/**
 * Bundle generation — display-chain routing.
 *
 * kiosk.display_id → layouts for display → cells → cameras
 * No label filtering for v0.1.
 */
import { createHash } from "node:crypto";
import type { Observable } from "@bsb/base";
import type { Repository } from "./db/repository.js";
import type { SecretsApi } from "./secrets.js";
import type { Camera, CameraStream } from "./types.js";

/**
 * Build a playable RTSP URL from stream component columns + camera credentials.
 * If the stream has rtsp_host/rtsp_path set (ONVIF-discovered), constructs the
 * URL from components with properly URL-encoded username and password from the
 * camera row. Otherwise falls back to the stream's rtsp_uri as-is (backward
 * compat for RTSP-type cameras and legacy data).
 */
function buildStreamRtspUri(stream: CameraStream, cam: Camera): string {
  // Only build from components if both host and path are present
  if (stream.rtsp_host && stream.rtsp_path != null) {
    const host = stream.rtsp_host;
    const port = stream.rtsp_port ?? 554;
    const path = stream.rtsp_path.startsWith("/") ? stream.rtsp_path : `/${stream.rtsp_path}`;

    // Inject credentials from the camera row
    let userinfo = "";
    if (cam.onvif_username) {
      const user = encodeURIComponent(cam.onvif_username);
      const pass = cam.onvif_password ? encodeURIComponent(cam.onvif_password) : "";
      userinfo = pass ? `${user}:${pass}@` : `${user}@`;
    }

    const portSuffix = port === 554 ? "" : `:${String(port)}`;
    return `rtsp://${userinfo}${host}${portSuffix}${path}`;
  }
  // Backward compat: use the stored rtsp_uri as-is
  return stream.rtsp_uri;
}

export interface BundleCamera {
  id: number;
  name: string;
  type: string;
  rtsp_url: string | null;
  onvif_host: string | null;
  onvif_port: number | null;
  onvif_username: string | null;
  onvif_password_encrypted: string | null;
  event_source: string;
  event_sink: string;
  stream_policy: string;
  streams: Array<{
    id: number;
    role: string;
    name: string;
    /** Final playable RTSP URL with properly encoded credentials. */
    rtsp_uri: string;
    width: number | null;
    height: number | null;
    encoding: string | null;
    framerate: number | null;
  }>;
}

export interface BundleCell {
  row: number;
  col: number;
  row_span: number;
  col_span: number;
  content_type: string;
  camera_id: number | null;
  stream_selector: string | null;
  web_url: string | null;
  html_content: string | null;
  cooling_timeout_seconds: number | null;
  fit: "cover" | "contain" | "fill";
  /** Smart URL action steps — automated login/navigation sequence. */
  smart_url?: {
    steps: Array<{
      type: string;
      url?: string;
      selector?: string;
      value?: string;
      value_encrypted?: string;
      delay_ms?: number;
      timeout_ms?: number;
      script?: string;
    }>;
    login_detect_url?: string;
    session_check_interval_ms?: number;
  };
}

export interface BundleLayout {
  id: number;
  name: string;
  /** Computed from cells: max(col + col_span). 1 if no cells. */
  grid_cols: number;
  /** Computed from cells: max(row + row_span). 1 if no cells. */
  grid_rows: number;
  priority: string;
  cooling_timeout_seconds: number | null;
  preload_camera_ids: number[];
  resets_idle_timer: boolean;
  /** True if the kiosk's display has this layout as its default_layout_id. */
  is_default: boolean;
  cells: BundleCell[];
}

export interface BundleDisplay {
  id: number;
  name: string;
  width_px: number;
  height_px: number;
  idle_timeout_seconds: number;
  sleep_timeout_seconds: number;
  default_layout_id: number | null;
}

export interface BundleDisplayWithLayouts extends BundleDisplay {
  layouts: BundleLayout[];
}

export interface BundleGpioBinding {
  id: number;
  chip: string;
  pin: number;
  direction: "in" | "out";
  pull: "up" | "down" | "none" | null;
  edge: "rising" | "falling" | "both" | null;
  topic: string;
}

export interface KioskBundle {
  kiosk_id: number;
  kiosk_name: string;
  /**
   * @deprecated Use `displays` (array). Kept for backward compat with older
   * kiosk builds that consume a single display. Mirrors `displays[0]`.
   */
  display: BundleDisplay;
  /**
   * @deprecated Use `displays[N].layouts`. Mirrors `displays[0].layouts` for
   * older kiosk builds.
   */
  layouts: BundleLayout[];
  /** All physical displays driven by this kiosk. New (multi-display) shape. */
  displays: BundleDisplayWithLayouts[];
  cameras: BundleCamera[];
  gpio_bindings: BundleGpioBinding[];
  version: string;
}

export async function generateBundle(
  repo: Repository,
  secrets: SecretsApi,
  kioskId: number,
  clusterKey: string | undefined,
  obs?: Observable,
): Promise<KioskBundle | null> {
  const span = obs?.startSpan("generateBundle", { "kiosk.id": kioskId });
  const kiosk = await repo.getKioskById(kioskId);
  if (!kiosk) {
    span?.log.info("bundle: kiosk {id} not found", { id: String(kioskId) });
    span?.end();
    return null;
  }

