import { useState, lazy, Suspense } from 'react';
import type { Contact, RadioConfig, MessagePath } from '../types';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription } from './ui/dialog';
import { Button } from './ui/button';
import {
  resolvePath,
  parsePathHops,
  calculateDistance,
  isValidLocation,
  formatDistance,
  type SenderInfo,
  type ResolvedPath,
  type PathHop,
} from '../utils/pathUtils';
import { formatTime } from '../utils/messageParser';
import { getMapFocusHash } from '../utils/urlHash';
import { useDistanceUnit } from '../contexts/DistanceUnitContext';
import type { DistanceUnit } from '../utils/distanceUnits';

const PathRouteMap = lazy(() =>
  import('./PathRouteMap').then((m) => ({ default: m.PathRouteMap }))
);

interface PathModalProps {
  open: boolean;
  onClose: () => void;
  paths: MessagePath[];
  senderInfo: SenderInfo;
  contacts: Contact[];
  config: RadioConfig | null;
  messageId?: number;
  packetId?: number | null;
  isOutgoingChan?: boolean;
  isResendable?: boolean;
  onResend?: (messageId: number, newTimestamp?: boolean) => void;
  onAnalyzePacket?: () => void;
}

export function PathModal({
  open,
  onClose,
  paths,
  senderInfo,
  contacts,
  config,
  messageId,
  packetId,
  isOutgoingChan,
  isResendable,
  onResend,
  onAnalyzePacket,
}: PathModalProps) {
  const { distanceUnit } = useDistanceUnit();
  const [mapModalIndex, setMapModalIndex] = useState<number | null>(null);
  const hasResendActions = isOutgoingChan && messageId !== undefined && onResend;
  const hasPaths = paths.length > 0;
  const showAnalyzePacket = hasPaths && packetId != null && onAnalyzePacket;

  // Resolve all paths
  const resolvedPaths = hasPaths
    ? paths.map((p) => ({
        ...p,
        resolved: resolvePath(p.path, senderInfo, contacts, config, p.path_len),
      }))
    : [];

  const hasSinglePath = paths.length === 1;

  return (
    <Dialog open={open} onOpenChange={(isOpen) => !isOpen && onClose()}>
      <DialogContent className="max-w-md max-h-[80dvh] flex flex-col">
        <DialogHeader>
          <DialogTitle>
            {hasPaths
              ? `Message Path${!hasSinglePath ? `s (${paths.length})` : ''}`
              : 'Message Status'}
          </DialogTitle>
          <DialogDescription>
            {!hasPaths ? (
              <>No echoes heard yet. Echoes appear when repeaters re-broadcast your message.</>
            ) : hasSinglePath ? (
              <>
                This shows <em>one route</em> that this message traveled through the mesh network.
                Repeater identities are inferred from locally known advert and path data, so some
                hops may be missing or misidentified when that data is incomplete.
              </>
            ) : (
              <>
                This message was received via <strong>{paths.length} different routes</strong>.
                Repeater identities are inferred from locally known advert and path data, so some
                hops may be missing or misidentified when that data is incomplete.
              </>
            )}
          </DialogDescription>
        </DialogHeader>

        {hasPaths && (
          <div className="flex-1 overflow-y-auto py-2 space-y-4">
            {showAnalyzePacket ? (
              <Button type="button" variant="outline" className="w-full" onClick={onAnalyzePacket}>
                Analyze Packet
              </Button>
            ) : null}

            {/* Raw path summary */}
            <div className="text-sm">
              {paths.map((p, index) => {
                const hops = parsePathHops(p.path, p.path_len);
                const rawPath = hops.length > 0 ? hops.join('->') : 'direct';
                return (
                  <div key={index}>
                    <span className="text-foreground/70 font-semibold">Path {index + 1}:</span>{' '}
                    <span className="font-mono text-muted-foreground">{rawPath}</span>
                  </div>
                );
              })}
            </div>

            {/* Straight-line distance (sender to receiver, same for all routes) */}
            {resolvedPaths.length > 0 &&
              isValidLocation(
                resolvedPaths[0].resolved.sender.lat,
                resolvedPaths[0].resolved.sender.lon
              ) &&
              isValidLocation(
                resolvedPaths[0].resolved.receiver.lat,
                resolvedPaths[0].resolved.receiver.lon
              ) && (
                <div className="text-sm pb-2 border-b border-border">
                  <span className="text-muted-foreground">Straight-line distance: </span>
                  <span className="font-medium">
                    {formatDistance(
                      calculateDistance(
                        resolvedPaths[0].resolved.sender.lat,
                        resolvedPaths[0].resolved.sender.lon,
                        resolvedPaths[0].resolved.receiver.lat,
                        resolvedPaths[0].resolved.receiver.lon
                      )!,
                      distanceUnit
                    )}
                  </span>
                </div>
              )}

