import { useState, useEffect } from "react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { HotkeyButton } from "@/components/ui/hotkey-button";
import { Input } from "@/components/ui/input";
import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
import {
  Plus,
  MessageSquare,
  Archive,
  Trash2,
  Edit2,
  Check,
  X,
  ArchiveRestore,
  Loader2,
} from "lucide-react";
import { cn } from "@/lib/utils";
import type { SessionListItem } from "@/types/electron";
import { useKeyboardShortcutsConfig } from "@/hooks/use-keyboard-shortcuts";
import { getElectronAPI } from "@/lib/electron";
import { DeleteSessionDialog } from "@/components/delete-session-dialog";
import { DeleteAllArchivedSessionsDialog } from "@/components/delete-all-archived-sessions-dialog";

// Random session name generator
const adjectives = [
  "Swift",
  "Bright",
  "Clever",
  "Dynamic",
  "Eager",
  "Focused",
  "Gentle",
  "Happy",
  "Inventive",
  "Jolly",
  "Keen",
  "Lively",
  "Mighty",
  "Noble",
  "Optimal",
  "Peaceful",
  "Quick",
  "Radiant",
  "Smart",
  "Tranquil",
  "Unique",
  "Vibrant",
  "Wise",
  "Zealous",
];

const nouns = [
  "Agent",
  "Builder",
  "Coder",
  "Developer",
  "Explorer",
  "Forge",
  "Garden",
  "Helper",
  "Innovator",
  "Journey",
  "Kernel",
  "Lighthouse",
  "Mission",
  "Navigator",
  "Oracle",
  "Project",
  "Quest",
  "Runner",
  "Spark",
  "Task",
  "Unicorn",
  "Voyage",
  "Workshop",
];

function generateRandomSessionName(): string {
  const adjective = adjectives[Math.floor(Math.random() * adjectives.length)];
  const noun = nouns[Math.floor(Math.random() * nouns.length)];
  const number = Math.floor(Math.random() * 100);
  return `${adjective} ${noun} ${number}`;
}

interface SessionManagerProps {
  currentSessionId: string | null;
  onSelectSession: (sessionId: string | null) => void;
  projectPath: string;
  isCurrentSessionThinking?: boolean;
  onQuickCreateRef?: React.MutableRefObject<(() => Promise<void>) | null>;
}

export function SessionManager({
  currentSessionId,
  onSelectSession,
  projectPath,
  isCurrentSessionThinking = false,
  onQuickCreateRef,
}: SessionManagerProps) {
  const shortcuts = useKeyboardShortcutsConfig();
  const [sessions, setSessions] = useState<SessionListItem[]>([]);
  const [activeTab, setActiveTab] = useState<"active" | "archived">("active");
  const [editingSessionId, setEditingSessionId] = useState<string | null>(null);
  const [editingName, setEditingName] = useState("");
  const [isCreating, setIsCreating] = useState(false);
  const [newSessionName, setNewSessionName] = useState("");
  const [runningSessions, setRunningSessions] = useState<Set<string>>(
    new Set()
  );
  const [isDeleteDialogOpen, setIsDeleteDialogOpen] = useState(false);
  const [sessionToDelete, setSessionToDelete] =
    useState<SessionListItem | null>(null);
  const [isDeleteAllArchivedDialogOpen, setIsDeleteAllArchivedDialogOpen] =
    useState(false);

  // Check running state for all sessions
  const checkRunningSessions = async (sessionList: SessionListItem[]) => {
    const api = getElectronAPI();
    if (!api?.agent) return;

    const runningIds = new Set<string>();

    // Check each session's running state
    for (const session of sessionList) {
      try {
        const result = await api.agent.getHistory(session.id);
        if (result.success && result.isRunning) {
          runningIds.add(session.id);
        }
      } catch (err) {
        // Ignore errors for individual session checks
        console.warn(
          `[SessionManager] Failed to check running state for ${session.id}:`,
          err
        );
      }
    }

    setRunningSessions(runningIds);
  };

  // Load sessions
  const loadSessions = async () => {
    const api = getElectronAPI();
    if (!api?.sessions) return;

    // Always load all sessions and filter client-side
    const result = await api.sessions.list(true);
    if (result.success && result.sessions) {
      setSessions(result.sessions);
      // Check running state for all sessions
      await checkRunningSessions(result.sessions);
    }
  };

  useEffect(() => {
    loadSessions();
  }, []);