  // Per-kiosk encryption key (preferred) — decrypt from server storage.
  let kioskEncryptKey: string | undefined;
  if (kiosk.encrypt_key_encrypted) {
    try {
      kioskEncryptKey = secrets.decryptString(kiosk.encrypt_key_encrypted, "kiosk-encrypt");
    } catch {
      // Decrypt failed — fall back to cluster key.
    }
  }

  // Find all displays for this kiosk (displays now point to kiosks via kiosk_id)
  const kioskDisplays = await repo.listDisplaysForKiosk(kioskId);
  // Fall back to legacy kiosk.display_id if no displays point to this kiosk yet
  const allDisplays = kioskDisplays.length > 0
    ? kioskDisplays
    : (kiosk.display_id ? [await repo.getDisplayById(kiosk.display_id)].filter((d): d is NonNullable<typeof d> => d != null) : []);

  // Admin can disable a display — kiosk must never open a window on it.
  const displays = allDisplays.filter((d) => d.is_enabled);
  if (displays.length === 0) {
    span?.log.info("bundle: kiosk {id} has no enabled displays", { id: String(kioskId) });
    span?.end();
    return null;
  }

  // Collect camera IDs across ALL displays' layouts (de-duped).
  const allLayoutIds = new Set<number>();
  for (const d of displays) {
    for (const l of await repo.layoutsForDisplayId(d.id)) allLayoutIds.add(l.id);
  }
  const cameras = await repo.camerasForLayoutIds([...allLayoutIds]);

  async function buildLayouts(displayId: number, defaultLayoutId: number | null): Promise<BundleLayout[]> {
    const layouts = await repo.layoutsForDisplayId(displayId);
    const result: BundleLayout[] = [];
    for (const l of layouts) {
      const cells = await repo.layoutCells(l.id);
      let gridCols = 1;
      let gridRows = 1;
      for (const c of cells) {
        const right = c.col + c.col_span;
        const bottom = c.row + c.row_span;
        if (right > gridCols) gridCols = right;
        if (bottom > gridRows) gridRows = bottom;
      }
      const bundleCells: BundleCell[] = [];
      for (const c of cells) {
        // If the cell has an entity, prefer its current content so admin
        // edits to the entity propagate without forcing a cell-touch. The
        // bundle still ships the legacy camera_id/web_url/html_content shape
        // so the existing Rust kiosk consumes it unchanged.
        let contentType = c.content_type;
        let cameraId = c.camera_id;
        let webUrl = c.web_url;
        let htmlContent = c.html_content;
        if (c.entity_id != null) {
          const ent = await repo.getEntityById(c.entity_id);
          if (ent) {
            // Dashboard entities are surfaced to the kiosk as `web` cells
            // pointing at /dash/<dashboard_id> — kiosk WebKit handles them
            // identically to user-supplied web cells.
            contentType = ent.type === "dashboard" ? "web" : ent.type;
            cameraId = ent.type === "camera" ? ent.camera_id : null;
            webUrl =
              ent.type === "web" ? ent.web_url :
              ent.type === "dashboard" && ent.dashboard_id ? `/dash/${ent.dashboard_id}` :
              null;
            htmlContent = ent.type === "html" ? ent.html_content : null;
          }
        }
        bundleCells.push({
          row: c.row,
          col: c.col,
          row_span: c.row_span,
          col_span: c.col_span,
          content_type: contentType,
          camera_id: cameraId,
          stream_selector: c.stream_selector,
          web_url: webUrl,
          html_content: htmlContent,
          cooling_timeout_seconds: c.cooling_timeout_seconds,
          fit: c.fit,
          // Smart URL: encrypted credentials use per-kiosk key so each
          // kiosk's bundle has uniquely encrypted values.
          smart_url: c.options?.["smart_url"] ? (() => {
            const raw = c.options["smart_url"] as any;
            const steps = Array.isArray(raw.steps) ? raw.steps.map((s: any) => {
              const step = { ...s };
              // Encrypt plaintext values with per-kiosk key for transport.
              const ek = kioskEncryptKey ?? clusterKey;
              if (step.value && step.type === "fill" && ek) {
                step.value_encrypted = secrets.encryptForCluster(step.value, ek);
                delete step.value;
              }
              return step;
            }) : [];
            return {
              steps,
              login_detect_url: raw.login_detect_url,
              session_check_interval_ms: raw.session_check_interval_ms,
            };
          })() : undefined,
        });
      }
      result.push({
        id: l.id,
        name: l.name,
        grid_cols: gridCols,
        grid_rows: gridRows,
        priority: l.priority,
        cooling_timeout_seconds: l.cooling_timeout_seconds,
        preload_camera_ids: l.preload_camera_ids,
        resets_idle_timer: l.resets_idle_timer,
        is_default: defaultLayoutId === l.id,
        cells: bundleCells,
      });
    }
    return result;
  }

