )}


              {/*open & active conversations*/}
              {conversations.filter(c => c.status === "OPEN" && c.staffId).length > 0 && (
                <div style={s.sectionLabel}> Active 
                </div>
              )}
              {conversations.filter(c => c.status === "OPEN" && c.staffId).map((conv) => (
                <button key={conv.id} style={s.convItem} onClick={() => openLiveConversation(conv.id, token)}>
                  <div style={s.convTop}>
                    <span style={s.convSubject}>{conv.subject || `Conversation #${conv.id}`}</span>
                     <span style={{ ...s.statusBadge, ...s.statusOpen }}>Active</span>
                  </div>
                  <div style={s.convBottom}>
                    <span style={s.convMode}>Live Support</span>
                    <span style={s.convDate}>{conv.createdAt ? new Date(conv.createdAt).toLocaleDateString() : ""}</span>
                  </div>

                </button>


            
          ))}

          {/* Unclaimed - waiting for staff */}
          {conversations.filter(c => c.status === "OPEN" && !c.staffId).length > 0 && (
            <div style={s.sectionLabel}> Waiting </div>
          )}
          {conversations.filter(c => c.status === "OPEN" && !c.staffId).map((conv) => (
            <button key={conv.id} style={s.convItem} onClick={() => openLiveConversation(conv.id, token)}>
            <div style={s.convTop}>
               <span style={s.convSubject}>{conv.subject || `Conversation #${conv.id}`}</span>
               <span style={{ ...s.statusBadge, ...s.statusUnclaimed }}>Waiting</span>
              </div> 
              <div style={s.convBottom}>
                <span style={s.convMode}>⏳ Waiting for agent</span>
                <span style={s.convDate}>{conv.createdAt ? new Date(conv.createdAt).toLocaleDateString() : ""}</span>
    
                </div> 

            </button>

          ))}

          {/* Closed convesations*/}
          {conversations.filter(c => c.status === "CLOSED").length > 0 && (
            <div style={s.sectionLabel}> Closed</div>
          )}
          {conversations.filter(c => c.status === "CLOSED").map((conv) => (
            <button key={conv.id} style={{ ...s.convItem, ...s.convItemClosed }} onClick={() => openLiveConversation(conv.id, token)}>
             <div style={s.convTop}>
               <span style={{ ...s.convSubject, color: "#aaa" }}>{conv.subject || `Conversation #${conv.id}`}</span>
               <span style={{ ...s.statusBadge, ...s.statusClosed }}>Closed</span>
               </div> 
            </button>
          ))}

          </div>
          )}



          {/* Live chat view */}
          {user && view === "live" && (
            <>
              {activeConv && (
                <div style={s.liveStatus}>
                  <span style={{ ...s.statusBadge, ...(activeConv.status === "OPEN" ? s.statusOpen : s.statusClosed) }}>
                    {activeConv.status}
                  </span>
                  <span style={s.convMode}>
                    {activeConv.mode === "HUMAN" ? "👤 Live Support" : "🤖 AI Support"}
                  </span>
                  <Link href={`/chat?id=${activeConvId}`} style={s.fullPageLink} onClick={toggleOpen}>
                    Full page ↗
                  </Link>
                </div>
              )}

              <div style={s.messages}>
                {liveMessages.length === 0 && (
                  <div style={s.empty}>
                    <p style={{ color: "#aaa", fontSize: "0.85rem" }}>No messages yet.</p>
                  </div>
                )}
                {liveMessages.map((msg) => {
                  const isUser = msg.senderRole === "CUSTOMER";
                  return (
                    <div key={msg.id} style={{ ...s.row, ...(isUser ? s.rowUser : s.rowOther) }}>
                      {!isUser && (
                        <div style={s.otherAvatar}><img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "100%", height: "100%" }} /></div>
                      )}
                      <div style={{ ...s.bubble, ...(isUser ? s.bubbleUser : s.bubbleOther) }}>
                        {!isUser && (
                          <div style={s.senderName}>
                            {msg.senderName || (msg.senderRole === "BOT" ? "AI Bot" : "Staff")}
                          </div>
                        )}
                        {msg.content}
                      </div>
                      {isUser && (
                        <div style={s.userAvatar}>
                          {user?.fullName ? user.fullName.charAt(0).toUpperCase() : "U"}
                        </div>
                      )}
                    </div>
                  );
                })}
                <div ref={messagesEndRef} />
              </div>