  // Periodically check running state for sessions (useful for detecting when agents finish)
  useEffect(() => {
    // Only poll if there are running sessions
    if (runningSessions.size === 0 && !isCurrentSessionThinking) return;

    const interval = setInterval(async () => {
      if (sessions.length > 0) {
        await checkRunningSessions(sessions);
      }
    }, 3000); // Check every 3 seconds

    return () => clearInterval(interval);
  }, [sessions, runningSessions.size, isCurrentSessionThinking]);

  // Create new session with random name
  const handleCreateSession = async () => {
    const api = getElectronAPI();
    if (!api?.sessions) return;

    const sessionName = newSessionName.trim() || generateRandomSessionName();

    const result = await api.sessions.create(
      sessionName,
      projectPath,
      projectPath
    );

    if (result.success && result.session?.id) {
      setNewSessionName("");
      setIsCreating(false);
      await loadSessions();
      onSelectSession(result.session.id);
    }
  };

  // Create new session directly with a random name (one-click)
  const handleQuickCreateSession = async () => {
    const api = getElectronAPI();
    if (!api?.sessions) return;

    const sessionName = generateRandomSessionName();

    const result = await api.sessions.create(
      sessionName,
      projectPath,
      projectPath
    );

    if (result.success && result.session?.id) {
      await loadSessions();
      onSelectSession(result.session.id);
    }
  };

  // Expose the quick create function via ref for keyboard shortcuts
  useEffect(() => {
    if (onQuickCreateRef) {
      onQuickCreateRef.current = handleQuickCreateSession;
    }
    return () => {
      if (onQuickCreateRef) {
        onQuickCreateRef.current = null;
      }
    };
  }, [onQuickCreateRef, projectPath]);

  // Rename session
  const handleRenameSession = async (sessionId: string) => {
    const api = getElectronAPI();
    if (!editingName.trim() || !api?.sessions) return;

    const result = await api.sessions.update(sessionId, editingName, undefined);

    if (result.success) {
      setEditingSessionId(null);
      setEditingName("");
      await loadSessions();
    }
  };

  // Archive session
  const handleArchiveSession = async (sessionId: string) => {
    const api = getElectronAPI();
    if (!api?.sessions) {
      console.error("[SessionManager] Sessions API not available");
      return;
    }

    try {
      const result = await api.sessions.archive(sessionId);
      if (result.success) {
        // If the archived session was currently selected, deselect it
        if (currentSessionId === sessionId) {
          onSelectSession(null);
        }
        await loadSessions();
      } else {
        console.error("[SessionManager] Archive failed:", result.error);
      }
    } catch (error) {
      console.error("[SessionManager] Archive error:", error);
    }
  };

  // Unarchive session
  const handleUnarchiveSession = async (sessionId: string) => {
    const api = getElectronAPI();
    if (!api?.sessions) {
      console.error("[SessionManager] Sessions API not available");
      return;
    }

    try {
      const result = await api.sessions.unarchive(sessionId);
      if (result.success) {
        await loadSessions();
      } else {
        console.error("[SessionManager] Unarchive failed:", result.error);
      }
    } catch (error) {
      console.error("[SessionManager] Unarchive error:", error);
    }
  };

  // Open delete session dialog
  const handleDeleteSession = (session: SessionListItem) => {
    setSessionToDelete(session);
    setIsDeleteDialogOpen(true);
  };

  // Confirm delete session
  const confirmDeleteSession = async (sessionId: string) => {
    const api = getElectronAPI();
    if (!api?.sessions) return;

    const result = await api.sessions.delete(sessionId);
    if (result.success) {
      await loadSessions();
      if (currentSessionId === sessionId) {
        // Switch to another session or create a new one
        const activeSessionsList = sessions.filter((s) => !s.isArchived);
        if (activeSessionsList.length > 0) {
          onSelectSession(activeSessionsList[0].id);
        }
      }
    }
    setSessionToDelete(null);
  };

  // Delete all archived sessions
  const handleDeleteAllArchivedSessions = async () => {
    const api = getElectronAPI();
    if (!api?.sessions) return;