  const bundleDisplays: BundleDisplayWithLayouts[] = [];
  for (const display of displays) {
    bundleDisplays.push({
      id: display.id,
      name: display.name,
      width_px: display.width_px,
      height_px: display.height_px,
      idle_timeout_seconds: display.idle_timeout_seconds,
      sleep_timeout_seconds: display.sleep_timeout_seconds,
      default_layout_id: display.default_layout_id,
      layouts: await buildLayouts(display.id, display.default_layout_id),
    });
  }

  const bundleCameras: BundleCamera[] = [];
  for (const cam of cameras) {
    const streams = await repo.listCameraStreams(cam.id);
    const effectiveStreams = streams.length > 0 ? streams : (
      cam.type === "rtsp" && cam.rtsp_url
        ? [{
          id: 0,
          role: "main" as const,
          name: "Main",
          rtsp_uri: cam.rtsp_url,
          width: null,
          height: null,
          encoding: null,
          framerate: null,
        }]
        : []
    );
    // Encrypt camera password with per-kiosk key if available (stronger
    // isolation — compromised SD only exposes this kiosk's cameras). Falls
    // back to shared cluster_key for kiosks that paired before per-kiosk
    // keys were introduced.
    let onvifPwEncrypted: string | null = null;
    const encryptKey = kioskEncryptKey ?? clusterKey;
    if (cam.onvif_password && encryptKey) {
      onvifPwEncrypted = secrets.encryptForCluster(cam.onvif_password, encryptKey);
    }
    bundleCameras.push({
      id: cam.id,
      name: cam.name,
      type: cam.type,
      rtsp_url: cam.rtsp_url,
      onvif_host: cam.onvif_host,
      onvif_port: cam.onvif_port,
      onvif_username: cam.onvif_username,
      onvif_password_encrypted: onvifPwEncrypted,
      event_source: cam.event_source,
      event_sink: cam.event_sink,
      stream_policy: cam.stream_policy,
      streams: effectiveStreams.map((s) => ({
        id: s.id,
        role: s.role,
        name: s.name,
        // Build final playable URL from components + camera credentials
        // when available; falls back to stored rtsp_uri for backward compat.
        rtsp_uri: "rtsp_host" in s ? buildStreamRtspUri(s as CameraStream, cam) : s.rtsp_uri,
        width: s.width,
        height: s.height,
        encoding: s.encoding,
        framerate: s.framerate,
      })),
    });
  }

  const gpioBindings: BundleGpioBinding[] = (await repo.listGpioBindings(kioskId)).map((g) => ({
    id: g.id,
    chip: g.chip,
    pin: g.pin,
    direction: g.direction,
    pull: g.pull,
    edge: g.edge,
    topic: g.topic,
  }));

  // Mirror first display into the legacy top-level `display` + `layouts` so
  // older kiosk builds keep working unchanged. New builds should read
  // `displays`.
  const primary = bundleDisplays[0]!;
  const bundle: KioskBundle = {
    kiosk_id: kioskId,
    kiosk_name: kiosk.name,
    display: {
      id: primary.id,
      name: primary.name,
      width_px: primary.width_px,
      height_px: primary.height_px,
      idle_timeout_seconds: primary.idle_timeout_seconds,
      sleep_timeout_seconds: primary.sleep_timeout_seconds,
      default_layout_id: primary.default_layout_id,
    },
    layouts: primary.layouts,
    displays: bundleDisplays,
    cameras: bundleCameras,
    gpio_bindings: gpioBindings,
    version: "",
  };

  bundle.version = createHash("sha256")
    .update(JSON.stringify(bundle))
    .digest("hex");

  span?.log.info("bundle generated for kiosk {id} version {ver}", {
    id: String(kioskId),
    ver: bundle.version.slice(0, 12),
  });
  span?.end();
  return bundle;
}