              {isLiveClosed ? (
                <div style={s.closedBanner}>This conversation is closed.</div>
              ) : (
                <form style={s.inputRow} onSubmit={handleSend}>
                  <input
                    style={s.input}
                    value={input}
                    onChange={(e) => setInput(e.target.value)}
                    onKeyDown={handleKeyDown}
                    placeholder="Type a message…"
                    disabled={liveSending}
                    autoComplete="off"
                  />
                  <button type="submit"
                    style={{ ...s.sendBtn, ...(!input.trim() || liveSending ? s.sendBtnDisabled : {}) }}
                    disabled={!input.trim() || liveSending}>➤</button>
                </form>
              )}
            </>
          )}

          {/* AI chat view */}
          {user && view === "ai" && (
            <>
              <div style={s.toolbar}>
                <Link href="/ai-chat" style={s.fullPageLink} onClick={toggleOpen}>Open full page ↗</Link>
                <button
                  style={{ ...s.humanBtn, ...(switchingToHuman ? s.disabledBtn : {}) }}
                  onClick={() => startLiveChat(token)}
                  disabled={switchingToHuman}
                >
                  {switchingToHuman ? "Connecting…" : "Chat with a human"}
                </button>
              </div>

              <div style={s.messages}>
                {aiMessages.length === 0 && (
                  <div style={s.empty}>
                    <img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "2rem", height: "2rem", opacity: 0.5 }} />
                    <p style={s.emptyText}>
                      Hi{user?.fullName ? `, ${user.fullName.split(" ")[0]}` : ""}!<br />
                      Ask me anything about pets.
                    </p>
                  </div>
                )}

                {aiMessages.map((msg) => (
                  <div key={msg.id} style={{ ...s.row, ...(msg.role === "user" ? s.rowUser : s.rowOther) }}>
                    {msg.role === "assistant" && <div style={s.otherAvatar}><img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "100%", height: "100%" }} /></div>}
                    <div style={{ ...s.bubble, ...(msg.role === "user" ? s.bubbleUser : s.bubbleOther) }}>
                      {msg.content.split("\n").map((line, i, arr) => (
                        <span key={i}>{line}{i < arr.length - 1 && <br />}</span>
                      ))}
                    </div>
                    {msg.role === "user" && (
                      <div style={s.userAvatar}>
                        {user?.fullName ? user.fullName.charAt(0).toUpperCase() : "U"}
                      </div>
                    )}
                  </div>
                ))}

                {aiSending && (
                  <div style={{ ...s.row, ...s.rowOther }}>
                    <div style={s.otherAvatar}><img src="/bootstrap/person-circle.svg" alt="assistant" style={{ width: "100%", height: "100%" }} /></div>
                    <div style={{ ...s.bubble, ...s.bubbleOther, ...s.typingBubble }}>
                      <span className="fc-dot" />
                      <span className="fc-dot" style={{ animationDelay: "0.2s" }} />
                      <span className="fc-dot" style={{ animationDelay: "0.4s" }} />
                    </div>
                  </div>
                )}

                {aiError && (
                  <div style={s.errorBar}>
                    {aiError}
                    <button style={s.errorClose} onClick={() => setAiError(null)}>✕</button>
                  </div>
                )}

                <div ref={messagesEndRef} />
              </div>

              <form style={s.inputRow} onSubmit={handleSend}>
                <input
                  style={s.input}
                  value={input}
                  onChange={(e) => setInput(e.target.value)}
                  onKeyDown={handleKeyDown}
                  placeholder="Ask about pet care…"
                  disabled={aiSending}
                  autoComplete="off"
                />
                <button type="submit"
                  style={{ ...s.sendBtn, ...(!input.trim() || aiSending ? s.sendBtnDisabled : {}) }}
                  disabled={!input.trim() || aiSending}>➤</button>
              </form>
            </>
          )}

