import type {
  GateIssue,
  MediaAsset,
  MediaEditPlan,
  MediaRender,
  MediaRenderStatus,
  PlatformProfileSummary,
} from "@rakazo/contracts";

/*
 * Pure view logic for the mobile media screens: which plan and render make a
 * variant, when to poll, what can be approved or shared, and where a media
 * push notification leads. Screens stay thin; this stays testable.
 */

/** Clients poll while work runs; there is no realtime media subscription. */
export const MEDIA_POLL_MS = 2_000;

const ACTIVE_RENDER: ReadonlySet<MediaRenderStatus> = new Set(["queued", "rendering", "gating"]);

export function isRenderActive(render: Pick<MediaRender, "status"> | null | undefined): boolean {
  return Boolean(render && ACTIVE_RENDER.has(render.status));
}

export type MediaVariant = {
  profileId: string;
  profileName: string;
  plan: MediaEditPlan;
  /** Newest render of the newest plan version, any quality. */
  latest: MediaRender | null;
  /** Newest final render of the newest plan version. */
  final: MediaRender | null;
  /** Newest render with a playable video: final when done, else the draft. */
  preview: MediaRender | null;
};

function newer<T extends { createdAt: string; id: string }>(a: T, b: T): boolean {
  return a.createdAt === b.createdAt ? a.id > b.id : a.createdAt > b.createdAt;
}

function newest<T extends { createdAt: string; id: string }>(items: T[]): T | null {
  let best: T | null = null;
  for (const item of items) if (!best || newer(item, best)) best = item;
  return best;
}

export function videoOutput(render: Pick<MediaRender, "outputs"> | null) {
  return render?.outputs.find((output) => output.kind === "video") ?? null;
}

/** One variant per profile: its newest plan version and that plan's renders. */
export function projectVariants(input: {
  profileIds: string[];
  plans: MediaEditPlan[];
  renders: MediaRender[];
  profiles: Pick<PlatformProfileSummary, "id" | "name">[];
}): MediaVariant[] {
  const names = new Map(input.profiles.map((profile) => [profile.id, profile.name]));
  const variants: MediaVariant[] = [];
  for (const profileId of input.profileIds) {
    const plans = input.plans.filter((plan) => plan.profileId === profileId);
    let plan: MediaEditPlan | null = null;
    for (const candidate of plans) {
      if (
        !plan ||
        candidate.version > plan.version ||
        (candidate.version === plan.version && newer(candidate, plan))
      ) {
        plan = candidate;
      }
    }
    if (!plan) continue;
    const planId = plan.id;
    const renders = input.renders.filter((render) => render.planId === planId);
    const final = newest(renders.filter((render) => render.quality === "final"));
    const playable = renders.filter((render) => render.status === "done" && videoOutput(render));
    const finalDone = playable.filter((render) => render.quality === "final");
    variants.push({
      profileId,
      profileName: names.get(profileId) ?? profileId,
      plan,
      latest: newest(renders),
      final,
      preview: newest(finalDone) ?? newest(playable),
    });
  }
  return variants;
}

export type VariantState =
  | "planned"
  | "rendering"
  | "draft_ready"
  | "approved_rendering"
  | "ready"
  | "blocked"
  | "failed";

export function variantState(variant: MediaVariant): VariantState {
  const latest = variant.latest;
  if (!latest) return "planned";
  if (isRenderActive(latest))
    return latest.quality === "final" ? "approved_rendering" : "rendering";
  if (latest.status === "blocked") return "blocked";
  if (latest.status === "failed" || latest.status === "canceled") return "failed";
  return latest.quality === "final" ? "ready" : "draft_ready";
}

/** Approval starts the final render; it needs a plan and no render in flight. */
export function canApprove(variant: MediaVariant): boolean {
  const state = variantState(variant);
  return state === "draft_ready" || state === "planned" || state === "failed";
}

/** Only a final render that passed its gate leaves the app. */
export function canShare(variant: MediaVariant): boolean {
  return Boolean(variant.final && variant.final.status === "done" && videoOutput(variant.final));
}

export function blockers(render: Pick<MediaRender, "gateReport"> | null): GateIssue[] {
  return render?.gateReport?.issues.filter((issue) => issue.severity === "block") ?? [];
}

export function shouldPollProject(renders: MediaRender[]): boolean {
  return renders.some(isRenderActive);
}

