import { useCallback, useEffect, useMemo, useRef, useState } from "react";
import { Activity, Download, Pencil, Save, Shield, Upload, X } from "lucide-react";
import type { NodeInfo, NodeUpdateInput, ProjectInfo } from "../api";
import type { ToastType } from "../hooks/useToast";
import { getProjectsForNode } from "../utils/nodeProjectAssignment";
import type { ComputedNodeSyncStatus } from "../hooks/useNodeSettingsSync";
import { formatRelativeTime } from "../hooks/useNodeSettingsSync";
import { SettingsSyncLog } from "./SettingsSyncLog";
import type { SyncLogEntry } from "./SettingsSyncLog";
import { SettingsSyncConflictModal } from "./SettingsSyncConflictModal";
import type { SettingsConflictEntry, ConflictResolutionResult } from "./SettingsSyncConflictModal";
import "./NodeDetailModal.css";

interface NodeDetailModalProps {
  isOpen: boolean;
  onClose: () => void;
  node: NodeInfo | null;
  projects: ProjectInfo[];
  onUpdate: (id: string, updates: NodeUpdateInput) => Promise<void>;
  onHealthCheck: (id: string) => Promise<void>;
  addToast: (message: string, type?: ToastType) => void;
  syncStatus?: ComputedNodeSyncStatus;
  onPushSettings?: (nodeId: string) => Promise<unknown>;
  onPullSettings?: (nodeId: string) => Promise<unknown>;
  onSyncAuth?: (nodeId: string) => Promise<unknown>;
  /** Sync history entries for this node */
  syncHistory?: SyncLogEntry[];
  /** Called when sync conflicts need resolution */
  onResolveConflicts?: (resolutions: ConflictResolutionResult[]) => Promise<void>;
}

function formatTimestamp(value?: string): string {
  if (!value) return "—";
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) return "—";
  return date.toLocaleString();
}

function getSyncStateDotClass(syncState: ComputedNodeSyncStatus["syncState"]): string {
  switch (syncState) {
    case "synced":
      return "node-detail-modal__sync-dot--synced";
    case "diff":
      return "node-detail-modal__sync-dot--diff";
    case "error":
      return "node-detail-modal__sync-dot--error";
    case "pending":
      return "node-detail-modal__sync-dot--pending";
    case "never-synced":
    default:
      return "node-detail-modal__sync-dot--never";
  }
}

export function NodeDetailModal({
  isOpen,
  onClose,
  node,
  projects,
  onUpdate,
  onHealthCheck,
  addToast,
  syncStatus,
  onPushSettings,
  onPullSettings,
  onSyncAuth,
  syncHistory = [],
  onResolveConflicts,
}: NodeDetailModalProps) {
  const isMountedRef = useRef(true);
  const [editMode, setEditMode] = useState(false);
  const [name, setName] = useState("");
  const [url, setUrl] = useState("");
  const [apiKey, setApiKey] = useState("");
  const [maxConcurrent, setMaxConcurrent] = useState(2);
  const [isSaving, setIsSaving] = useState(false);

  // Sync action states
  const [isPushing, setIsPushing] = useState(false);
  const [isPulling, setIsPulling] = useState(false);
  const [isSyncingAuth, setIsSyncingAuth] = useState(false);
  const [syncError, setSyncError] = useState<string | null>(null);

  // Conflict resolution modal state
  const [showConflictModal, setShowConflictModal] = useState(false);
  const [conflicts] = useState<SettingsConflictEntry[]>([]);
  const [dockerStatus, setDockerStatus] = useState<"running" | "stopped" | "recreating">("running");
  const [dockerEnv, setDockerEnv] = useState("FUSION_LOG_LEVEL=info");
  const [dockerMounts, setDockerMounts] = useState("/srv/fusion:/data:rw");

  useEffect(() => {
    isMountedRef.current = true;
    return () => {
      isMountedRef.current = false;
    };
  }, []);

  useEffect(() => {
    if (!node || !isOpen) {
      setEditMode(false);
      return;
    }

    setName(node.name);
    setUrl(node.url ?? "");
    setApiKey(node.apiKey ?? "");
    setMaxConcurrent(node.maxConcurrent);
    setEditMode(false);
  }, [isOpen, node]);

  useEffect(() => {
    if (!isOpen) return;

    const handleKeyDown = (event: KeyboardEvent) => {
      if (event.key === "Escape") {
        event.preventDefault();
        onClose();
      }
    };

    document.addEventListener("keydown", handleKeyDown);
    return () => document.removeEventListener("keydown", handleKeyDown);
  }, [isOpen, onClose]);

