const CONFIGURATION_SCHEMA = "configuration-startup-closure.v1";

export const CONFIGURATION_ERRORS = Object.freeze({
  invalid_reference: "configuration_reference_invalid",
  empty_reference: "configuration_reference_empty",
  host_path: "configuration_host_path",
  outside_repo: "configuration_outside_repo",
  path_escape: "configuration_path_escape",
  missing: "configuration_resource_missing",
  ambiguous: "configuration_resource_ambiguous",
  unavailable: "configuration_resource_unavailable",
});

export const LIBRARY_ROOTS = Object.freeze([
  "linuxcnc/lib/hallib",
  "linuxcnc/lib",
]);

function asPathSet(paths) {
  if (paths instanceof Set) return paths;
  if (Array.isArray(paths)) return new Set(paths);
  if (paths && typeof paths === "object") return new Set(Object.keys(paths));
  return new Set();
}

function normalizePath(value) {
  if (typeof value !== "string" || value.length === 0) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, path: null };
  }
  if (value.includes("\0")) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, path: null };
  }
  const parts = [];
  for (const part of value.replaceAll("\\", "/").split("/")) {
    if (!part || part === ".") continue;
    if (part === "..") {
      if (parts.length === 0) return { status: "blocked", code: CONFIGURATION_ERRORS.path_escape, path: null };
      parts.pop();
      continue;
    }
    parts.push(part);
  }
  return { status: "accepted", code: null, path: parts.join("/") };
}

function dirname(path) {
  const index = path.lastIndexOf("/");
  return index < 0 ? "" : path.slice(0, index);
}

function joinPath(base, value) {
  return normalizePath(base ? `${base}/${value}` : value);
}

export function splitReference(rawValue) {
  if (typeof rawValue !== "string") {
    return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, value: null, args: [] };
  }
  const raw = rawValue.trim().replace(/^['"]|['"]$/g, "");
  if (!raw) return { status: "blocked", code: CONFIGURATION_ERRORS.empty_reference, value: null, args: [] };
  const tokens = raw.match(/(?:[^\s"']+|"[^"]*"|'[^']*')+/g) ?? [];
  if (tokens.length === 0) return { status: "blocked", code: CONFIGURATION_ERRORS.empty_reference, value: null, args: [] };
  const value = tokens[0].replace(/^['"]|['"]$/g, "");
  const args = tokens.slice(1).map((token) => token.replace(/^['"]|['"]$/g, ""));
  return { status: "accepted", code: null, raw, value, args };
}

export function resolveReference({ rawValue, entrypoint, availablePaths = [], libraryRoots = LIBRARY_ROOTS } = {}) {
  const parsed = splitReference(rawValue);
  if (parsed.status !== "accepted") return { ...parsed, path: null, attempted_paths: [] };
  if (typeof entrypoint !== "string" || entrypoint.length === 0) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, value: parsed.value, args: parsed.args, path: null, attempted_paths: [] };
  }
  if (parsed.value.startsWith("~") || parsed.value.startsWith("$") || parsed.value.startsWith("${")) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.host_path, value: parsed.value, args: parsed.args, path: null, attempted_paths: [] };
  }
  const available = asPathSet(availablePaths);
  const entry = normalizePath(entrypoint);
  if (entry.status !== "accepted") return { ...entry, value: parsed.value, args: parsed.args, attempted_paths: [] };
  let candidates;
  let resolution = "relative";
  if (parsed.value.startsWith("LIB:")) {
    resolution = "library";
    const libraryName = parsed.value.slice("LIB:".length);
    if (!libraryName || libraryName.startsWith("/") || libraryName.includes("..")) {
      return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, value: parsed.value, args: parsed.args, path: null, attempted_paths: [] };
    }
    candidates = libraryRoots.map((root) => normalizePath(`${root}/${libraryName}`)).filter((item) => item.status === "accepted").map((item) => item.path);
  } else if (parsed.value.startsWith("/")) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.outside_repo, value: parsed.value, args: parsed.args, path: null, attempted_paths: [] };
  } else if (parsed.value.startsWith("linuxcnc/")) {
    resolution = "repo_relative";
    const normalized = normalizePath(parsed.value);
    if (normalized.status !== "accepted") return { ...normalized, value: parsed.value, args: parsed.args, attempted_paths: [] };
    candidates = [normalized.path];
  } else {
    const normalized = joinPath(dirname(entry.path), parsed.value);
    if (normalized.status !== "accepted") return { ...normalized, value: parsed.value, args: parsed.args, attempted_paths: [] };
    if (normalized.path !== "linuxcnc" && !normalized.path.startsWith("linuxcnc/")) {
      return { status: "blocked", code: CONFIGURATION_ERRORS.outside_repo, value: parsed.value, args: parsed.args, path: null, attempted_paths: [normalized.path], resolution };
    }
    candidates = [normalized.path];
  }
  const existing = candidates.filter((candidate) => available.has(candidate));
  if (existing.length > 1) {
    return { status: "blocked", code: CONFIGURATION_ERRORS.ambiguous, value: parsed.value, args: parsed.args, path: null, attempted_paths: candidates, resolution };
  }
  if (existing.length === 1) {
    return { status: "resolved", code: null, value: parsed.value, args: parsed.args, path: existing[0], attempted_paths: candidates, resolution };
  }
  return { status: "blocked", code: CONFIGURATION_ERRORS.missing, value: parsed.value, args: parsed.args, path: null, attempted_paths: candidates, resolution };
}

export function resolveResourceRow(row, availablePaths, options = {}) {
  if (!row || typeof row !== "object") return { status: "blocked", code: CONFIGURATION_ERRORS.invalid_reference, path: null };
  const result = resolveReference({
    rawValue: row.raw_value ?? row.path,
    entrypoint: row.entrypoint,
    availablePaths,
    ...options,
  });
  return {
    resource_source_id: row.resource_source_id ?? null,
    entrypoint: row.entrypoint ?? null,
    original_path: row.path ?? null,
    original_status: row.parse_status ?? null,
    ...result,
  };
}

export function preflightConfiguration({ entrypoint, rows = [], availablePaths = [], libraryRoots = LIBRARY_ROOTS } = {}) {
  const resolved = rows.map((row) => resolveResourceRow(row, availablePaths, { libraryRoots }));
  const blocked = resolved.filter((row) => row.status !== "resolved");
  return {
    schema: CONFIGURATION_SCHEMA,
    entrypoint,
    status: blocked.length === 0 ? "ready" : "blocked",
    resource_count: resolved.length,
    resolved_count: resolved.length - blocked.length,
    blocked_count: blocked.length,
    resources: resolved,
  };
}

export { CONFIGURATION_SCHEMA };
export {
  CONFIGURATION_STARTUP_SCHEMA,
  STARTUP_SCHEMA,
  STARTUP_STATES,
  STARTUP_ERRORS,
  ConfigurationStartup,
  ConfigurationStartupStateMachine,
  startConfiguration,
  createConfigurationStartup,
} from "./configuration-startup.mjs";