            {resolvedPaths.map((pathData, index) => (
              <div key={index}>
                <div className="flex items-center justify-between mb-2 pb-1 border-b border-border">
                  {!hasSinglePath ? (
                    <div className="text-sm text-foreground/70 font-semibold">
                      Path {index + 1}{' '}
                      <span className="font-normal text-muted-foreground">
                        — received {formatTime(pathData.received_at)}
                      </span>
                    </div>
                  ) : (
                    <div />
                  )}
                  <button
                    onClick={() => setMapModalIndex(index)}
                    className="text-xs text-primary hover:underline cursor-pointer shrink-0 ml-2"
                  >
                    Map route
                  </button>
                </div>
                <PathVisualization
                  resolved={pathData.resolved}
                  senderInfo={senderInfo}
                  distanceUnit={distanceUnit}
                />
              </div>
            ))}

            {/* Map modal — opens when a "Map route" button is clicked */}
            <Dialog
              open={mapModalIndex !== null}
              onOpenChange={(open) => !open && setMapModalIndex(null)}
            >
              <DialogContent className="sm:max-w-2xl">
                <DialogHeader>
                  <DialogTitle>
                    {mapModalIndex !== null && !hasSinglePath
                      ? `Path ${mapModalIndex + 1} Route Map`
                      : 'Route Map'}
                  </DialogTitle>
                  <DialogDescription>
                    Map of known node locations along this message route.
                  </DialogDescription>
                </DialogHeader>
                {mapModalIndex !== null && (
                  <Suspense
                    fallback={
                      <div
                        className="rounded border border-border bg-muted/30 animate-pulse"
                        style={{ height: 400 }}
                      />
                    }
                  >
                    <PathRouteMap
                      resolved={resolvedPaths[mapModalIndex].resolved}
                      senderInfo={senderInfo}
                      height={400}
                    />
                  </Suspense>
                )}
              </DialogContent>
            </Dialog>
          </div>
        )}

        <div className="flex flex-col gap-2 pt-2">
          {hasResendActions && (
            <div className="flex gap-2">
              {isResendable && (
                <Button
                  variant="outline"
                  className="flex-1 min-w-0 h-auto py-2"
                  onClick={() => {
                    onResend(messageId);
                    onClose();
                  }}
                >
                  <span className="flex flex-col items-center leading-tight">
                    <span>↻ Resend</span>
                    <span className="text-[10px] font-normal opacity-80">
                      Only repeated by new repeaters
                    </span>
                  </span>
                </Button>
              )}
              <Button
                variant="destructive"
                className="flex-1 min-w-0 h-auto py-2"
                onClick={() => {
                  onResend(messageId, true);
                  onClose();
                }}
              >
                <span className="flex flex-col items-center leading-tight">
                  <span>↻ Resend as new</span>
                  <span className="text-[10px] font-normal opacity-80">
                    Will appear as duplicate to receivers
                  </span>
                </span>
              </Button>
            </div>
          )}
          <Button variant="secondary" className="h-auto py-2" onClick={onClose}>
            Close
          </Button>
        </div>
      </DialogContent>
    </Dialog>
  );
}

interface PathVisualizationProps {
  resolved: ResolvedPath;
  senderInfo: SenderInfo;
  distanceUnit: DistanceUnit;
}

function PathVisualization({ resolved, senderInfo, distanceUnit }: PathVisualizationProps) {
  // Track previous location for each hop to calculate distances
  // Returns null if previous hop was ambiguous or has invalid location
  const getPrevLocation = (hopIndex: number): { lat: number | null; lon: number | null } | null => {
    if (hopIndex === 0) {
      // Check if sender has valid location
      if (!isValidLocation(resolved.sender.lat, resolved.sender.lon)) {
        return null;
      }
      return { lat: resolved.sender.lat, lon: resolved.sender.lon };
    }
    const prevHop = resolved.hops[hopIndex - 1];
    // If previous hop was ambiguous, we can't show meaningful distances
    if (prevHop.matches.length > 1) {
      return null;
    }
    // If previous hop was unknown, we also can't calculate
    if (prevHop.matches.length === 0) {
      return null;
    }
    // Check if previous hop has valid location
    if (isValidLocation(prevHop.matches[0].lat, prevHop.matches[0].lon)) {
      return { lat: prevHop.matches[0].lat, lon: prevHop.matches[0].lon };
    }
    return null;
  };

