// Copyright 2018-2025 the Deno authors. MIT license.
import * as dntShim from "../../../../../_dnt.shims.js";
import { dirname } from "../../path/1.1.4/dirname.js";
import { resolve } from "../../path/1.1.4/resolve.js";
import { ensureDir, ensureDirSync } from "./ensure_dir.js";
import { getFileInfoType } from "./_get_file_info_type.js";
import { toPathString } from "./_to_path_string.js";
import { isWindows } from "../../internal/1.0.12/os.js";
function resolveSymlinkTarget(target, linkName) {
    if (typeof target !== "string")
        return target; // URL is always absolute path
    if (typeof linkName === "string") {
        return resolve(dirname(linkName), target);
    }
    else {
        return new URL(target, linkName);
    }
}
function getSymlinkOption(type) {
    return isWindows ? { type: type === "dir" ? "dir" : "file" } : undefined;
}
/**
 * Asynchronously ensures that the link exists, and points to a valid file.
 *
 * If the parent directories for the link do not exist, they are created. If the
 * link already exists, and it is not modified, this function does nothing. If
 * the link already exists, and it does not point to the given target, an error
 * is thrown.
 *
 * Requires `--allow-read` and `--allow-write` permissions.
 *
 * @see {@link https://docs.deno.com/runtime/manual/basics/permissions#file-system-access}
 * for more information on Deno's permissions system.
 *
 * @param target The source file path as a string or URL. If it is a relative path string, it have to be relative to the link path.
 * @param linkName The destination link path as a string or URL.
 *
 * @returns A void promise that resolves once the link exists.
 *
 * @example Basic usage
 * ```ts ignore
 * import { ensureSymlink } from "@std/fs/ensure-symlink";
 *
 * // Ensures the link `./targetFile.link.dat` exists and points to `./targetFile.dat`
 * await ensureSymlink("./targetFile.dat", "./targetFile.link.dat");
 * ```
 *
 * @example Ensuring a link in a folder
 * ```ts ignore
 * import { ensureSymlink } from "@std/fs/ensure-symlink";
 *
 * // Ensures the link `./folder/targetFile.link.dat` exists and points to `./folder/targetFile.dat`
 * await ensureSymlink("./targetFile.dat", "./folder/targetFile.link.dat");
 * ```
 */
export async function ensureSymlink(target, linkName) {
    const targetRealPath = resolveSymlinkTarget(target, linkName);
    let srcStatInfo;
    try {
        srcStatInfo = await dntShim.Deno.lstat(targetRealPath);
    }
    catch (error) {
        if (error instanceof dntShim.Deno.errors.NotFound) {
            throw new dntShim.Deno.errors.NotFound(`Cannot ensure symlink as the target path does not exist: ${targetRealPath}`);
        }
        throw error;
    }
    const srcFilePathType = getFileInfoType(srcStatInfo);
    await ensureDir(dirname(toPathString(linkName)));
    const options = getSymlinkOption(srcFilePathType);
    try {
        await dntShim.Deno.symlink(target, linkName, options);
    }
    catch (error) {
        if (!(error instanceof dntShim.Deno.errors.AlreadyExists)) {
            throw error;
        }
        const linkStatInfo = await dntShim.Deno.lstat(linkName);
        if (!linkStatInfo.isSymlink) {
            const type = getFileInfoType(linkStatInfo);
            throw new dntShim.Deno.errors.AlreadyExists(`A '${type}' already exists at the path: ${linkName}`);
        }
        const linkPath = await dntShim.Deno.readLink(linkName);
        const linkRealPath = resolve(linkPath);
        if (linkRealPath !== targetRealPath) {
            throw new dntShim.Deno.errors.AlreadyExists(`A symlink targeting to an undesired path already exists: ${linkName} -> ${linkRealPath}`);
        }
    }
}
/**
 * Synchronously ensures that the link exists, and points to a valid file.
 *
 * If the parent directories for the link do not exist, they are created. If the
 * link already exists, and it is not modified, this function does nothing. If
 * the link already exists, and it does not point to the given target, an error
 * is thrown.
 *
 * Requires `--allow-read` and `--allow-write` permissions.
 *
 * @see {@link https://docs.deno.com/runtime/manual/basics/permissions#file-system-access}
 * for more information on Deno's permissions system.
 *
 * @param target The source file path as a string or URL. If it is a relative path string, it have to be relative to the link path.
 * @param linkName The destination link path as a string or URL.
 * @returns A void value that returns once the link exists.
 *
 * @example Basic usage
 * ```ts ignore
 * import { ensureSymlinkSync } from "@std/fs/ensure-symlink";
 *
 * // Ensures the link `./targetFile.link.dat` exists and points to `./targetFile.dat`
 * ensureSymlinkSync("./targetFile.dat", "./targetFile.link.dat");
 * ```
 *
 * @example Ensuring a link in a folder
 * ```ts ignore
 * import { ensureSymlinkSync } from "@std/fs/ensure-symlink";
 *
 * // Ensures the link `./folder/targetFile.link.dat` exists and points to `./folder/targetFile.dat`
 * ensureSymlinkSync("./targetFile.dat", "./folder/targetFile.link.dat");
 * ```
 */
export function ensureSymlinkSync(target, linkName) {
    const targetRealPath = resolveSymlinkTarget(target, linkName);
    let srcStatInfo;
    try {
        srcStatInfo = dntShim.Deno.lstatSync(targetRealPath);
    }
    catch (error) {
        if (error instanceof dntShim.Deno.errors.NotFound) {
            throw new dntShim.Deno.errors.NotFound(`Cannot ensure symlink as the target path does not exist: ${targetRealPath}`);
        }
        throw error;
    }
    const srcFilePathType = getFileInfoType(srcStatInfo);
    ensureDirSync(dirname(toPathString(linkName)));
    const options = getSymlinkOption(srcFilePathType);
    try {
        dntShim.Deno.symlinkSync(target, linkName, options);
    }
    catch (error) {
        if (!(error instanceof dntShim.Deno.errors.AlreadyExists)) {
            throw error;
        }
        const linkStatInfo = dntShim.Deno.lstatSync(linkName);
        if (!linkStatInfo.isSymlink) {
            const type = getFileInfoType(linkStatInfo);
            throw new dntShim.Deno.errors.AlreadyExists(`A '${type}' already exists at the path: ${linkName}`);
        }
        const linkPath = dntShim.Deno.readLinkSync(linkName);
        const linkRealPath = resolve(linkPath);
        if (linkRealPath !== targetRealPath) {
            throw new dntShim.Deno.errors.AlreadyExists(`A symlink targeting to an undesired path already exists: ${linkName} -> ${linkRealPath}`);
        }
    }
}
