/**
 * @fileoverview Helper functions for ESLint class
 * @author Nicholas C. Zakas
 */

"use strict";

//-----------------------------------------------------------------------------
// Requirements
//-----------------------------------------------------------------------------

const path = require("path");
const fs = require("fs");
const fsp = fs.promises;
const isGlob = require("is-glob");
const globby = require("globby");
const hash = require("../cli-engine/hash");

//-----------------------------------------------------------------------------
// Errors
//-----------------------------------------------------------------------------

/**
 * The error type when no files match a glob.
 */
class NoFilesFoundError extends Error {

    /**
     * @param {string} pattern The glob pattern which was not found.
     * @param {boolean} globEnabled If `false` then the pattern was a glob pattern, but glob was disabled.
     */
    constructor(pattern, globEnabled) {
        super(`No files matching '${pattern}' were found${!globEnabled ? " (glob was disabled)" : ""}.`);
        this.messageTemplate = "file-not-found";
        this.messageData = { pattern, globDisabled: !globEnabled };
    }
}

/**
 * The error type when there are files matched by a glob, but all of them have been ignored.
 */
class AllFilesIgnoredError extends Error {

    /**
     * @param {string} pattern The glob pattern which was not found.
     */
    constructor(pattern) {
        super(`All files matched by '${pattern}' are ignored.`);
        this.messageTemplate = "all-files-ignored";
        this.messageData = { pattern };
    }
}


//-----------------------------------------------------------------------------
// General Helpers
//-----------------------------------------------------------------------------

/**
 * Check if a given value is a non-empty string or not.
 * @param {any} x The value to check.
 * @returns {boolean} `true` if `x` is a non-empty string.
 */
function isNonEmptyString(x) {
    return typeof x === "string" && x.trim() !== "";
}

/**
 * Check if a given value is an array of non-empty stringss or not.
 * @param {any} x The value to check.
 * @returns {boolean} `true` if `x` is an array of non-empty stringss.
 */
function isArrayOfNonEmptyString(x) {
    return Array.isArray(x) && x.every(isNonEmptyString);
}

//-----------------------------------------------------------------------------
// File-related Helpers
//-----------------------------------------------------------------------------

/**
 * Normalizes slashes in a file pattern to posix-style.
 * @param {string} pattern The pattern to replace slashes in.
 * @returns {string} The pattern with slashes normalized.
 */
function normalizeToPosix(pattern) {
    return pattern.replace(/\\/gu, "/");
}

/**
 * Check if a string is a glob pattern or not.
 * @param {string} pattern A glob pattern.
 * @returns {boolean} `true` if the string is a glob pattern.
 */
function isGlobPattern(pattern) {
    return isGlob(path.sep === "\\" ? normalizeToPosix(pattern) : pattern);
}

/**
 * Finds all files matching the options specified.
 * @param {Object} args The arguments objects.
 * @param {Array<string>} args.patterns An array of glob patterns.
 * @param {boolean} args.globInputPaths true to interpret glob patterns,
 *      false to not interpret glob patterns.
 * @param {string} args.cwd The current working directory to find from.
 * @param {FlatConfigArray} args.configs The configs for the current run.
 * @returns {Promise<Array<string>>} The fully resolved file paths.
 * @throws {AllFilesIgnoredError} If there are no results due to an ignore pattern.
 * @throws {NoFilesFoundError} If no files matched the given patterns.
 */
async function findFiles({
    patterns,
    globInputPaths,
    cwd,
    configs
}) {

    const results = [];
    const globbyPatterns = [];
    const missingPatterns = [];

    // check to see if we have explicit files and directories
    const filePaths = patterns.map(filePath => path.resolve(cwd, filePath));
    const stats = await Promise.all(
        filePaths.map(
            filePath => fsp.stat(filePath).catch(() => {})
        )
    );

    stats.forEach((stat, index) => {

        const filePath = filePaths[index];
        const pattern = patterns[index];

        if (stat) {

            // files are added directly to the list
            if (stat.isFile()) {
                results.push({
                    filePath,
                    ignored: configs.isIgnored(filePath)
                });
            }

