// Who is in a forge team and what the team may do (issue 1563; novox/hq ADR 0466 §3, issue 971).
//
// The build keys sit on one forge user, nox-builder, in the team `builders`, which reads every repository and pushes
// nothing. The tools' account cannot read a team (the forge answers /orgs/novox/teams 403: it lacks read:organization),
// so the read goes with the site administrator's login, and only the read, as the branch protection read does (ADR 0375):
// GET /orgs/{org}/teams, GET /teams/{id}/members and, for a user's effective right on a repository, the repository as
// that user sees it (GiteaAdmin.repositoryPermission, which counts access through a team). Nothing is written.

/** A team as the forge's Team object answers it (GET /orgs/{org}/teams): the fields read here. */
export interface ForgeTeam {
  id: number;
  name: string;
  description?: string;
  /** The team's overall permission: none, read, write, admin, owner. */
  permission?: string;
  includes_all_repositories?: boolean;
  can_create_org_repo?: boolean;
  /** Per unit, the right the team has: units_map {"repo.code": "read", ...}. */
  units_map?: Record<string, string>;
  units?: string[];
}

/** What the module asks of the forge for this, with the site administrator's login (GiteaAdmin, client.ts). */
export interface TeamForge {
  teams(org: string): Promise<ForgeTeam[]>;
  teamMembers(teamId: number): Promise<string[]>;
  accountExists(user: string): Promise<boolean>;
  everyRepository(): Promise<{ full_name: string; owner: string; name: string }[]>;
  repositoryPermission(owner: string, repo: string, user: string): Promise<string>;
}

export interface TeamRights {
  team: string;
  id: number;
  description: string;
  members: string[];
  /** The team's overall permission. */
  permission: string;
  includes_all_repositories: boolean;
  can_create_org_repo: boolean;
  /** Per unit, read / write / admin / none. */
  units: Record<string, string>;
  /** True when no unit of the team is above read: the team pushes nothing, writes no issue, no pull request. */
  read_only: boolean;
}

const RANK: Record<string, number> = { none: 0, read: 1, write: 2, admin: 3, owner: 4 };

/** One team as a person reads it. A team the forge gives no units_map is read from its `permission`, which is what the
 *  older forge versions answer. */
export function teamRights(t: ForgeTeam, members: string[]): TeamRights {
  const units = t.units_map && Object.keys(t.units_map).length ? { ...t.units_map }
    : Object.fromEntries((t.units ?? []).map((u) => [u, t.permission ?? "none"]));
  const highest = Math.max(0, ...Object.values(units).map((r) => RANK[r] ?? 0));
  return {
    team: t.name, id: t.id, description: t.description ?? "", members: [...members].sort(), permission: t.permission ?? "none",
    includes_all_repositories: t.includes_all_repositories === true, can_create_org_repo: t.can_create_org_repo === true,
    units, read_only: highest <= RANK.read && (RANK[t.permission ?? "none"] ?? 0) <= RANK.read,
  };
}

export interface UserRights {
  user: string;
  /** The teams of the organisation the user is a member of. */
  teams: string[];
  /** How many repositories the forge gives the user each right on, effective (through a team or as a collaborator). */
  repositories: Record<string, number>;
  /** The repositories where the user may do more than read: empty for a read-only user. */
  writes: { repository: string; permission: string }[];
  /** Every repository and the right on it; only when asked. */
  every?: { repository: string; permission: string }[];
}

/** The teams of an organisation (or the one named), each with its members and rights; and for one user, the teams it is
 *  in and its effective right on every repository (or on those named), as the forge says it. Only reads. */
export async function readTeamRights(forge: TeamForge, org: string, opts: { team?: string; user?: string; repositories?: string[]; list?: boolean } = {}):
  Promise<{ organisation: string; teams: TeamRights[]; user?: UserRights }> {
  if (opts.user && !(await forge.accountExists(opts.user))) throw new Error(`no forge user ${opts.user}`);
  const all = await forge.teams(org);
  const named = opts.team ? all.filter((t) => t.name === opts.team) : all;
  if (opts.team && !named.length) throw new Error(`no team "${opts.team}" in ${org}: it holds ${all.map((t) => t.name).join(", ") || "none"}`);
  // Membership is read for every team when a user is asked, so the user's teams are all found.
  const wanted = opts.user ? all : named;
  const rights: TeamRights[] = [];
  for (const t of wanted) rights.push(teamRights(t, await forge.teamMembers(t.id)));
  const shown = opts.team ? rights.filter((r) => r.team === opts.team) : rights;
  const out: { organisation: string; teams: TeamRights[]; user?: UserRights } = { organisation: org, teams: shown };
  if (!opts.user) return out;
  const user = opts.user;
  const mine = rights.filter((r) => r.members.includes(user)).map((r) => r.team);
  const repos = (await forge.everyRepository()).filter((r) => !opts.repositories?.length || opts.repositories.includes(r.full_name));
  const counts: Record<string, number> = {};
  const writes: { repository: string; permission: string }[] = [];
  const every: { repository: string; permission: string }[] = [];
  for (const r of repos) {
    const permission = await forge.repositoryPermission(r.owner, r.name, user);
    counts[permission] = (counts[permission] ?? 0) + 1;
    if ((RANK[permission] ?? 0) > RANK.read) writes.push({ repository: r.full_name, permission });
    every.push({ repository: r.full_name, permission });
  }
  out.user = { user, teams: mine, repositories: counts, writes, ...(opts.list ? { every } : {}) };
  return out;
}