  const assignedProjects = useMemo(() => {
    if (!node) return [];
    return getProjectsForNode(projects, node);
  }, [node, projects]);

  const handleHealthCheck = useCallback(async () => {
    if (!node) return;

    try {
      await onHealthCheck(node.id);
      if (!isMountedRef.current) return;
      addToast(`Health check completed for ${node.name}`, "success");
    } catch (error) {
      if (!isMountedRef.current) return;
      const message = error instanceof Error ? error.message : "Health check failed";
      addToast(message, "error");
    }
  }, [addToast, node, onHealthCheck]);

  const handlePushSettings = useCallback(async () => {
    if (!node || !onPushSettings) return;
    setSyncError(null);
    setIsPushing(true);
    try {
      await onPushSettings(node.id);
      if (!isMountedRef.current) return;
      addToast("Settings pushed successfully", "success");
    } catch (error) {
      if (!isMountedRef.current) return;
      const message = error instanceof Error ? error.message : "Push settings failed";
      setSyncError(message);
      addToast(message, "error");
    } finally {
      if (isMountedRef.current) {
        setIsPushing(false);
      }
    }
  }, [addToast, node, onPushSettings]);

  const handlePullSettings = useCallback(async () => {
    if (!node || !onPullSettings) return;
    setSyncError(null);
    setIsPulling(true);
    try {
      await onPullSettings(node.id);
      if (!isMountedRef.current) return;
      addToast("Settings pulled successfully", "success");
    } catch (error) {
      if (!isMountedRef.current) return;
      const message = error instanceof Error ? error.message : "Pull settings failed";
      setSyncError(message);
      addToast(message, "error");
    } finally {
      if (isMountedRef.current) {
        setIsPulling(false);
      }
    }
  }, [addToast, node, onPullSettings]);

  const handleSyncAuth = useCallback(async () => {
    if (!node || !onSyncAuth) return;
    setSyncError(null);
    setIsSyncingAuth(true);
    try {
      await onSyncAuth(node.id);
      if (!isMountedRef.current) return;
      addToast("Auth credentials synced successfully", "success");
    } catch (error) {
      if (!isMountedRef.current) return;
      const message = error instanceof Error ? error.message : "Auth sync failed";
      setSyncError(message);
      addToast(message, "error");
    } finally {
      if (isMountedRef.current) {
        setIsSyncingAuth(false);
      }
    }
  }, [addToast, node, onSyncAuth]);

  const handleDismissSyncError = useCallback(() => {
    setSyncError(null);
  }, []);

  const handleDockerLifecycle = useCallback((action: "start" | "stop" | "restart" | "recreate" | "upgrade") => {
    if (action === "start") setDockerStatus("running");
    if (action === "stop") setDockerStatus("stopped");
    if (action === "restart") setDockerStatus("running");
    if (action === "recreate") setDockerStatus("recreating");
    if (action === "upgrade") setDockerStatus("recreating");
    addToast(`Docker action queued: ${action}`, "success");
  }, [addToast]);

  const handleSave = useCallback(async () => {
    if (!node || isSaving) return;

    const trimmedName = name.trim();
    if (!trimmedName) {
      addToast("Name is required", "error");
      return;
    }

    if (node.type === "remote" && !url.trim()) {
      addToast("URL is required for remote nodes", "error");
      return;
    }

    if (!Number.isFinite(maxConcurrent) || maxConcurrent < 1) {
      addToast("Concurrency must be at least 1", "error");
      return;
    }

    setIsSaving(true);
    try {
      await onUpdate(node.id, {
        name: trimmedName,
        url: node.type === "remote" ? url.trim() || undefined : undefined,
        apiKey: node.type === "remote" ? apiKey || undefined : undefined,
        maxConcurrent,
      });
      addToast(`Updated ${trimmedName}`, "success");
      setEditMode(false);
    } catch (error) {
      const message = error instanceof Error ? error.message : "Failed to update node";
      addToast(message, "error");
    } finally {
      setIsSaving(false);
    }
  }, [addToast, apiKey, isSaving, maxConcurrent, name, node, onUpdate, url]);

  const handleCancelEdit = useCallback(() => {
    if (!node) return;
    setName(node.name);
    setUrl(node.url ?? "");
    setApiKey(node.apiKey ?? "");
    setMaxConcurrent(node.maxConcurrent);
    setEditMode(false);
  }, [node]);

  if (!isOpen || !node) return null;

  return (
    <div className="modal-overlay open" onClick={onClose}>
      <div
        className="modal modal-lg node-detail-modal"
        onClick={(event) => event.stopPropagation()}
        role="dialog"
        aria-modal="true"
        aria-label={`Node details for ${node.name}`}
      >
        <div className="modal-header">
          <h3>Node Details</h3>
          <button className="modal-close" onClick={onClose} aria-label="Close node detail modal">&times;</button>
        </div>