            // directories need extensions attached
            if (stat.isDirectory()) {

                // filePatterns are all relative to cwd
                const filePatterns = configs.files
                    .filter(filePattern => {

                        // can only do this for strings, not functions
                        if (typeof filePattern !== "string") {
                            return false;
                        }

                        // patterns ending with * are not used for file search
                        if (filePattern.endsWith("*")) {
                            return false;
                        }

                        // not sure how to handle negated patterns yet
                        if (filePattern.startsWith("!")) {
                            return false;
                        }

                        // check if the pattern would be inside the cwd or not
                        const fullFilePattern = path.join(cwd, filePattern);
                        const relativeFilePattern = path.relative(configs.basePath, fullFilePattern);

                        return !relativeFilePattern.startsWith("..");
                    })
                    .map(filePattern => {
                        if (filePattern.startsWith("**")) {
                            return path.join(pattern, filePattern);
                        }

                        // adjust the path to be relative to the cwd
                        return path.relative(
                            cwd,
                            path.join(configs.basePath, filePattern)
                        );
                    })
                    .map(normalizeToPosix);

                if (filePatterns.length) {
                    globbyPatterns.push(...filePatterns);
                }

            }

            return;
        }

        // save patterns for later use based on whether globs are enabled
        if (globInputPaths && isGlobPattern(filePath)) {
            globbyPatterns.push(pattern);
        } else {
            missingPatterns.push(pattern);
        }
    });

    // note: globbyPatterns can be an empty array
    const globbyResults = (await globby(globbyPatterns, {
        cwd,
        absolute: true,
        ignore: configs.ignores.filter(matcher => typeof matcher === "string")
    }));

    // if there are no results, tell the user why
    if (!results.length && !globbyResults.length) {

        // try globby without ignoring anything
        /* eslint-disable no-unreachable-loop -- We want to exit early. */
        for (const globbyPattern of globbyPatterns) {

            /* eslint-disable-next-line no-unused-vars -- Want to exit early. */
            for await (const filePath of globby.stream(globbyPattern, { cwd, absolute: true })) {

                // files were found but ignored
                throw new AllFilesIgnoredError(globbyPattern);
            }

            // no files were found
            throw new NoFilesFoundError(globbyPattern, globInputPaths);
        }
        /* eslint-enable no-unreachable-loop -- Go back to normal. */

    }

    // there were patterns that didn't match anything, tell the user
    if (missingPatterns.length) {
        throw new NoFilesFoundError(missingPatterns[0], globInputPaths);
    }


    return [
        ...results,
        ...globbyResults.map(filePath => ({
            filePath: path.resolve(filePath),
            ignored: false
        }))
    ];
}


/**
 * Checks whether a file exists at the given location
 * @param {string} resolvedPath A path from the CWD
 * @throws {Error} As thrown by `fs.statSync` or `fs.isFile`.
 * @returns {boolean} `true` if a file exists
 */
function fileExists(resolvedPath) {
    try {
        return fs.statSync(resolvedPath).isFile();
    } catch (error) {
        if (error && (error.code === "ENOENT" || error.code === "ENOTDIR")) {
            return false;
        }
        throw error;
    }
}

/**
 * Checks whether a directory exists at the given location
 * @param {string} resolvedPath A path from the CWD
 * @throws {Error} As thrown by `fs.statSync` or `fs.isDirectory`.
 * @returns {boolean} `true` if a directory exists
 */
function directoryExists(resolvedPath) {
    try {
        return fs.statSync(resolvedPath).isDirectory();
    } catch (error) {
        if (error && (error.code === "ENOENT" || error.code === "ENOTDIR")) {
            return false;
        }
        throw error;
    }
}

//-----------------------------------------------------------------------------
// Results-related Helpers
//-----------------------------------------------------------------------------

