import { spawnSync, SpawnSyncOptionsWithStringEncoding } from 'child_process';

export const BuiltInList = [
  '[',
  '_',
  'abbr',
  'and',
  'argparse',
  'begin',
  'bg',
  'bind',
  'block',
  'break',
  'breakpoint',
  'builtin',
  'case',
  'cd',
  'command',
  'commandline',
  'complete',
  'contains',
  'continue',
  'count',
  'disown',
  'echo',
  'else',
  'emit',
  'end',
  'eval',
  'exec',
  'exit',
  'false',
  'fg',
  'for',
  'function',
  'functions',
  'history',
  'if',
  'jobs',
  'math',
  'not',
  'or',
  'path',
  'printf',
  'pwd',
  'random',
  'read',
  'realpath',
  'return',
  'set',
  'set_color',
  'source',
  'status',
  'string',
  'switch',
  'test',
  'time',
  'true',
  'type',
  'ulimit',
  'wait',
  'while',
];

// You can generate this list by running `builtin --names` in a fish session
// note that '.', and ':' are removed from the list because they do not contain
// a man-page
const BuiltInSET = new Set(BuiltInList);

// check if string is one of the default fish builtin functions
export function isBuiltin(word: string): boolean {
  return BuiltInSET.has(word);
}

const reservedKeywords = [
  '[',
  '_',
  'and',
  'argparse',
  'begin',
  'break',
  'builtin',
  'case',
  'command',
  'continue',
  'else',
  'end',
  'eval',
  'exec',
  'for',
  'function',
  'if',
  'not',
  'or',
  'read',
  'return',
  'set',
  'status',
  'string',
  'switch',
  'test',
  'time',
  'and',
  'while',
];
const ReservedKeywordSet = new Set(reservedKeywords);
// Reserved keywords are not allowed as function names.
// Found on the `function` manpage.
export function isReservedKeyword(word: string): boolean {
  return ReservedKeywordSet.has(word);
}

export function findShell() {
  const result = spawnSync('which fish', { shell: true, stdio: ['ignore', 'pipe', 'inherit'], encoding: 'utf-8' });
  return result.stdout.toString().trim();
}
const fishShell = findShell();

const spawnOpts: SpawnSyncOptionsWithStringEncoding = {
  shell: fishShell,
  stdio: ['ignore', 'pipe', 'inherit'],
  encoding: 'utf-8',
};

function createFunctionNamesList() {
  const result = spawnSync('functions --names | string split -n \'\\n\'', spawnOpts);
  return result.stdout.toString().split('\n');
}
export const FunctionNamesList = createFunctionNamesList();
export function isFunction(word: string): boolean {
  return FunctionNamesList.includes(word);
}
function createFunctionEventsList() {
  const result = spawnSync('functions --handlers | string match -vr \'^Event \\w+\' | string split -n \'\\n\'', spawnOpts);
  return result.stdout.toString().split('\n');
}

export const EventNamesList = createFunctionEventsList();
export function isEvent(word: string): boolean {
  return EventNamesList.includes(word);
}

function createAbbrList() {
  const { stdout } = spawnSync('abbr --show', spawnOpts);
  return stdout.toString().split('\n');
}
export const AbbrList = createAbbrList();

function createGlobalVariableList() {
  const { stdout } = spawnSync('set -n', spawnOpts);
  return stdout.toString().split('\n');
}

export const GlobalVariableList = createGlobalVariableList();

//function createAliasList() {
//    // `alias | string unescape | string shorten -m 100`
//    const {stdout} = spawnSync(`alias | string unescape --style=var | string split -n '\\n'`, spawnOpts)
//    return stdout.toString().split('\n')
//}
//export const AliasList = createAliasList()

// cd /usr/share/fish/completions/
// for i in (rg -e '-a' -l); echo (string split -f 1 '.fish' -m1 $i);end
// commands with potential subcommands
//  • string split ...
//  • killall node
//  • man vim
//  • command fish

// useful when checking the current Command for documentation/completion
// suggestions. If a match is hit, check one more node back, and if it is
// not a command, stop searching backwards.
// export function hasPossibleSubCommand(cmd: string) : boolean {
//   return SubCommandSet.has(cmd);
// }

// const PossibleSubCommand = [
// ];

// const SubCommandSet = new Set(...PossibleSubCommand);