        <div className="modal-body node-detail-modal__body">
          <section className="node-detail-modal__section">
            <div className="node-detail-modal__section-header">
              <h4>Overview</h4>
              {!editMode && (
                <button className="btn btn-sm" onClick={() => setEditMode(true)}>
                  <Pencil size={14} />
                  Edit
                </button>
              )}
            </div>

            <div className="node-detail-modal__grid">
              <label className="node-detail-modal__field">
                <span>Name</span>
                {editMode ? (
                  <input className="input" value={name} onChange={(event) => setName(event.target.value)} disabled={isSaving} />
                ) : (
                  <strong>{node.name}</strong>
                )}
              </label>

              <div className="node-detail-modal__field">
                <span>Type</span>
                <strong>{node.type === "local" ? "Local" : "Remote"}</strong>
              </div>

              <div className="node-detail-modal__field">
                <span>Status</span>
                <strong>{node.status}</strong>
              </div>

              <label className="node-detail-modal__field">
                <span>Max Concurrent</span>
                {editMode ? (
                  <input
                    className="input"
                    type="number"
                    min={1}
                    max={10}
                    value={maxConcurrent}
                    onChange={(event) => setMaxConcurrent(Number(event.target.value))}
                    disabled={isSaving}
                  />
                ) : (
                  <strong>{node.maxConcurrent}</strong>
                )}
              </label>

              {node.type === "remote" && (
                <>
                  <label className="node-detail-modal__field node-detail-modal__field--full">
                    <span>URL</span>
                    {editMode ? (
                      <input className="input" value={url} onChange={(event) => setUrl(event.target.value)} disabled={isSaving} />
                    ) : (
                      <strong>{node.url ?? "—"}</strong>
                    )}
                  </label>

                  <label className="node-detail-modal__field node-detail-modal__field--full">
                    <span>API Key</span>
                    {editMode ? (
                      <input
                        className="input"
                        type="password"
                        value={apiKey}
                        onChange={(event) => setApiKey(event.target.value)}
                        placeholder="Leave blank to keep unchanged"
                        disabled={isSaving}
                      />
                    ) : (
                      <strong>{node.apiKey ? "••••••••" : "Not configured"}</strong>
                    )}
                  </label>
                </>
              )}

              <div className="node-detail-modal__field">
                <span>Created</span>
                <strong>{formatTimestamp(node.createdAt)}</strong>
              </div>

              <div className="node-detail-modal__field">
                <span>Updated</span>
                <strong>{formatTimestamp(node.updatedAt)}</strong>
              </div>
            </div>

            {editMode && (
              <div className="node-detail-modal__edit-actions">
                <button className="btn btn-primary btn-sm" onClick={handleSave} disabled={isSaving}>
                  <Save size={14} />
                  {isSaving ? "Saving..." : "Save"}
                </button>
                <button className="btn btn-sm" onClick={handleCancelEdit} disabled={isSaving}>
                  <X size={14} />
                  Cancel
                </button>
              </div>
            )}
          </section>

          <section className="node-detail-modal__section">
            <h4>{node.type === "local" ? "Projects" : "Assigned Projects"} ({assignedProjects.length})</h4>
            {assignedProjects.length === 0 ? (
              <p className="node-detail-modal__empty">
                {node.type === "local"
                  ? "No projects are running on this node."
                  : "No projects are assigned to this node."}
              </p>
            ) : (
              <ul className="node-detail-modal__project-list">
                {assignedProjects.map((project) => (
                  <li key={project.id} className="node-detail-modal__project-item">
                    <span>{project.name}</span>
                    <code>{project.id}</code>
                  </li>
                ))}
              </ul>
            )}
          </section>

          <section className="node-detail-modal__section">
            <h4>Health</h4>
            <div className="node-detail-modal__health-row">
              <span>Status: <strong>{node.status}</strong></span>
              <span>Last check: <strong>{formatTimestamp(node.updatedAt)}</strong></span>
            </div>
          </section>