/**
 * Checks if the given message is an error message.
 * @param {LintMessage} message The message to check.
 * @returns {boolean} Whether or not the message is an error message.
 * @private
 */
function isErrorMessage(message) {
    return message.severity === 2;
}

/**
 * Returns result with warning by ignore settings
 * @param {string} filePath File path of checked code
 * @param {string} baseDir Absolute path of base directory
 * @returns {LintResult} Result with single warning
 * @private
 */
function createIgnoreResult(filePath, baseDir) {
    let message;
    const isHidden = filePath.split(path.sep)
        .find(segment => /^\./u.test(segment));
    const isInNodeModules = baseDir && path.relative(baseDir, filePath).startsWith("node_modules");

    if (isHidden) {
        message = "File ignored by default.  Use a negated ignore pattern (like \"--ignore-pattern '!<relative/path/to/filename>'\") to override.";
    } else if (isInNodeModules) {
        message = "File ignored by default. Use \"--ignore-pattern '!node_modules/*'\" to override.";
    } else {
        message = "File ignored because of a matching ignore pattern. Use \"--no-ignore\" to override.";
    }

    return {
        filePath: path.resolve(filePath),
        messages: [
            {
                fatal: false,
                severity: 1,
                message
            }
        ],
        errorCount: 0,
        warningCount: 1,
        fatalErrorCount: 0,
        fixableErrorCount: 0,
        fixableWarningCount: 0
    };
}

//-----------------------------------------------------------------------------
// Options-related Helpers
//-----------------------------------------------------------------------------


/**
 * Check if a given value is a valid fix type or not.
 * @param {any} x The value to check.
 * @returns {boolean} `true` if `x` is valid fix type.
 */
function isFixType(x) {
    return x === "directive" || x === "problem" || x === "suggestion" || x === "layout";
}

/**
 * Check if a given value is an array of fix types or not.
 * @param {any} x The value to check.
 * @returns {boolean} `true` if `x` is an array of fix types.
 */
function isFixTypeArray(x) {
    return Array.isArray(x) && x.every(isFixType);
}

/**
 * The error for invalid options.
 */
class ESLintInvalidOptionsError extends Error {
    constructor(messages) {
        super(`Invalid Options:\n- ${messages.join("\n- ")}`);
        this.code = "ESLINT_INVALID_OPTIONS";
        Error.captureStackTrace(this, ESLintInvalidOptionsError);
    }
}

/**
 * Validates and normalizes options for the wrapped CLIEngine instance.
 * @param {FlatESLintOptions} options The options to process.
 * @throws {ESLintInvalidOptionsError} If of any of a variety of type errors.
 * @returns {FlatESLintOptions} The normalized options.
 */
function processOptions({
    allowInlineConfig = true, // ← we cannot use `overrideConfig.noInlineConfig` instead because `allowInlineConfig` has side-effect that suppress warnings that show inline configs are ignored.
    baseConfig = null,
    cache = false,
    cacheLocation = ".eslintcache",
    cacheStrategy = "metadata",
    cwd = process.cwd(),
    errorOnUnmatchedPattern = true,
    extensions = null, // ← should be null by default because if it's an array then it suppresses RFC20 feature.
    fix = false,
    fixTypes = null, // ← should be null by default because if it's an array then it suppresses rules that don't have the `meta.type` property.
    globInputPaths = true,
    ignore = true,
    ignorePath = null, // ← should be null by default because if it's a string then it may throw ENOENT.
    ignorePatterns = null,
    overrideConfig = null,
    overrideConfigFile = null,
    plugins = {},
    reportUnusedDisableDirectives = null, // ← should be null by default because if it's a string then it overrides the 'reportUnusedDisableDirectives' setting in config files. And we cannot use `overrideConfig.reportUnusedDisableDirectives` instead because we cannot configure the `error` severity with that.
    ...unknownOptions
}) {
    const errors = [];
    const unknownOptionKeys = Object.keys(unknownOptions);