/** Device items that still have to upload before the server can work on them. */
export function needsUpload(asset: Pick<MediaAsset, "storage" | "ingestState">): boolean {
  return asset.storage === "remote" || asset.ingestState === "awaiting_upload";
}

export type ProjectReadiness = "uploading" | "processing" | "ready" | "failed";

/** Items this device has to upload: only its own library can send them. */
export function uploadsFromDevice<
  T extends Pick<MediaAsset, "storage" | "ingestState" | "sourceId">,
>(assets: T[], deviceSourceId: string | null): T[] {
  return deviceSourceId
    ? assets.filter((asset) => asset.sourceId === deviceSourceId && needsUpload(asset))
    : [];
}

/**
 * Whether a project's material is ready for automatic plans: every item
 * uploaded and analyzed (or at least proxied when analysis is unavailable).
 * "uploading" means this device still holds originals; items waiting for
 * another device count as processing.
 */
export function projectReadiness(
  assets: Pick<MediaAsset, "storage" | "ingestState" | "sourceId">[],
  analysisAvailable: boolean,
  deviceSourceId: string | null,
): ProjectReadiness {
  if (assets.length === 0) return "processing";
  if (uploadsFromDevice(assets, deviceSourceId).length > 0) return "uploading";
  if (assets.some(needsUpload)) return "processing";
  const usable = assets.filter((asset) => asset.ingestState !== "failed");
  if (usable.length === 0) return "failed";
  const done = analysisAvailable ? ["analyzed"] : ["proxied", "analyzed"];
  return usable.every((asset) => done.includes(asset.ingestState)) ? "ready" : "processing";
}

/** File name for a render shared from the device. */
export function shareFileName(renderId: string, fileName: string): string {
  const extension = /\.[A-Za-z0-9]{1,5}$/.exec(fileName)?.[0] ?? ".mp4";
  return `render-${renderId.replace(/[^A-Za-z0-9_-]/g, "").slice(0, 64)}${extension.toLowerCase()}`;
}

export function renderFileUrl(
  apiBase: string,
  renderId: string,
  fileName: string,
  download = false,
): string {
  const base = apiBase.replace(/\/+$/, "");
  const path = `/api/media/renders/${encodeURIComponent(renderId)}/files/${encodeURIComponent(fileName)}`;
  return `${base}${path}${download ? "?download=1" : ""}`;
}

export function assetThumbUrl(apiBase: string, assetId: string): string {
  return `${apiBase.replace(/\/+$/, "")}/api/media/assets/${encodeURIComponent(assetId)}/thumb`;
}

/** Push payload the server sends when a render finishes or is blocked. */
export type MediaRenderPushData = {
  kind: "media.render";
  renderId: string;
  projectId: string;
  status: MediaRenderStatus;
};

/** Route a tapped notification to its project, or null for any other push. */
export function mediaNotificationRoute(
  data: unknown,
): { pathname: "/media-project"; params: { projectId: string } } | null {
  if (!data || typeof data !== "object") return null;
  const record = data as Record<string, unknown>;
  if (record.kind !== "media.render") return null;
  const projectId = record.projectId;
  if (typeof projectId !== "string" || !/^[A-Za-z0-9_-]{1,64}$/.test(projectId)) return null;
  return { pathname: "/media-project", params: { projectId } };
}

export type LibraryAccess = "undetermined" | "denied" | "blocked" | "limited" | "all";

/** Collapse a media library permission response into what the screen needs. */
export function libraryAccess(permission: {
  granted: boolean;
  canAskAgain: boolean;
  status: string;
  accessPrivileges?: "all" | "limited" | "none";
}): LibraryAccess {
  if (permission.granted) return permission.accessPrivileges === "limited" ? "limited" : "all";
  if (permission.status === "undetermined") return "undetermined";
  return permission.canAskAgain ? "denied" : "blocked";
}

export function formatDuration(ms: number): string {
  const total = Math.max(0, Math.round(ms / 1000));
  const hours = Math.floor(total / 3600);
  const minutes = Math.floor((total % 3600) / 60);
  const seconds = String(total % 60).padStart(2, "0");
  return hours > 0
    ? `${hours}:${String(minutes).padStart(2, "0")}:${seconds}`
    : `${minutes}:${seconds}`;
}