        </div>
      )}
    </>
  );
}

//Inline style objects for the floating chat widget
const s = {
  fab: {
    position: "fixed", bottom: 24, right: 24,
    width: 56, height: 56, borderRadius: "50%",
    background: "#e68672", color: "#2f2f2f", border: "none",
    cursor: "pointer", zIndex: 9999,
    boxShadow: "0 4px 18px rgba(0,0,0,0.22)",
    display: "flex", alignItems: "center", justifyContent: "center",
    transition: "transform 0.15s, box-shadow 0.15s",
  },
  fabBadge: {
    position: "absolute", top: 2, right: 2,
    background: "#e53935", color: "white",
    borderRadius: "999px", fontSize: "0.62rem", fontWeight: 700,
    minWidth: 17, height: 17,
    display: "flex", alignItems: "center", justifyContent: "center", padding: "0 3px",
  },
  window: {
    position: "fixed", bottom: 92, right: 24,
    width: 370, height: 530,
    background: "#fff", borderRadius: 16,
    boxShadow: "0 8px 36px rgba(0,0,0,0.18)",
    zIndex: 9998, display: "flex", flexDirection: "column",
    overflow: "hidden", fontFamily: "Arial, sans-serif",
  },
  header: {
    background: "#e68672", padding: "0.8rem 1rem",
    display: "flex", alignItems: "center", justifyContent: "space-between", flexShrink: 0,
  },
  headerLeft:  { display: "flex", alignItems: "center", gap: "0.6rem" },
  headerAvatar: {
    width: 36, height: 36, borderRadius: "50%",
    background: "rgba(255,255,255,0.25)",
    display: "flex", alignItems: "center", justifyContent: "center", fontSize: "1.1rem",
  },
  headerTitle: { fontWeight: 700, fontSize: "0.92rem", color: "#2f2f2f" },
  headerSub:   { fontSize: "0.7rem", color: "rgba(47,47,47,0.65)", marginTop: 1 },
  headerRight: { display: "flex", alignItems: "center", gap: "0.35rem" },
  headerNavBtn: {
    background: "rgba(255,255,255,0.22)", border: "none", borderRadius: 6,
    padding: "0.28rem 0.6rem", fontSize: "0.75rem", fontWeight: 600,
    color: "#2f2f2f", cursor: "pointer",
  },
  headerNavBtnActive: { background: "rgba(255,255,255,0.45)" },
  headerClose: {
    background: "transparent", border: "none",
    fontSize: "0.95rem", color: "#2f2f2f", cursor: "pointer", padding: "0.2rem 0.35rem", lineHeight: 1,
  },
  guestBody: {
    flex: 1, display: "flex", flexDirection: "column",
    alignItems: "center", justifyContent: "center", padding: "2rem",
  },
  loginBtn: {
    background: "#e68672", color: "#2f2f2f",
    padding: "0.6rem 1.5rem", borderRadius: 8,
    textDecoration: "none", fontWeight: 700, fontSize: "0.95rem",
  },
  toolbar: {
    display: "flex", alignItems: "center", justifyContent: "space-between",
    padding: "0.5rem 0.85rem", borderBottom: "1px solid #f0f0f0",
    background: "#fafafa", flexShrink: 0,
  },
  fullPageLink: { color: "#e68672", fontSize: "0.76rem", fontWeight: 600, textDecoration: "none" },
  humanBtn: {
    background: "transparent", border: "1.5px solid #e68672", color: "#e68672",
    borderRadius: 6, padding: "0.28rem 0.65rem", fontSize: "0.76rem", fontWeight: 600, cursor: "pointer",
  },
  disabledBtn: { opacity: 0.55, cursor: "not-allowed" },
  messages: {
    flex: 1, overflowY: "auto", padding: "0.8rem",
    display: "flex", flexDirection: "column", gap: "0.55rem",
  },
  empty: {
    flex: 1, display: "flex", flexDirection: "column",
    alignItems: "center", justifyContent: "center", gap: "0.5rem", margin: "auto",
  },
  emptyText: { color: "#aaa", fontSize: "0.88rem", textAlign: "center", lineHeight: 1.5, margin: 0 },
  row:      { display: "flex", alignItems: "flex-end", gap: "0.4rem" },
  rowUser:  { flexDirection: "row-reverse" },
  rowOther: { flexDirection: "row" },
  otherAvatar: {
    width: 26, height: 26, borderRadius: "50%", background: "#f0f0f0",
    display: "flex", alignItems: "center", justifyContent: "center",
    fontSize: "0.75rem", flexShrink: 0,
  },
  userAvatar: {