    if (unknownOptionKeys.length >= 1) {
        errors.push(`Unknown options: ${unknownOptionKeys.join(", ")}`);
        if (unknownOptionKeys.includes("cacheFile")) {
            errors.push("'cacheFile' has been removed. Please use the 'cacheLocation' option instead.");
        }
        if (unknownOptionKeys.includes("configFile")) {
            errors.push("'configFile' has been removed. Please use the 'overrideConfigFile' option instead.");
        }
        if (unknownOptionKeys.includes("envs")) {
            errors.push("'envs' has been removed.");
        }
        if (unknownOptionKeys.includes("resolvePluginsRelativeTo")) {
            errors.push("'resolvePluginsRelativeTo' has been removed.");
        }
        if (unknownOptionKeys.includes("globals")) {
            errors.push("'globals' has been removed. Please use the 'overrideConfig.languageOptions.globals' option instead.");
        }
        if (unknownOptionKeys.includes("ignorePattern")) {
            errors.push("'ignorePattern' has been removed. Please use the 'overrideConfig.ignorePatterns' option instead.");
        }
        if (unknownOptionKeys.includes("parser")) {
            errors.push("'parser' has been removed. Please use the 'overrideConfig.languageOptions.parser' option instead.");
        }
        if (unknownOptionKeys.includes("parserOptions")) {
            errors.push("'parserOptions' has been removed. Please use the 'overrideConfig.languageOptions.parserOptions' option instead.");
        }
        if (unknownOptionKeys.includes("rules")) {
            errors.push("'rules' has been removed. Please use the 'overrideConfig.rules' option instead.");
        }
        if (unknownOptionKeys.includes("rulePaths")) {
            errors.push("'rulePaths' has been removed. Please define your rules using plugins.");
        }
    }
    if (typeof allowInlineConfig !== "boolean") {
        errors.push("'allowInlineConfig' must be a boolean.");
    }
    if (typeof baseConfig !== "object") {
        errors.push("'baseConfig' must be an object or null.");
    }
    if (typeof cache !== "boolean") {
        errors.push("'cache' must be a boolean.");
    }
    if (cache) {
        errors.push("'cache' option is not yet supported.");
    }
    if (!isNonEmptyString(cacheLocation)) {
        errors.push("'cacheLocation' must be a non-empty string.");
    }
    if (
        cacheStrategy !== "metadata" &&
        cacheStrategy !== "content"
    ) {
        errors.push("'cacheStrategy' must be any of \"metadata\", \"content\".");
    }
    if (!isNonEmptyString(cwd) || !path.isAbsolute(cwd)) {
        errors.push("'cwd' must be an absolute path.");
    }
    if (typeof errorOnUnmatchedPattern !== "boolean") {
        errors.push("'errorOnUnmatchedPattern' must be a boolean.");
    }
    if (!isArrayOfNonEmptyString(extensions) && extensions !== null) {
        errors.push("'extensions' must be an array of non-empty strings or null.");
    }
    if (typeof fix !== "boolean" && typeof fix !== "function") {
        errors.push("'fix' must be a boolean or a function.");
    }
    if (fixTypes !== null && !isFixTypeArray(fixTypes)) {
        errors.push("'fixTypes' must be an array of any of \"directive\", \"problem\", \"suggestion\", and \"layout\".");
    }
    if (typeof globInputPaths !== "boolean") {
        errors.push("'globInputPaths' must be a boolean.");
    }
    if (typeof ignore !== "boolean") {
        errors.push("'ignore' must be a boolean.");
    }
    if (!isNonEmptyString(ignorePath) && ignorePath !== null) {
        errors.push("'ignorePath' must be a non-empty string or null.");
    }
    if (typeof overrideConfig !== "object") {
        errors.push("'overrideConfig' must be an object or null.");
    }
    if (!isNonEmptyString(overrideConfigFile) && overrideConfigFile !== null && overrideConfigFile !== true) {
        errors.push("'overrideConfigFile' must be a non-empty string, null, or true.");
    }
    if (typeof plugins !== "object") {
        errors.push("'plugins' must be an object or null.");
    } else if (plugins !== null && Object.keys(plugins).includes("")) {
        errors.push("'plugins' must not include an empty string.");
    }
    if (Array.isArray(plugins)) {
        errors.push("'plugins' doesn't add plugins to configuration to load. Please use the 'overrideConfig.plugins' option instead.");
    }
    if (
        reportUnusedDisableDirectives !== "error" &&
        reportUnusedDisableDirectives !== "warn" &&
        reportUnusedDisableDirectives !== "off" &&
        reportUnusedDisableDirectives !== null
    ) {
        errors.push("'reportUnusedDisableDirectives' must be any of \"error\", \"warn\", \"off\", and null.");
    }
    if (errors.length > 0) {
        throw new ESLintInvalidOptionsError(errors);
    }