  return (
    <div className="space-y-0">
      {/* Sender */}
      <PathNode
        label="Sender"
        name={resolved.sender.name}
        prefix={resolved.sender.prefix}
        distance={null}
        distanceUnit={distanceUnit}
        isFirst
        lat={resolved.sender.lat}
        lon={resolved.sender.lon}
        publicKey={senderInfo.publicKeyOrPrefix}
      />

      {/* Hops */}
      {resolved.hops.map((hop, index) => (
        <HopNode
          key={index}
          hop={hop}
          hopNumber={index + 1}
          prevLocation={getPrevLocation(index)}
          distanceUnit={distanceUnit}
        />
      ))}

      {/* Receiver */}
      <PathNode
        label="Receiver (me)"
        name={resolved.receiver.name}
        prefix={resolved.receiver.prefix}
        distance={calculateReceiverDistance(resolved)}
        distanceUnit={distanceUnit}
        isLast
        lat={resolved.receiver.lat}
        lon={resolved.receiver.lon}
        publicKey={resolved.receiver.publicKey ?? undefined}
      />

      {/* Total distance */}
      {resolved.totalDistances && resolved.totalDistances.length > 0 && (
        <div className="pt-3 mt-3 border-t border-border">
          <span className="text-sm text-muted-foreground">
            Presumed unambiguous distance covered:{' '}
          </span>
          <span className="text-sm font-medium">
            {resolved.hasGaps ? '>' : ''}
            {formatDistance(resolved.totalDistances[0], distanceUnit)}
          </span>
        </div>
      )}
    </div>
  );
}

interface PathNodeProps {
  label: string;
  name: string;
  prefix: string;
  distance: number | null;
  distanceUnit: DistanceUnit;
  isFirst?: boolean;
  isLast?: boolean;
  /** Optional coordinates for map link */
  lat?: number | null;
  lon?: number | null;
  /** Public key for map focus link (required if lat/lon provided) */
  publicKey?: string;
}

function PathNode({
  label,
  name,
  prefix,
  distance,
  distanceUnit,
  isFirst,
  isLast,
  lat,
  lon,
  publicKey,
}: PathNodeProps) {
  const hasLocation = isValidLocation(lat ?? null, lon ?? null) && publicKey;

  return (
    <div className="flex gap-3">
      {/* Vertical line and dot column */}
      <div className="flex flex-col items-center w-4 flex-shrink-0">
        {!isFirst && <div className="w-0.5 h-3 bg-border" />}
        <div className="w-3 h-3 rounded-full bg-primary flex-shrink-0" />
        {!isLast && <div className="w-0.5 flex-1 bg-border" />}
      </div>

      {/* Content */}
      <div className="pb-3 flex-1 min-w-0">
        <div className="text-sm font-semibold">
          <span className="text-primary">{label}:</span>{' '}
          <span className="text-primary font-mono">{prefix}</span>
        </div>
        <div className="font-medium truncate">
          {name}
          {distance !== null && (
            <span className="text-xs text-muted-foreground ml-1">
              - {formatDistance(distance, distanceUnit)}
            </span>
          )}
          {hasLocation && <CoordinateLink lat={lat!} lon={lon!} publicKey={publicKey!} />}
        </div>
      </div>
    </div>
  );
}

interface HopNodeProps {
  hop: PathHop;
  hopNumber: number;
  prevLocation: { lat: number | null; lon: number | null } | null;
  distanceUnit: DistanceUnit;
}

function HopNode({ hop, hopNumber, prevLocation, distanceUnit }: HopNodeProps) {
  const isAmbiguous = hop.matches.length > 1;
  const isUnknown = hop.matches.length === 0;