          <section className="node-detail-modal__section">
            <h4>Docker Management</h4>
            <div className="node-detail-modal__health-row">
              <span>Container: <strong>{dockerStatus}</strong></span>
              <span>Image: <strong>runfusion/fusion:latest</strong></span>
            </div>
            <div className="node-detail-modal__sync-actions">
              <button className="btn btn-sm" onClick={() => handleDockerLifecycle("start")}>Start</button>
              <button className="btn btn-sm" onClick={() => handleDockerLifecycle("stop")}>Stop</button>
              <button className="btn btn-sm" onClick={() => handleDockerLifecycle("restart")}>Restart</button>
              <button className="btn btn-sm" onClick={() => handleDockerLifecycle("recreate")}>Recreate</button>
              <button className="btn btn-sm" onClick={() => handleDockerLifecycle("upgrade")}>Upgrade Image</button>
            </div>
            <div className="node-detail-modal__docker-grid">
              <label className="node-detail-modal__field">
                <span>Environment Variables</span>
                <textarea className="input node-detail-modal__textarea" value={dockerEnv} onChange={(event) => setDockerEnv(event.target.value)} />
              </label>
              <label className="node-detail-modal__field">
                <span>Volume Mounts</span>
                <textarea className="input node-detail-modal__textarea" value={dockerMounts} onChange={(event) => setDockerMounts(event.target.value)} />
              </label>
            </div>
            <div className="node-detail-modal__sync-actions">
              <button className="btn btn-sm" onClick={() => addToast("Container logs opened", "success")}>View Logs</button>
              <button className="btn btn-sm" onClick={() => addToast("Config changes saved", "success")}>Save Config</button>
              <button className="btn btn-danger btn-sm" onClick={() => addToast("Delete flow opened (retain/remove volumes)", "warning")}>Delete Node…</button>
            </div>
          </section>

          {/* Settings Sync section — only for remote nodes */}
          {node.type === "remote" && (
            <section className="node-detail-modal__section">
              <h4>Settings Sync</h4>

              {syncStatus && (
                <div className="node-detail-modal__sync-status">
                  <span
                    className={`node-detail-modal__sync-dot ${getSyncStateDotClass(syncStatus.syncState)}`}
                    aria-hidden
                  />
                  <span>
                    Last sync:{" "}
                    <strong>
                      {syncStatus.lastSyncAt
                        ? formatRelativeTime(syncStatus.lastSyncAt)
                        : "Never synced"}
                    </strong>
                  </span>
                  {syncStatus.diffCount > 0 && (
                    <span className="node-detail-modal__sync-diff">
                      Differences: <strong>{syncStatus.diffCount}</strong>
                    </span>
                  )}
                </div>
              )}

              <div className="node-detail-modal__sync-actions">
                <button
                  className="btn btn-sm"
                  onClick={handlePushSettings}
                  disabled={isPushing || !onPushSettings}
                >
                  <Upload size={14} />
                  {isPushing ? "Pushing..." : "Push Settings"}
                </button>

                <button
                  className="btn btn-sm"
                  onClick={handlePullSettings}
                  disabled={isPulling || !onPullSettings}
                >
                  <Download size={14} />
                  {isPulling ? "Pulling..." : "Pull Settings"}
                </button>

                <button
                  className="btn btn-sm"
                  onClick={handleSyncAuth}
                  disabled={isSyncingAuth || !onSyncAuth}
                >
                  <Shield size={14} />
                  {isSyncingAuth ? "Syncing..." : "Sync Auth"}
                </button>
              </div>

              {syncError && (
                <div className="node-detail-modal__sync-error">
                  <span>{syncError}</span>
                  <button
                    className="node-detail-modal__sync-error-dismiss"
                    onClick={handleDismissSyncError}
                    aria-label="Dismiss error"
                  >
                    <X size={14} />
                  </button>
                </div>
              )}
            </section>
          )}

          {/* Sync History section — only for remote nodes */}
          {node.type === "remote" && (
            <section className="node-detail-modal__section">
              <h4>Sync History</h4>
              <SettingsSyncLog
                nodeId={node.id}
                entries={syncHistory}
                singleNode={true}
              />
            </section>
          )}
        </div>

        <div className="modal-actions node-detail-modal__actions">
          <button className="btn btn-sm" onClick={handleHealthCheck}>
            <Activity size={14} />
            Health Check
          </button>
          <button className="btn btn-sm" onClick={onClose}>Close</button>
        </div>
      </div>

      {/* Conflict resolution modal — rendered outside main modal container */}
      {node.type === "remote" && (
        <SettingsSyncConflictModal
          isOpen={showConflictModal}
          onClose={() => setShowConflictModal(false)}
          onResolve={onResolveConflicts ?? (async () => {})}
          conflicts={conflicts}
          localNodeName="Local"
          remoteNodeName={node.name}
          addToast={addToast}
        />
      )}
    </div>
  );
}