    return {
        allowInlineConfig,
        baseConfig,
        cache,
        cacheLocation,
        cacheStrategy,

        // when overrideConfigFile is true that means don't do config file lookup
        configFile: overrideConfigFile === true ? false : overrideConfigFile,
        overrideConfig,
        cwd,
        errorOnUnmatchedPattern,
        extensions,
        fix,
        fixTypes,
        globInputPaths,
        ignore,
        ignorePath,
        ignorePatterns,
        reportUnusedDisableDirectives
    };
}


//-----------------------------------------------------------------------------
// Cache-related helpers
//-----------------------------------------------------------------------------

/**
 * return the cacheFile to be used by eslint, based on whether the provided parameter is
 * a directory or looks like a directory (ends in `path.sep`), in which case the file
 * name will be the `cacheFile/.cache_hashOfCWD`
 *
 * if cacheFile points to a file or looks like a file then in will just use that file
 * @param {string} cacheFile The name of file to be used to store the cache
 * @param {string} cwd Current working directory
 * @returns {string} the resolved path to the cache file
 */
function getCacheFile(cacheFile, cwd) {

    /*
     * make sure the path separators are normalized for the environment/os
     * keeping the trailing path separator if present
     */
    const normalizedCacheFile = path.normalize(cacheFile);

    const resolvedCacheFile = path.resolve(cwd, normalizedCacheFile);
    const looksLikeADirectory = normalizedCacheFile.slice(-1) === path.sep;

    /**
     * return the name for the cache file in case the provided parameter is a directory
     * @returns {string} the resolved path to the cacheFile
     */
    function getCacheFileForDirectory() {
        return path.join(resolvedCacheFile, `.cache_${hash(cwd)}`);
    }

    let fileStats;

    try {
        fileStats = fs.lstatSync(resolvedCacheFile);
    } catch {
        fileStats = null;
    }


    /*
     * in case the file exists we need to verify if the provided path
     * is a directory or a file. If it is a directory we want to create a file
     * inside that directory
     */
    if (fileStats) {

        /*
         * is a directory or is a file, but the original file the user provided
         * looks like a directory but `path.resolve` removed the `last path.sep`
         * so we need to still treat this like a directory
         */
        if (fileStats.isDirectory() || looksLikeADirectory) {
            return getCacheFileForDirectory();
        }

        // is file so just use that file
        return resolvedCacheFile;
    }

    /*
     * here we known the file or directory doesn't exist,
     * so we will try to infer if its a directory if it looks like a directory
     * for the current operating system.
     */

    // if the last character passed is a path separator we assume is a directory
    if (looksLikeADirectory) {
        return getCacheFileForDirectory();
    }

    return resolvedCacheFile;
}


//-----------------------------------------------------------------------------
// Exports
//-----------------------------------------------------------------------------

module.exports = {
    isGlobPattern,
    directoryExists,
    fileExists,
    findFiles,

    isNonEmptyString,
    isArrayOfNonEmptyString,

    createIgnoreResult,
    isErrorMessage,

    processOptions,

    getCacheFile
};