'use strict'
// load all defined plugins

// node built-ins
const fs = require('node:fs')
const path = require('node:path')
const vm = require('node:vm')

// npm modules
exports.config = require('haraka-config')
const constants = require('haraka-constants')

// local modules
const logger = require('./logger')

exports.registered_hooks = {}
exports.registered_plugins = {}
exports.plugin_list = []

let order = 0

class Plugin {
    constructor(name) {
        this.name = name
        this.base = {}
        this.timeout = get_timeout(name)
        this._get_plugin_path()
        this.config = this._get_config()
        this.hooks = {}
    }

    haraka_require(name) {
        return require(`./${name}`)
    }

    _get_plugin_path() {
        /* From https://github.com/haraka/Haraka/pull/1278#issuecomment-168856528
        In Development mode, or install via a plain "git clone":

            Plain plugin in plugins/ folder
            Plugin in a folder in plugins/<name>/ folder. Contains a package.json.
            Plugin in node_modules. Contains a package.json file.

        In "installed" mode (via haraka -i <path>):

            Plain plugin in <path>/plugins/ folder
            Plugin in a folder in <path>/plugins/<name>/folder. (same concept as above)
            Plugin in <path>/node_modules. Contains a package.json file.
            Core plugin in <core_haraka_dir>/plugins/ folder
            Plugin in a folder in <core_haraka_dir>/plugins/<name>/ folder. (same concept as above)
            Plugin in <core_haraka_dir>/node_modules.
        */

        this.hasPackageJson = false
        const name = this.name.startsWith('haraka-plugin-') ? this.name.slice(14) : this.name
        if (this.name !== name) this.name = name

        let paths = []
        if (process.env.HARAKA) {
            // Installed mode - started via bin/haraka
            paths = [...paths, ...plugin_search_paths(process.env.HARAKA, name)]

            // permit local "folder" plugins (/$name/package.json) (see #1649)
            paths.push(
                path.resolve(process.env.HARAKA, 'plugins', name, 'package.json'),
                path.resolve(process.env.HARAKA, 'node_modules', name, 'package.json'),
            )
        }

        // development mode
        paths = [...paths, ...plugin_search_paths(__dirname, name)]
        for (const pp of paths) {
            if (this.plugin_path) continue
            try {
                fs.statSync(pp)
                this.plugin_path = pp
                if (path.basename(pp) === 'package.json') {
                    this.hasPackageJson = true
                }
            } catch (ignore) {}
        }
    }

    _get_config() {
        if (this.hasPackageJson) {
            // It's a package/folder plugin - look in plugin folder for defaults,
            // haraka/config folder for overrides
            return exports.config.module_config(path.dirname(this.plugin_path), process.env.HARAKA || __dirname)
        }

        if (process.env.HARAKA) {
            // Plain .js file, installed mode - look in core folder for defaults,
            // install dir for overrides
            return exports.config.module_config(__dirname, process.env.HARAKA)
        }

        if (process.env.HARAKA_TEST_DIR) {
            return exports.config.module_config(process.env.HARAKA_TEST_DIR)
        }

        // Plain .js file, git mode - just look in this folder
        return exports.config.module_config(__dirname)
    }

    register_hook(hook_name, method_name, priority) {
        priority = parseInt(priority)
        if (!priority) priority = 0
        if (priority > 100) priority = 100
        if (priority < -100) priority = -100

        if (!Array.isArray(exports.registered_hooks[hook_name])) {
            exports.registered_hooks[hook_name] = []
        }
        exports.registered_hooks[hook_name].push({
            plugin: this.name,
            method: method_name,
            priority,
            timeout: this.timeout,
            order: order++,
        })
        this.hooks[hook_name] = this.hooks[hook_name] || []
        this.hooks[hook_name].push(method_name)

        plugins.logdebug(`registered hook ${hook_name} to ${this.name}.${method_name} priority ${priority}`)
    }

    register() {} // noop

    inherits(parent_name) {
        const parent_plugin = plugins._load_and_compile_plugin(parent_name)
        for (const method in parent_plugin) {
            if (!this[method]) {
                this[method] = parent_plugin[method]
            }
        }
        if (parent_plugin.register) {
            parent_plugin.register.call(this)
        }
        this.base[parent_name] = parent_plugin
    }

    _make_custom_require() {
        return (module) => {
            if (this.hasPackageJson) {
                const mod = require(module)
                constants.import(global)
                global.server = plugins.server
                return mod
            }

            if (module === './config') {
                return this.config
            }

            if (!/^\./.test(module)) {
                return require(module)
            }

            for (const ext of [`${module}.js`, module]) {
                if (fs.existsSync(path.join(__dirname, ext))) {
                    return require(module)
                }
            }

            return require(path.join(path.dirname(this.plugin_path), module))
        }
    }

