'use strict';

var C = module.exports;
var U = require('./utils.js');
var CSR = require('@root/csr');
var Enc = require('@root/encoding');
var Keypairs = require('@root/keypairs');

var pending = {};
var rawPending = {};

// What the abbreviations mean
//
// gnlkc => greenlock
// mconf => manager config
// db => greenlock store instance
// acme => instance of ACME.js
// chs => instances of challenges
// acc => account
// args => site / extra options

// Certificates
C._getOrOrder = function(gnlck, mconf, db, acme, chs, acc, args) {
    var email = args.subscriberEmail || mconf.subscriberEmail;

    var id = args.altnames
        .slice(0)
        .sort()
        .join(' ');
    if (pending[id]) {
        return pending[id];
    }

    pending[id] = C._rawGetOrOrder(
        gnlck,
        mconf,
        db,
        acme,
        chs,
        acc,
        email,
        args
    )
        .then(function(pems) {
            delete pending[id];
            return pems;
        })
        .catch(function(err) {
            delete pending[id];
            throw err;
        });

    return pending[id];
};

// Certificates
C._rawGetOrOrder = function(gnlck, mconf, db, acme, chs, acc, email, args) {
    return C._check(gnlck, mconf, db, args).then(function(pems) {
        // Nice and fresh? We're done!
        if (pems) {
            if (!C._isStale(gnlck, mconf, args, pems)) {
                // return existing unexpired (although potentially stale) certificates when available
                // there will be an additional .renewing property if the certs are being asynchronously renewed
                //pems._type = 'current';
                return pems;
            }
        }

        // We're either starting fresh or freshening up...
        var p = C._rawOrder(gnlck, mconf, db, acme, chs, acc, email, args);
        var evname = pems ? 'cert_renewal' : 'cert_issue';
        p.then(function(newPems) {
            // notify in the background
            var renewAt = C._renewWithStagger(gnlck, mconf, args, newPems);
            gnlck._notify(evname, {
                renewAt: renewAt,
                subject: args.subject,
                altnames: args.altnames
            });
            gnlck._notify('_cert_issue', {
                renewAt: renewAt,
                subject: args.subject,
                altnames: args.altnames,
                pems: newPems
            });
        }).catch(function(err) {
            if (!err.context) {
                err.context = evname;
            }
            err.subject = args.subject;
            err.altnames = args.altnames;
            gnlck._notify('error', err);
        });

        // No choice but to hang tight and wait for it
        if (
            !pems ||
            pems.renewAt < Date.now() - 24 * 60 * 60 * 1000 ||
            pems.expiresAt <= Date.now() + 24 * 60 * 60 * 1000
        ) {
            return p;
        }

        // Wait it out
        // TODO should we call this waitForRenewal?
        if (args.waitForRenewal) {
            return p;
        }

        // Let the certs renew in the background
        return pems;
    });
};

// we have another promise here because it the optional renewal
// may resolve in a different stack than the returned pems
C._rawOrder = function(gnlck, mconf, db, acme, chs, acc, email, args) {
    var id = args.altnames
        .slice(0)
        .sort()
        .join(' ');
    if (rawPending[id]) {
        return rawPending[id];
    }

    var keyType = args.serverKeyType || mconf.serverKeyType;
    var query = {
        subject: args.subject,
        certificate: args.certificate || {},
        directoryUrl:
            args.directoryUrl ||
            mconf.directoryUrl ||
            gnlck._defaults.directoryUrl
    };
    rawPending[id] = U._getOrCreateKeypair(db, args.subject, query, keyType)
        .then(function(kresult) {
            var serverKeypair = kresult.keypair;
            var domains = args.altnames.slice(0);

            return CSR.csr({
                jwk: serverKeypair.privateKeyJwk || serverKeypair.private,
                domains: domains,
                encoding: 'der'
            })
                .then(function(csrDer) {
                    // TODO let CSR support 'urlBase64' ?
                    return Enc.bufToUrlBase64(csrDer);
                })
                .then(function(csr) {
                    function notify(ev, opts) {
                        gnlck._notify(ev, opts);
                    }
                    var certReq = {
                        debug: args.debug || gnlck._defaults.debug,