  // Calculate distance from previous location for a contact
  // Returns null if prev location unknown/ambiguous or contact has no valid location
  const getDistanceForContact = (contact: {
    lat: number | null;
    lon: number | null;
  }): number | null => {
    if (!prevLocation || prevLocation.lat === null || prevLocation.lon === null) {
      return null;
    }
    // Check if contact has valid location
    if (!isValidLocation(contact.lat, contact.lon)) {
      return null;
    }
    return calculateDistance(prevLocation.lat, prevLocation.lon, contact.lat, contact.lon);
  };

  return (
    <div className="flex gap-3">
      {/* Vertical line and dot column */}
      <div className="flex flex-col items-center w-4 flex-shrink-0">
        <div className="w-0.5 h-3 bg-border" />
        <div className="w-3 h-3 rounded-full bg-primary/50 flex-shrink-0" />
        <div className="w-0.5 flex-1 bg-border" />
      </div>

      {/* Content */}
      <div className="pb-3 flex-1 min-w-0">
        <div className="text-sm font-semibold">
          <span className="text-foreground/80">Hop {hopNumber}:</span>{' '}
          <span className="text-primary font-mono">{hop.prefix}</span>
          {isAmbiguous && <span className="text-warning ml-1 font-normal">(ambiguous)</span>}
        </div>

        {isUnknown ? (
          <div className="font-medium text-muted-foreground">&lt;UNKNOWN&gt;</div>
        ) : isAmbiguous ? (
          <div>
            {hop.matches.map((contact) => {
              const dist = getDistanceForContact(contact);
              const hasLocation = isValidLocation(contact.lat, contact.lon);
              return (
                <div key={contact.public_key} className="font-medium truncate">
                  {contact.name || contact.public_key.slice(0, 12)}
                  {dist !== null && (
                    <span className="text-xs text-muted-foreground ml-1">
                      - {formatDistance(dist, distanceUnit)}
                    </span>
                  )}
                  {hasLocation && (
                    <CoordinateLink
                      lat={contact.lat!}
                      lon={contact.lon!}
                      publicKey={contact.public_key}
                    />
                  )}
                </div>
              );
            })}
          </div>
        ) : (
          <div className="font-medium truncate">
            {hop.matches[0].name || hop.matches[0].public_key.slice(0, 12)}
            {hop.distanceFromPrev !== null && (
              <span className="text-xs text-muted-foreground ml-1">
                - {formatDistance(hop.distanceFromPrev, distanceUnit)}
              </span>
            )}
            {isValidLocation(hop.matches[0].lat, hop.matches[0].lon) && (
              <CoordinateLink
                lat={hop.matches[0].lat!}
                lon={hop.matches[0].lon!}
                publicKey={hop.matches[0].public_key}
              />
            )}
          </div>
        )}
      </div>
    </div>
  );
}

/**
 * Render clickable coordinates that open the map focused on the contact
 */
function CoordinateLink({ lat, lon, publicKey }: { lat: number; lon: number; publicKey: string }) {
  const handleClick = (e: React.MouseEvent) => {
    e.preventDefault();
    e.stopPropagation();
    // Open map in new tab with focus on this contact
    const url = window.location.origin + window.location.pathname + getMapFocusHash(publicKey);
    window.open(url, '_blank');
  };

  return (
    <span
      className="text-xs text-muted-foreground font-mono cursor-pointer hover:text-primary hover:underline ml-1"
      role="button"
      tabIndex={0}
      onKeyDown={(e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          e.preventDefault();
          (e.currentTarget as HTMLElement).click();
        }
      }}
      onClick={handleClick}
      title="View on map"
    >
      ({lat.toFixed(4)}, {lon.toFixed(4)})
    </span>
  );
}

function calculateReceiverDistance(resolved: ResolvedPath): number | null {
  // Get last hop's location (if any)
  let prevLat: number | null = null;
  let prevLon: number | null = null;

  if (resolved.hops.length > 0) {
    const lastHop = resolved.hops[resolved.hops.length - 1];
    // Only use last hop if it's unambiguous and has valid location
    if (
      lastHop.matches.length === 1 &&
      isValidLocation(lastHop.matches[0].lat, lastHop.matches[0].lon)
    ) {
      prevLat = lastHop.matches[0].lat;
      prevLon = lastHop.matches[0].lon;
    }
  } else {
    // No hops, calculate from sender to receiver (if sender has valid location)
    if (isValidLocation(resolved.sender.lat, resolved.sender.lon)) {
      prevLat = resolved.sender.lat;
      prevLon = resolved.sender.lon;
    }
  }

  if (prevLat === null || prevLon === null) {
    return null;
  }

  // Check receiver has valid location
  if (!isValidLocation(resolved.receiver.lat, resolved.receiver.lon)) {
    return null;
  }

  return calculateDistance(prevLat, prevLon, resolved.receiver.lat, resolved.receiver.lon);
}