    _get_code(pi_path) {
        if (this.hasPackageJson) {
            let packageDir = path.dirname(pi_path)
            if (/^win(32|64)/.test(process.platform)) {
                // escape the c:\path\back\slashes else they disappear
                packageDir = packageDir.replace(/\\/g, '\\\\')
            }
            return `const _p = require("${packageDir}"); for (const k in _p) { exports[k] = _p[k] }`
        }

        try {
            return `"use strict";${fs.readFileSync(pi_path)}`
        } catch (err) {
            if (exports.config.get('smtp.ini').main.ignore_bad_plugins) {
                plugins.logcrit(`Loading ${this.name} failed: ${err}`)
                return
            }
            throw `Loading plugin ${this.name} failed: ${err}`
        }
    }

    _compile() {
        const pp = this.plugin_path
        const code = this._get_code(pp)
        if (!code) return

        const sandbox = {
            require: this._make_custom_require(),
            __filename: pp,
            __dirname: path.dirname(pp),
            exports: this,
            fetch,
            clearTimeout,
            clearInterval,
            process,
            setInterval,
            setTimeout,
            Buffer,
            Math,
            server: plugins.server,
            setImmediate,
        }
        if (this.hasPackageJson) {
            delete sandbox.__filename
        }
        constants.import(sandbox)
        try {
            vm.runInNewContext(code, sandbox, pp)
        } catch (err) {
            plugins.logcrit(`compiling '${this.name}' failed`)
            if (exports.config.get('smtp.ini').main.ignore_bad_plugins) {
                plugins.logcrit(`Loading '${this.name}' failed: ${err.message} - skipping`)
                return
            }
            throw err // default is to re-throw and stop Haraka
        }
    }
}

exports.shutdown_plugins = () => {
    for (const i in exports.registered_plugins) {
        if (exports.registered_plugins[i].shutdown) {
            exports.registered_plugins[i].shutdown()
        }
    }
}

process.on('message', (msg) => {
    if (msg.event && msg.event == 'plugins.shutdown') {
        plugins.loginfo('Shutting down')
        exports.shutdown_plugins()
    }
})

function plugin_search_paths(prefix, name) {
    return [
        // Haraka/plugins/*.js
        path.resolve(prefix, 'plugins', `${name}.js`),

        // Haraka/node_modules/haraka-plugin-*/package.json
        path.resolve(prefix, 'node_modules', `haraka-plugin-${name}`, 'package.json'),

        // global node_modules/haraka-plugin-*/package.json
        path.resolve(prefix, '..', `haraka-plugin-${name}`, 'package.json'),
    ]
}

function get_timeout(name) {
    let timeout = parseFloat(exports.config.get(`${name}.timeout`))
    if (isNaN(timeout)) {
        plugins.logdebug(`no timeout in ${name}.timeout`)
        timeout = parseFloat(exports.config.get('plugin_timeout'))
    }
    if (isNaN(timeout)) {
        plugins.logdebug('no timeout in plugin_timeout')
        timeout = 30
    }

    plugins.logdebug(`plugin ${name} timeout is: ${timeout}s`)
    return timeout
}

logger.add_log_methods(Plugin)

const plugins = exports

logger.add_log_methods(plugins, 'plugins')

plugins.Plugin = Plugin

plugins.load_plugins = (override) => {
    plugins.logdebug('Loading')
    let plugin_list
    if (override) {
        if (!Array.isArray(override)) override = [override]
        plugin_list = override
    } else {
        plugin_list = exports.config.get('plugins', 'list')
    }

    for (let plugin of plugin_list) {
        if (plugin.startsWith('haraka-plugin-')) plugin = plugin.substring(14)
        if (plugins.deprecated[plugin]) {
            plugins.lognotice(
                `${plugin} has been replaced by '${plugins.deprecated[plugin]}'. Please update config/plugins`,
            )
            plugins.load_plugin(plugins.deprecated[plugin])
        } else {
            plugins.load_plugin(plugin)
        }
    }

    plugins.plugin_list = Object.keys(plugins.registered_plugins)