    width: 26, height: 26, borderRadius: "50%", background: "#e68672", color: "#2f2f2f",
    display: "flex", alignItems: "center", justifyContent: "center",
    fontSize: "0.72rem", fontWeight: 700, flexShrink: 0,
  },
  bubble: {
    maxWidth: "76%", padding: "0.5rem 0.75rem", borderRadius: 12,
    fontSize: "0.86rem", lineHeight: 1.5, wordBreak: "break-word",
  },
  bubbleUser:   { background: "#e68672", color: "#2f2f2f", borderBottomRightRadius: 4 },
  bubbleOther:  { background: "#f4f4f4", color: "#1a1a1a", borderBottomLeftRadius: 4 },
  typingBubble: { display: "flex", alignItems: "center", gap: "4px", padding: "0.65rem 0.85rem" },
  senderName:   { fontSize: "0.7rem", fontWeight: 700, color: "#888", marginBottom: 2 },
  errorBar: {
    background: "#fff0f0", borderTop: "1px solid #ffd0d0", color: "#c0392b",
    padding: "0.5rem 0.85rem", fontSize: "0.8rem",
    display: "flex", alignItems: "center", justifyContent: "space-between", flexShrink: 0,
  },
  errorClose: { background: "none", border: "none", color: "#c0392b", cursor: "pointer" },
  inputRow: {
    display: "flex", gap: "0.45rem", padding: "0.6rem 0.85rem",
    borderTop: "1px solid #f0f0f0", flexShrink: 0,
  },
  input: {
    flex: 1, border: "1.5px solid #e0e0e0", borderRadius: 8,
    padding: "0.48rem 0.75rem", fontSize: "0.86rem", outline: "none", fontFamily: "inherit",
  },
  sendBtn: {
    background: "#e68672", color: "#2f2f2f", border: "none", borderRadius: 8,
    padding: "0.48rem 0.75rem", fontSize: "0.95rem", fontWeight: 700, cursor: "pointer", flexShrink: 0,
  },
  sendBtnDisabled: { background: "#f0c8be", cursor: "not-allowed" },
  historyToolbar: {
    display: "flex", gap: "0.5rem", padding: "0.65rem 0.85rem",
    borderBottom: "1px solid #f0f0f0", flexShrink: 0,
  },
  newChatBtn: {
    flex: 1, background: "#e68672", color: "#2f2f2f", border: "none",
    borderRadius: 8, padding: "0.5rem", fontSize: "0.8rem", fontWeight: 700, cursor: "pointer",
  },
  aiTabBtn: {
    background: "#f4f4f4", color: "#555", border: "none", borderRadius: 8,
    padding: "0.5rem 0.85rem", fontSize: "0.8rem", fontWeight: 600, cursor: "pointer",
  },
  convItem: {
    display: "flex", flexDirection: "column", gap: "0.2rem",
    padding: "0.7rem 0.85rem", borderBottom: "1px solid #f0f0f0",
    background: "white", border: "none", textAlign: "left", cursor: "pointer", width: "100%",
  },
  convTop:    { display: "flex", alignItems: "center", justifyContent: "space-between", gap: "0.5rem" },
  convBottom: { display: "flex", alignItems: "center", justifyContent: "space-between" },
  convSubject: {
    fontSize: "0.86rem", fontWeight: 600, color: "#222",
    overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap", flex: 1,
  },
  convMode:  { fontSize: "0.74rem", color: "#999" },
  convDate:  { fontSize: "0.7rem", color: "#bbb" },
  statusBadge: {
    fontSize: "0.67rem", fontWeight: 700, borderRadius: 20,
    padding: "0.13rem 0.5rem", flexShrink: 0,
    textTransform: "uppercase", letterSpacing: "0.04em",
  },
  statusOpen:   { background: "#e6f9ee", color: "#1a7a3c" },
  statusClosed: { background: "#f0f0f0", color: "#888" },
  liveStatus: {
    display: "flex", alignItems: "center", gap: "0.5rem",
    padding: "0.45rem 0.85rem", borderBottom: "1px solid #f0f0f0",
    background: "#fafafa", flexShrink: 0,
  },
  statusUnclaimed: { background: "#fff8e1", color: "#f57f17" },
  sectionLabel: {
    fontSize: "0.7rem", fontWeight: 700, color: "#aaa",
    padding: "0.4rem 0.85rem 0.2rem", textTransform: "uppercase",
    letterSpacing: "0.05em", background: "#fafafa",
  },

convItemClosed: { background: "#fafafa", opacity: 0.75 },
  closedBanner: {
    background: "#f5f5f5", borderTop: "1px solid #e0e0e0", color: "#888",
    padding: "0.65rem 0.85rem", fontSize: "0.84rem", textAlign: "center", flexShrink: 0,
  },
};