    // Delete each archived session
    for (const session of archivedSessions) {
      await api.sessions.delete(session.id);
    }

    await loadSessions();
    setIsDeleteAllArchivedDialogOpen(false);
  };

  const activeSessions = sessions.filter((s) => !s.isArchived);
  const archivedSessions = sessions.filter((s) => s.isArchived);
  const displayedSessions =
    activeTab === "active" ? activeSessions : archivedSessions;

  return (
    <Card className="h-full flex flex-col rounded-none">
      <CardHeader className="pb-3">
        <div className="flex items-center justify-between mb-4">
          <CardTitle>Agent Sessions</CardTitle>
          <HotkeyButton
            variant="default"
            size="sm"
            onClick={() => {
              // Switch to active tab if on archived tab
              if (activeTab === "archived") {
                setActiveTab("active");
              }
              handleQuickCreateSession();
            }}
            hotkey={shortcuts.newSession}
            hotkeyActive={false}
            data-testid="new-session-button"
            title={`New Session (${shortcuts.newSession})`}
          >
            <Plus className="w-4 h-4 mr-1" />
            New
          </HotkeyButton>
        </div>

        <Tabs
          value={activeTab}
          onValueChange={(value) =>
            setActiveTab(value as "active" | "archived")
          }
          className="w-full"
        >
          <TabsList className="w-full">
            <TabsTrigger value="active" className="flex-1">
              <MessageSquare className="w-4 h-4 mr-2" />
              Active ({activeSessions.length})
            </TabsTrigger>
            <TabsTrigger value="archived" className="flex-1">
              <Archive className="w-4 h-4 mr-2" />
              Archived ({archivedSessions.length})
            </TabsTrigger>
          </TabsList>
        </Tabs>
      </CardHeader>

      <CardContent
        className="flex-1 overflow-y-auto space-y-2"
        data-testid="session-list"
      >
        {/* Create new session */}
        {isCreating && (
          <div className="p-3 border rounded-lg bg-muted/50">
            <div className="flex gap-2">
              <Input
                placeholder="Session name..."
                value={newSessionName}
                onChange={(e) => setNewSessionName(e.target.value)}
                onKeyDown={(e) => {
                  if (e.key === "Enter") handleCreateSession();
                  if (e.key === "Escape") {
                    setIsCreating(false);
                    setNewSessionName("");
                  }
                }}
                autoFocus
              />
              <Button size="sm" onClick={handleCreateSession}>
                <Check className="w-4 h-4" />
              </Button>
              <Button
                size="sm"
                variant="ghost"
                onClick={() => {
                  setIsCreating(false);
                  setNewSessionName("");
                }}
              >
                <X className="w-4 h-4" />
              </Button>
            </div>
          </div>
        )}

        {/* Delete All Archived button - shown at the top of archived sessions */}
        {activeTab === "archived" && archivedSessions.length > 0 && (
          <div className="pb-2 border-b mb-2">
            <Button
              variant="destructive"
              size="sm"
              className="w-full"
              onClick={() => setIsDeleteAllArchivedDialogOpen(true)}
              data-testid="delete-all-archived-sessions-button"
            >
              <Trash2 className="w-4 h-4 mr-2" />
              Delete All Archived Sessions
            </Button>
          </div>
        )}