    // Sort registered_hooks by priority
    for (const hook of Object.keys(plugins.registered_hooks)) {
        plugins.registered_hooks[hook].sort((a, b) => {
            if (a.priority < b.priority) return -1
            if (a.priority > b.priority) return 1
            if (a.priority == b.priority) {
                if (a.order > b.order) return 1
                return -1
            }
            return 0
        })
    }

    logger.dump_logs() // now logging plugins are loaded.
}

plugins.deprecated = {
    'auth/auth_ldap': 'auth-ldap',
    backscatterer: 'dns-list',
    'connect.asn': 'asn',
    'connect.fcrdns': 'fcrdns',
    'connect.geoip': 'geoip',
    'connect.p0f': 'p0f',
    'connect.rdns_access': 'access',
    'data.nomsgid': 'headers',
    'data.noreceived': 'headers',
    'data.rfc5322_header_checks': 'headers',
    'data.headers': 'headers',
    dkim_sign: 'dkim',
    dkim_verify: 'dkim',
    'data.uribl': 'uribl',
    dnsbl: 'dns-list',
    dnswl: 'dns-list',
    'log.syslog': 'syslog',
    'mail_from.access': 'access',
    'mail_from.blocklist': 'access',
    'mail_from.nobounces': 'bounce',
    max_unrecognized_commands: 'limit',
    rate_limit: 'limit',
    'rcpt_to.access': 'access',
    'rcpt_to.blocklist': 'access',
    'rcpt_to.ldap': 'rcpt-ldap',
    'rcpt_to.max_count': 'limit',
    'rcpt_to.qmail_deliverable': 'qmail-deliverable',
    'rdns.regexp': 'access',
    relay_acl: 'relay',
    relay_all: 'relay',
    relay_force_routing: 'relay',
}

plugins.load_plugin = (name) => {
    plugins.loginfo(`loading ${name}`)

    const plugin = plugins._load_and_compile_plugin(name)
    if (plugin) {
        plugins._register_plugin(plugin)
    }

    plugins.registered_plugins[name] = plugin
}

// Set in server.js; initialized to empty object
// to prevent it from blowing up any unit tests.
plugins.server = { notes: {} }

plugins._load_and_compile_plugin = (name) => {
    const plugin = new Plugin(name)
    if (!plugin.plugin_path) {
        const err = `Loading plugin ${plugin.name} failed: No plugin with this name found`
        if (exports.config.get('smtp.ini').main.ignore_bad_plugins) {
            plugins.logcrit(err)
            return
        }
        throw err
    }
    plugin._compile()
    return plugin
}

plugins._register_plugin = (plugin) => {
    plugin.register()

    // register any hook_blah methods.
    for (const method in plugin) {
        const result = method.match(/^hook_(\w+)\b/)
        if (result) {
            plugin.register_hook(result[1], method)
        }
    }
}

plugins.run_hooks = (hook, object, params) => {
    if (client_disconnected(object) && !is_required_hook(hook)) {
        object.logdebug(`aborting ${hook} hook`)
        return
    }

    if (hook !== 'log') object.logdebug(`running ${hook} hooks`)

    if (is_required_hook(hook) && object.current_hook) {
        object.current_hook[2]() // call cancel function
    }

    if (!is_required_hook(hook) && hook !== 'deny' && object.hooks_to_run && object.hooks_to_run.length) {
        throw new Error('We are already running hooks! Fatal error!')
    }

    if (hook === 'deny') {
        // Save the hooks_to_run list so that we can run any remaining
        // plugins on the previous hook once this hook is complete.
        object.saved_hooks_to_run = object.hooks_to_run
    }
    object.hooks_to_run = []

    if (plugins.registered_hooks[hook]) {
        for (const item of plugins.registered_hooks[hook]) {
            const plugin = plugins.registered_plugins[item.plugin]
            object.hooks_to_run.push([plugin, item.method])
        }
    }

    plugins.run_next_hook(hook, object, params)
}

plugins.run_next_hook = (hook, object, params) => {
    if (client_disconnected(object) && !is_required_hook(hook)) {
        object.logdebug(`aborting ${hook} hook`)
        return
    }
    let called_once = false
    let timeout_id
    let timed_out = false
    let cancelled = false
    let item

    function cancel() {
        if (timeout_id) clearTimeout(timeout_id)
        cancelled = true
    }
    function callback(retval, msg) {
        if (timeout_id) clearTimeout(timeout_id)
        object.current_hook = null
        if (cancelled) return // This hook has been cancelled