                        challenges: chs,
                        account: acc, // only used if accounts.key.kid exists
                        accountKey:
                            acc.keypair.privateKeyJwk || acc.keypair.private,
                        keypair: acc.keypair, // TODO
                        csr: csr,
                        domains: domains, // because ACME.js v3 uses `domains` still, actually
                        onChallengeStatus: notify,
                        notify: notify // TODO

                        // TODO handle this in acme-v2
                        //subject: args.subject,
                        //altnames: args.altnames.slice(0),
                    };
                    return acme.certificates
                        .create(certReq)
                        .then(U._attachCertInfo);
                })
                .then(function(pems) {
                    if (kresult.exists) {
                        return pems;
                    }
                    query.keypair = serverKeypair;
                    return db.setKeypair(query, serverKeypair).then(function() {
                        return pems;
                    });
                });
        })
        .then(function(pems) {
            // TODO put this in the docs
            // { cert, chain, privkey, subject, altnames, issuedAt, expiresAt }
            // Note: the query has been updated
            query.pems = pems;
            return db.set(query);
        })
        .then(function() {
            return C._check(gnlck, mconf, db, args);
        })
        .then(function(bundle) {
            // TODO notify Manager
            delete rawPending[id];
            return bundle;
        })
        .catch(function(err) {
            // Todo notify manager
            delete rawPending[id];
            throw err;
        });

    return rawPending[id];
};

// returns pems, if they exist
C._check = function(gnlck, mconf, db, args) {
    var query = {
        subject: args.subject,
        // may contain certificate.id
        certificate: args.certificate,
        directoryUrl:
            args.directoryUrl ||
            mconf.directoryUrl ||
            gnlck._defaults.directoryUrl
    };
    return db.check(query).then(function(pems) {
        if (!pems) {
            return null;
        }

        pems = U._attachCertInfo(pems);

        // For eager management
        if (args.subject && !U._certHasDomain(pems, args.subject)) {
            // TODO report error, but continue the process as with no cert
            return null;
        }

        // For lazy SNI requests
        if (args.domain && !U._certHasDomain(pems, args.domain)) {
            // TODO report error, but continue the process as with no cert
            return null;
        }

        return U._getKeypair(db, args.subject, query)
            .then(function(keypair) {
                return Keypairs.export({
                    jwk: keypair.privateKeyJwk || keypair.private,
                    encoding: 'pem'
                }).then(function(pem) {
                    pems.privkey = pem;
                    return pems;
                });
            })
            .catch(function() {
                // TODO report error, but continue the process as with no cert
                return null;
            });
    });
};

// Certificates
C._isStale = function(gnlck, mconf, args, pems) {
    if (args.duplicate) {
        return true;
    }

    var renewAt = C._renewableAt(gnlck, mconf, args, pems);

    if (Date.now() >= renewAt) {
        return true;
    }

    return false;
};

C._renewWithStagger = function(gnlck, mconf, args, pems) {
    var renewOffset = C._renewOffset(gnlck, mconf, args, pems);
    var renewStagger;
    try {
        renewStagger = U._parseDuration(
            args.renewStagger || mconf.renewStagger || 0
        );
    } catch (e) {
        renewStagger = U._parseDuration(
            args.renewStagger || mconf.renewStagger
        );
    }

    // TODO check this beforehand
    if (!args.force && renewStagger / renewOffset >= 0.5) {
        renewStagger = renewOffset * 0.1;
    }

    if (renewOffset > 0) {
        // stagger forward, away from issued at
        return Math.round(
            pems.issuedAt + renewOffset + Math.random() * renewStagger
        );
    }

    // stagger backward, toward issued at
    return Math.round(
        pems.expiresAt + renewOffset - Math.random() * renewStagger
    );
};
C._renewOffset = function(gnlck, mconf, args /*, pems*/) {
    var renewOffset = U._parseDuration(
        args.renewOffset || mconf.renewOffset || 0
    );
    var week = 1000 * 60 * 60 * 24 * 6;
    if (!args.force && Math.abs(renewOffset) < week) {
        throw new Error(
            'developer error: `renewOffset` should always be at least a week, use `force` to not safety-check renewOffset'
        );
    }
    return renewOffset;
};
C._renewableAt = function(gnlck, mconf, args, pems) {
    if (args.renewAt) {
        return args.renewAt;
    }

    var renewOffset = C._renewOffset(gnlck, mconf, args, pems);

    if (renewOffset > 0) {
        return pems.issuedAt + renewOffset;
    }

    return pems.expiresAt + renewOffset;
};