        {/* Session list */}
        {displayedSessions.map((session) => (
          <div
            key={session.id}
            className={cn(
              "p-3 border rounded-lg cursor-pointer transition-colors hover:bg-accent/50",
              currentSessionId === session.id && "bg-primary/10 border-primary",
              session.isArchived && "opacity-60"
            )}
            onClick={() => !session.isArchived && onSelectSession(session.id)}
            data-testid={`session-item-${session.id}`}
          >
            <div className="flex items-start justify-between gap-2">
              <div className="flex-1 min-w-0">
                {editingSessionId === session.id ? (
                  <div className="flex gap-2 mb-2">
                    <Input
                      value={editingName}
                      onChange={(e) => setEditingName(e.target.value)}
                      onKeyDown={(e) => {
                        if (e.key === "Enter") handleRenameSession(session.id);
                        if (e.key === "Escape") {
                          setEditingSessionId(null);
                          setEditingName("");
                        }
                      }}
                      onClick={(e) => e.stopPropagation()}
                      autoFocus
                      className="h-7"
                    />
                    <Button
                      size="sm"
                      onClick={(e) => {
                        e.stopPropagation();
                        handleRenameSession(session.id);
                      }}
                      className="h-7"
                    >
                      <Check className="w-3 h-3" />
                    </Button>
                    <Button
                      size="sm"
                      variant="ghost"
                      onClick={(e) => {
                        e.stopPropagation();
                        setEditingSessionId(null);
                        setEditingName("");
                      }}
                      className="h-7"
                    >
                      <X className="w-3 h-3" />
                    </Button>
                  </div>
                ) : (
                  <>
                    <div className="flex items-center gap-2 mb-1">
                      {/* Show loading indicator if this session is running (either current session thinking or any session in runningSessions) */}
                      {(currentSessionId === session.id &&
                        isCurrentSessionThinking) ||
                      runningSessions.has(session.id) ? (
                        <Loader2 className="w-4 h-4 text-primary animate-spin shrink-0" />
                      ) : (
                        <MessageSquare className="w-4 h-4 text-muted-foreground shrink-0" />
                      )}
                      <h3 className="font-medium truncate">{session.name}</h3>
                      {((currentSessionId === session.id &&
                        isCurrentSessionThinking) ||
                        runningSessions.has(session.id)) && (
                        <span className="text-xs text-primary bg-primary/10 px-2 py-0.5 rounded-full">
                          thinking...
                        </span>
                      )}
                    </div>
                    {session.preview && (
                      <p className="text-xs text-muted-foreground truncate">
                        {session.preview}
                      </p>
                    )}
                    <div className="flex items-center gap-2 mt-2">
                      <span className="text-xs text-muted-foreground">
                        {session.messageCount} messages
                      </span>
                      <span className="text-xs text-muted-foreground">·</span>
                      <span className="text-xs text-muted-foreground">
                        {new Date(session.updatedAt).toLocaleDateString()}
                      </span>
                    </div>
                  </>
                )}
              </div>

              {/* Actions */}
              {!session.isArchived && (
                <div
                  className="flex gap-1"
                  onClick={(e) => e.stopPropagation()}
                >
                  <Button
                    size="sm"
                    variant="ghost"
                    onClick={() => {
                      setEditingSessionId(session.id);
                      setEditingName(session.name);
                    }}
                    className="h-7 w-7 p-0"
                  >
                    <Edit2 className="w-3 h-3" />
                  </Button>
                  <Button
                    size="sm"
                    variant="ghost"
                    onClick={() => handleArchiveSession(session.id)}
                    className="h-7 w-7 p-0"
                    data-testid={`archive-session-${session.id}`}
                  >
                    <Archive className="w-3 h-3" />
                  </Button>
                </div>
              )}

              {session.isArchived && (
                <div
                  className="flex gap-1"
                  onClick={(e) => e.stopPropagation()}
                >
                  <Button
                    size="sm"
                    variant="ghost"
                    onClick={() => handleUnarchiveSession(session.id)}
                    className="h-7 w-7 p-0"
                  >
                    <ArchiveRestore className="w-3 h-3" />
                  </Button>
                  <Button
                    size="sm"
                    variant="ghost"
                    onClick={() => handleDeleteSession(session)}
                    className="h-7 w-7 p-0 text-destructive"
                    data-testid={`delete-session-${session.id}`}
                  >
                    <Trash2 className="w-3 h-3" />
                  </Button>
                </div>
              )}
            </div>
          </div>
        ))}

        {displayedSessions.length === 0 && (
          <div className="text-center py-8 text-muted-foreground">
            <MessageSquare className="w-12 h-12 mx-auto mb-2 opacity-50" />
            <p className="text-sm">
              {activeTab === "active"
                ? "No active sessions"
                : "No archived sessions"}
            </p>
            <p className="text-xs">
              {activeTab === "active"
                ? "Create your first session to get started"
                : "Archive sessions to see them here"}
            </p>
          </div>
        )}
      </CardContent>

      {/* Delete Session Confirmation Dialog */}
      <DeleteSessionDialog
        open={isDeleteDialogOpen}
        onOpenChange={setIsDeleteDialogOpen}
        session={sessionToDelete}
        onConfirm={confirmDeleteSession}
      />

      {/* Delete All Archived Sessions Confirmation Dialog */}
      <DeleteAllArchivedSessionsDialog
        open={isDeleteAllArchivedDialogOpen}
        onOpenChange={setIsDeleteAllArchivedDialogOpen}
        archivedCount={archivedSessions.length}
        onConfirm={handleDeleteAllArchivedSessions}
      />
    </Card>
  );
}