        // Bail if client has disconnected
        if (client_disconnected(object) && !is_required_hook(hook)) {
            object.logdebug(`ignoring ${item[0].name} plugin callback`)
            return
        }
        if (called_once && hook !== 'log') {
            if (!timed_out) {
                object.logerror(
                    `${item[0].name} plugin ran callback multiple times - ignoring subsequent calls`,
                    new Error(),
                )
            }
            return
        }
        called_once = true
        if (!retval) retval = constants.cont

        log_run_item(item, hook, retval, object, params, msg)

        if (object.hooks_to_run.length !== 0) {
            if (retval === constants.cont) {
                return plugins.run_next_hook(hook, object, params)
            }
            if (hook === 'connect_init' || hook === 'disconnect') {
                // these hooks ignore retval and always run for every plugin
                return plugins.run_next_hook(hook, object, params)
            }
        }

        const respond_method = `${hook}_respond`
        if (item && is_deny_retval(retval) && hook.substring(0, 5) !== 'init_') {
            object.deny_respond = get_denyfn(object, hook, params, retval, msg, respond_method)
            plugins.run_hooks('deny', object, [retval, msg, item[0].name, item[1], params, hook])
        } else {
            object.hooks_to_run = []
            object[respond_method](retval, msg, params)
        }
    }

    if (!object.hooks_to_run.length) return callback()

    // shift the next one off the stack and run it.
    item = object.hooks_to_run.shift()
    item.push(cancel)

    if (hook !== 'log' && item[0].timeout) {
        timeout_id = setTimeout(() => {
            timed_out = true
            object.logcrit(`Plugin ${item[0].name} timed out on hook ${hook} - make sure it calls the callback`)
            callback(constants.denysoft, 'plugin timeout')
        }, item[0].timeout * 1000)
    }

    if (hook !== 'log') {
        object.logdebug(`running ${hook} hook in ${item[0].name} plugin`)
    }

    if (object.transaction?.notes.skip_plugins.includes(item[0].name)) {
        object.logdebug(`skipping ${item[0].name}_${hook} by request in notes`)
        return callback()
    }

    try {
        object.current_hook = item
        object.hook = hook
        item[0][item[1]].call(item[0], callback, object, params)
    } catch (err) {
        if (hook !== 'log') {
            object.logcrit(`Plugin ${item[0].name} failed:`, err)
        }
        callback()
    }
}

function client_disconnected(object) {
    if (object.constructor.name === 'Connection' && object.state >= constants.connection.state.DISCONNECTING) {
        object.logdebug('client has disconnected')
        return true
    }
    return false
}

function is_required_hook(hook) {
    // Hooks that must always run
    switch (hook) {
        case 'reset_transaction':
        case 'disconnect':
        case 'log':
            return true
        default:
            return false
    }
}

function log_run_item(item, hook, retval, object, params, msg) {
    if (!item) return
    if (hook === 'log') return

    let log = 'logdebug'
    const is_not_cont = retval !== constants.cont && logger.would_log(logger.LOGINFO)
    if (is_not_cont) log = 'loginfo'
    if (is_not_cont || logger.would_log(logger.LOGDEBUG)) {
        object[log]({
            hook,
            plugin: item[0].name,
            function: item[1],
            params: params ? (typeof params === 'string' ? params : params[0]) : '',
            retval: constants.translate(retval),
            msg: sanitize(msg),
        })
    }
}

function sanitize(msg) {
    if (!msg) return ''
    if (typeof msg === 'string') return msg
    if (typeof msg === 'object') {
        if (msg.constructor.name === 'DSN') return msg.reply
        const sanitized = { ...msg } // copy the message
        for (const priv of ['password', 'auth_pass']) {
            delete sanitized[priv]
        }
        return JSON.stringify(sanitized)
    }
    logger.logerror(`what is ${msg} (typeof ${typeof msg})?`)
}

function is_deny_retval(val) {
    switch (val) {
        case constants.deny:
        case constants.denysoft:
        case constants.denydisconnect:
        case constants.denysoftdisconnect:
            return true
    }
    return false
}

function get_denyfn(object, hook, params, retval, msg, respond_method) {
    return (deny_retval, deny_msg) => {
        switch (deny_retval) {
            case constants.ok:
                // Override rejection
                object.loginfo(`deny(soft?) overridden by deny hook${deny_msg ? ': deny_msg' : ''}`)
                // Restore hooks_to_run with saved copy so that
                // any other plugins on this hook can also run.
                if (object.saved_hooks_to_run.length > 0) {
                    object.hooks_to_run = object.saved_hooks_to_run
                    plugins.run_next_hook(hook, object, params)
                } else {
                    object[respond_method](constants.cont, deny_msg, params)
                }
                break
            default:
                object.saved_hooks_to_run = []
                object.hooks_to_run = []
                object[respond_method](retval, msg, params)
        }
    }
}