// Settings for the process-global LDAPS listener (enable / bind host / port).
//
// There is ONE listener per Saltcorn instance, shared by all tenants (see
// lib/ldap/tenant.js), so its settings are INSTANCE-global, not per-tenant: they
// live in the ROOT (public) tenant's _sc_config and are edited from the admin
// panel on the public site. The SALTCORN_IDP_LDAP_PORT / SALTCORN_IDP_LDAP_HOST
// environment variables, WHEN SET, override the stored value (an ops/container
// escape-hatch and backward-compat), but they are never required: a fresh
// instance is configured entirely from the panel.
//
// resolveRuntime() is what the bind path (server.js) and the self-heal watchdog
// (index.js) consult. getApplied()/setApplied() record what the running listener
// actually bound with, so the panel can show a "restart to apply" reminder.

const db = require("@saltcorn/data/db");

const constants = require("../constants");
const { readKey, writeKey } = require("../configStore");


const rootSchema = () => String((db.connectObj && db.connectObj.default_schema) || "public").toLowerCase();


// Run fn in the ROOT/public tenant context so listener config is global to the
// instance regardless of which tenant's request/onLoad we are serving. A
// single-tenant (SQLite) deployment has only one context, so run directly.
const inRoot = (fn) => {
    if (db.is_it_multi_tenant && db.is_it_multi_tenant()) {
        return db.runWithTenant(rootSchema(), fn);
    }
    return fn();
};


const parseEnvPort = (raw) => {
    if (raw === undefined || raw === null || String(raw).trim() === "") {
        return null;
    }
    const n = parseInt(String(raw), 10);
    return Number.isFinite(n) ? n : null;
};


const isLoopbackHost = (host) => {
    const h = String(host || "").trim().toLowerCase();
    return h === "127.0.0.1" || h === "::1" || h === "localhost";
};


const validatePort = (n) => {
    return Number.isInteger(n) && n >= constants.LDAP_PORT_MIN && n <= constants.LDAP_PORT_MAX;
};


// The values stored in the public-site config (no env applied).
const getStoredConfig = async () => {
    return inRoot(async () => {
        const enabled = await readKey(constants.CFG_LDAP_ENABLED);
        const host    = await readKey(constants.CFG_LDAP_HOST);
        const port    = await readKey(constants.CFG_LDAP_PORT);
        return {
            enabled: enabled === true,
            host:    typeof host === "string" ? host : "",
            port:    Number.isFinite(port) ? port : null
        };
    });
};


const setStoredConfig = async (cfg) => {
    await inRoot(async () => {
        await writeKey(constants.CFG_LDAP_ENABLED, cfg.enabled === true);
        await writeKey(constants.CFG_LDAP_HOST, typeof cfg.host === "string" ? cfg.host.trim() : "");
        await writeKey(constants.CFG_LDAP_PORT, Number.isFinite(cfg.port) ? cfg.port : null);
    });
};


// Effective runtime settings: env overrides stored config PER SETTING (set =>
// wins), but env is never required. The listener runs iff enabled with a valid port.
const resolveRuntime = async () => {
    const stored  = await getStoredConfig();
    const envPort = parseEnvPort(process.env[constants.LDAP_PORT_ENV]);
    const envHost = (process.env[constants.LDAP_HOST_ENV] || "").trim();
    const port    = envPort !== null ? envPort : stored.port;
    const host    = envHost || stored.host || constants.LDAP_DEFAULT_HOST;
    // Presence of an env port preserves the legacy "env enables LDAP" behaviour.
    const enabled = envPort !== null ? true : stored.enabled;
    return {
        enabled:     enabled && Number.isFinite(port),
        host:        host,
        port:        Number.isFinite(port) ? port : null,
        portFromEnv: envPort !== null,
        hostFromEnv: !!envHost
    };
};


// What the running listener actually bound with (or { enabled: false } when off).
// The admin panel compares this against resolveRuntime() to decide whether a
// settings change still needs a restart to take effect.
const getApplied = async () => {
    const a = await inRoot(() => readKey(constants.CFG_LDAP_APPLIED));
    return a && typeof a === "object" ? a : null;
};


const setApplied = async (applied) => {
    const norm = {
        enabled: applied.enabled === true,
        host:    applied.enabled === true ? applied.host : null,
        port:    applied.enabled === true ? applied.port : null
    };
    // Avoid write churn (every onLoad/worker would otherwise rewrite it).
    const cur = await getApplied();
    if (cur && cur.enabled === norm.enabled && cur.host === norm.host && cur.port === norm.port) {
        return;
    }
    await inRoot(() => writeKey(constants.CFG_LDAP_APPLIED, norm));
};


module.exports = {
    getStoredConfig,
    setStoredConfig,
    resolveRuntime,
    getApplied,
    setApplied,
    isLoopbackHost,
    validatePort
};