// What the guest npm prints, in npm 11.7.0's formats: display.js's log lines,
// reify-output.js's summary, error-message.js's explanation of an error, and the usage
// texts. Shared by every command.
import { homedir } from "node:os";
import { join } from "node:path";
import process from "node:process";
import type { InstallError, InstallReport } from "../shared/protocol";

export const VERSION = "11.7.0";
const started = Date.now();

/** display.js #writeLog: "npm <level>[ <title>]" before each line, a space only before text. */
export function logLines(level: "warn" | "error", title: string, text: string): string {
  const prefix = ["npm", level, title || null].filter((p) => p !== null).join(" ");
  return text.split(/\r?\n/).map((l) => `${prefix}${l ? " " : ""}${l}\n`).join("");
}

// The `ms` package's short format, as reify-output.js prints the time taken.
function ms(n: number): string {
  const units: Array<[number, string]> = [[86_400_000, "d"], [3_600_000, "h"], [60_000, "m"], [1000, "s"]];
  for (const [size, unit] of units) if (Math.abs(n) >= size) return `${Math.round(n / size)}${unit}`;
  return `${n}ms`;
}

const plural = (n: number, word: string): string => `${n} ${word}${n === 1 ? "" : "s"}`;

/** reify-output.js packagesChangedMessage, with nothing audited. */
export function changedMessage({ added, removed, changed }: InstallReport["diff"]): string {
  const msg = ["\n"];
  if (added === 0 && removed === 0 && changed === 0) msg.push("up to date");
  else {
    if (added) msg.push(`added ${plural(added, "package")}`);
    if (removed) {
      if (added) msg.push(", ");
      if (added && !changed) msg.push("and ");
      msg.push(`removed ${plural(removed, "package")}`);
    }
    if (changed) {
      if (added || removed) msg.push(", and ");
      msg.push(`changed ${plural(changed, "package")}`);
    }
  }
  msg.push(` in ${ms(Date.now() - started)}`);
  return `${msg.join("")}\n`;
}

export const CI_USAGE = `Clean install a project

Usage:
npm ci

Options:
[--install-strategy <hoisted|nested|shallow|linked>] [--legacy-bundling]
[--global-style] [--omit <dev|optional|peer> [--omit <dev|optional|peer> ...]]
[--include <prod|dev|optional|peer> [--include <prod|dev|optional|peer> ...]]
[--strict-peer-deps] [--foreground-scripts] [--ignore-scripts] [--no-audit]
[--no-bin-links] [--no-fund] [--dry-run]
[-w|--workspace <workspace-name> [-w|--workspace <workspace-name> ...]]
[--workspaces] [--include-workspace-root] [--install-links]

aliases: clean-install, ic, install-clean, isntall-clean

Run "npm help ci" for more info`;

const ERESOLVE_FIX = `Fix the upstream dependency conflict, or retry
this command with --force or --legacy-peer-deps
to accept an incorrect (and potentially broken) dependency resolution.`;

type Line = [title: string, ...text: string[]];

/** error-message.js errorMessage for the errors the installer raises: what npm logs as
 *  `npm error` after the error's own fields. */
function explain(er: InstallError): Line[] {
  switch (er.code) {
    case "ERESOLVE": {
      const at = er.message.indexOf("\n");
      const [head, rest] = at === -1 ? [er.message, ""] : [er.message.slice(0, at), er.message.slice(at + 1).replace(/^\n/, "")];
      return [["ERESOLVE", head], ["", ""], ["", `${rest}\n\n${ERESOLVE_FIX}`]];
    }
    case "E404": {
      const lines: Line[] = [["404", er.message.replace(/^404\s+/, "")]];
      if (er.pkgid && er.pkgid !== "-") {
        lines.push(
          ["404", ""],
          ["404", "", `The requested resource '${er.pkgid}' could not be found or you do not have permission to access it.`],
          ["404", ""], ["404", "Note that you can also install from a"], ["404", "tarball, folder, http url, or git url."],
        );
      }
      return lines;
    }
    case "ETARGET":
      return [["notarget", er.message], ["notarget", "In most cases you or one of your dependencies are requesting\na package version that doesn't exist."]];
    case "EBADPLATFORM":
      return [["notsup", er.message]];
    case "ENOENT":
      return [["enoent", er.message], ["enoent", "This is related to npm not being able to find a file.\n"]];
    default:
      return [["", er.message]];
  }
}

/** getError and outputError: the error's code, syscall, path and errno, then its explanation. */
function errorText(er: InstallError): string {
  const fields: Line[] = (["code", "syscall", "path", "errno"] as const)
    .filter((k) => er[k] !== undefined && er[k] !== "" && er[k] !== 0)
    .map((k) => [k, String(er[k])]);
  return [...fields, ...explain(er)].map(([title, ...text]) => logLines("error", title, text.join(" "))).join("");
}

export function usage(): string {
  return `npm <command>

Usage:

npm install        install all the dependencies in your project
npm install <foo>  add the <foo> dependency to your project
npm test           run this project's tests
npm run <foo>      run the script named <foo>
npm <command> -h   quick help on <command>
npm -l             display usage info for all commands
npm help <term>    search for help on <term>
npm help npm       more involved overview

All commands:

    access, adduser, audit, bugs, cache, ci, completion,
    config, dedupe, deprecate, diff, dist-tag, docs, doctor,
    edit, exec, explain, explore, find-dupes, fund, get, help,
    help-search, init, install, install-ci-test, install-test,
    link, ll, login, logout, ls, org, outdated, owner, pack,
    ping, pkg, prefix, profile, prune, publish, query, rebuild,
    repo, restart, root, run, sbom, search, set, shrinkwrap,
    star, stars, start, stop, team, test, token, undeprecate,
    uninstall, unpublish, unstar, update, version, view, whoami

Specify configs in the ini-formatted file:
    ${join(homedir(), ".npmrc")}
or on the command line via: npm <command> --key=value

More configuration info: npm help config
Configuration fields: npm help 7 config

npm@${VERSION} /usr/local/lib/node_modules/npm
`;
}

export const EXEC_USAGE = `Run a command from a local or remote npm package

Usage:
npm exec -- <pkg>[@<version>] [args...]
npm exec --package=<pkg>[@<version>] -- <cmd> [args...]
npm exec -c '<cmd> [args...]'
npm exec --package=foo -c '<cmd> [args...]'

Options:
[--package <package-spec> [--package <package-spec> ...]] [-c|--call <call>]
[-w|--workspace <workspace-name> [-w|--workspace <workspace-name> ...]]
[--workspaces] [--include-workspace-root]

alias: x

Run "npm help exec" for more info`;

/** An npm error, as a command throws it for main to print. */
export class NpmFailure extends Error {
  constructor(readonly error: InstallError) {
    super(error.message);
  }
}

export function fail(er: InstallError): void {
  process.stderr.write(errorText(er));
  // npm exits with the error's errno when it has one (ENOENT's -2 is 254), else 1.
  process.exitCode = (er.errno ?? 1) & 0xff || 1;
}