// "Resolve in VS Code" (OxygenHub's conflict resolver hands a conflict to
// the extension): vscode://oxygenhub.oxygen-vscode/resolve?url=…&bookmark=…&path=…
// Parsing and matching live here, apart from VS Code, so they are tested.

export interface ResolveRequest {
  /** The repository's clone URL on the hub. */
  url: string;
  bookmark: string;
  /** Relative to the repository root. */
  path: string;
}

/** Read a resolve request's query string, or say what is wrong with it. */
export function parseResolveQuery(query: string): ResolveRequest | string {
  const q = new URLSearchParams(query);
  const url = (q.get("url") ?? "").trim();
  const bookmark = (q.get("bookmark") ?? "").trim();
  const path = (q.get("path") ?? "").trim().replace(/^\/+/, "");
  if (!/^https?:\/\/[^\s]+$/.test(url)) {
    return "the link names no repository URL";
  }
  if (!bookmark || /[\s~^:?*[\\]/.test(bookmark) || bookmark.includes("..")) {
    return "the link names no valid bookmark";
  }
  if (!path || path.split("/").some((c) => c === "" || c === "." || c === ".." || c === ".oxy")) {
    return "the link names no valid path";
  }
  return { url, bookmark, path };
}

/** Whether two remote URLs name the same repository (case of the host and a trailing slash aside). */
export function sameRemote(a: string, b: string): boolean {
  const norm = (u: string) => {
    try {
      const x = new URL(u.trim());
      return `${x.protocol}//${x.host.toLowerCase()}${x.pathname.replace(/\/+$/, "").replace(/\.oxy$/, "")}`;
    } catch {
      return u.trim().replace(/\/+$/, "");
    }
  };
  return norm(a) === norm(b);
}

export interface PlanRequest {
  url: string;
  bookmark: string;
  /** `squash` (change into target) or `rebase` (change onto target). */
  kind: "squash" | "rebase";
  change: string;
  target: string;
}

/**
 * A rewrite planned on OxygenHub's swimlanes:
 * vscode://oxygenhub.oxygen-vscode/plan?url=…&bookmark=…&kind=…&change=…&target=…
 */
export function parsePlanQuery(query: string): PlanRequest | string {
  const q = new URLSearchParams(query);
  const base = parseResolveQuery(new URLSearchParams({ url: q.get("url") ?? "", bookmark: q.get("bookmark") ?? "", path: "x" }).toString());
  if (typeof base === "string") {
    return base;
  }
  const kind = q.get("kind");
  if (kind !== "squash" && kind !== "rebase") {
    return "the link names no squash or rebase";
  }
  const hex = /^[0-9a-f]{64}$/;
  const change = q.get("change") ?? "";
  const target = q.get("target") ?? "";
  if (!hex.test(change) || !hex.test(target) || change === target) {
    return "the link names no two changes";
  }
  return { url: base.url, bookmark: base.bookmark, kind, change, target };
}