const http = require('http');
const db = require('./config/dbproc.js');

const ALLOWED_EMAILS = new Set([
    'david.rodriques@telin.net',
    'syam.thasya@telin.net',
]);

function buildHtml(approverName, title, priorName, idxjustification, remark, status) {
    const url = status === 'RETURNED'
        ? `https://e-portal.telkomcel.tl/app/ext/eproc/justifikasi/${idxjustification}/edit`
        : `https://e-portal.telkomcel.tl/app/ext/eproc/circulation/${idxjustification}`;
    const statusLabel = status || 'READY FOR APPROVAL';
    const notesLine = remark ? `  <li><strong>Notes:</strong> ${remark}</li>\n` : '';
    return `<p>Dear ${approverName},</p>

<p>A new workflow task requires your review and approval. Please find the details regarding this justification below:</p>

<ul>
  <li><strong>Justification:</strong> ${title}</li>
  <li><strong>Task Type:</strong> OPEN</li>
  <li><strong>Status:</strong> ${statusLabel}</li>
${notesLine}  <li><strong>Sent By:</strong> ${priorName}</li>
</ul>

<p><strong>Action Required:</strong><br>
Please access the document and complete the approval via the E-Procurement Portal using the link below:<br>
<a href="${url}">${url}</a></p>

<p>If you have any questions or require further clarification, please do not hesitate to contact the Procurement Division.</p>

<p>Thank you for your attention and cooperation.</p>

<p>Best regards,<br>
Procurement Division<br>
Finance Business Partner Unit</p>`;
}

function logEmail(trxId, toEmail, subject, html, fromEmail, status, requestPayload, responseMessage) {
    const qry = `
        INSERT INTO email_logs (trx_id, to_email, subject, body, from_email, is_attachment, status, request_payload, response_message, created_at)
        VALUES (?, ?, ?, ?, ?, 0, ?, ?, ?, NOW())
    `;
    db.query(qry, [trxId, toEmail, subject, html, fromEmail, status, requestPayload, responseMessage], function(err) {
        if (err) console.error('[email-notif] logEmail failed:', err.message);
    });
}

function postEmail(toEmail, approverName, title, priorName, idxjustification, remark, status) {
    if (!ALLOWED_EMAILS.has(toEmail)) {
        console.log('[email-notif] skipped (not in allowed list):', toEmail);
        return;
    }

    const subject = status === 'RETURNED'
        ? `[Returned] Justification for ${title}`
        : `[Approval Required] Justification for ${title}`;
    const html = buildHtml(approverName, title, priorName, idxjustification, remark, status);
    const payload = JSON.stringify({
        to: [toEmail],
        cc: [],
        bcc: [],
        subject,
        html
    });

    const req = http.request({
        hostname: 'localhost',
        port: 7004,
        path: '/api/email/send-telkomcel',
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'Content-Length': Buffer.byteLength(payload)
        }
    }, (res) => {
        let body = '';
        res.on('data', (chunk) => { body += chunk; });
        res.on('end', () => {
            let trxId = '';
            let responseMessage = body;
            try {
                const parsed = JSON.parse(body);
                trxId = parsed?.data?.trx_id || '';
                responseMessage = JSON.stringify(parsed);
            } catch (_) {}

            const logStatus = res.statusCode >= 200 && res.statusCode < 300 ? 'success' : 'failed';
            console.log('[email-notif] sent, status:', res.statusCode, '| trxId:', trxId, '| to:', toEmail);
            logEmail(trxId, toEmail, subject, html, '', logStatus, payload, responseMessage);
        });
    });

    req.on('error', (err) => {
        console.error('[email-notif] failed:', err.message);
        logEmail('', toEmail, subject, html, '', 'failed', payload, err.message);
    });

    req.write(payload);
    req.end();
}

/**
 * Notify first approver when justification is submitted.
 */
function notifyOnSubmit(idxjustification) {
    const qryJustification = `
        select j.title, j.remark, e.fullname as creator_name
        from tbl_justification j
        join dbssotcel.tbl_employee e on e.nik = j.iby
        where j._idx = '${idxjustification}' limit 1
    `;
    db.query(qryJustification, [], function(err, rows) {
        if (err || rows.length === 0) {
            console.error('[email-notif] notifyOnSubmit: failed to get justification data', err);
            return;
        }
        const title = rows[0].title;
        const remark = rows[0].remark || '';
        const creatorName = rows[0].creator_name;

        const qryApprover = `
            select t.nik, e.fullname, e.email
            from tbl_justificationttd t
            join dbssotcel.tbl_employee e on e.nik = t.nik
            where t.idxjustification = '${idxjustification}' and t.issigned = 0 and t.isdeleted = 0
            order by t._idx asc limit 1
        `;
        db.query(qryApprover, [], function(err2, rows2) {
            if (err2 || rows2.length === 0) {
                console.error('[email-notif] notifyOnSubmit: no approver found', err2);
                return;
            }
            postEmail(rows2[0].email, rows2[0].fullname, title, creatorName, idxjustification, remark);
        });
    });
}

/**
 * Notify next approver after someone signs.
 */
function notifyOnSigned(idxjustification, signerNik) {
    const qryTitle = `select title, remark from tbl_justification where _idx = '${idxjustification}' limit 1`;
    db.query(qryTitle, [], function(err, rows) {
        if (err || rows.length === 0) {
            console.error('[email-notif] notifyOnSigned: failed to get justification title', err);
            return;
        }
        const title = rows[0].title;
        const remark = rows[0].remark || '';

        const qrySigner = `select fullname from dbssotcel.tbl_employee where nik = '${signerNik}' limit 1`;
        db.query(qrySigner, [], function(err2, rows2) {
            if (err2 || rows2.length === 0) {
                console.error('[email-notif] notifyOnSigned: failed to get signer name', err2);
                return;
            }
            const signerName = rows2[0].fullname;

            const qryNext = `
                select t.nik, e.fullname, e.email
                from tbl_justificationttd t
                join dbssotcel.tbl_employee e on e.nik = t.nik
                where t.idxjustification = '${idxjustification}' and t.issigned = 0 and t.isdeleted = 0
                order by t._idx asc limit 1
            `;
            db.query(qryNext, [], function(err3, rows3) {
                if (err3 || rows3.length === 0) {
                    console.log('[email-notif] notifyOnSigned: no more approvers to notify');
                    return;
                }
                postEmail(rows3[0].email, rows3[0].fullname, title, signerName, idxjustification, remark);
            });
        });
    });
}

/**
 * Notify creator when justification is returned.
 */
function notifyOnReturn(idxjustification, returnerNik) {
    const qryJustification = `
        select j.title, j.remark, e.fullname as creator_name, e.email as creator_email
        from tbl_justification j
        join dbssotcel.tbl_employee e on e.nik = j.iby
        where j._idx = '${idxjustification}' limit 1
    `;
    db.query(qryJustification, [], function(err, rows) {
        if (err || rows.length === 0) {
            console.error('[email-notif] notifyOnReturn: failed to get justification data', err);
            return;
        }
        const title = rows[0].title;
        const remark = rows[0].remark || '';
        const creatorName = rows[0].creator_name;
        const creatorEmail = rows[0].creator_email;

        const qryReturner = `select fullname from dbssotcel.tbl_employee where nik = '${returnerNik}' limit 1`;
        db.query(qryReturner, [], function(err2, rows2) {
            if (err2 || rows2.length === 0) {
                console.error('[email-notif] notifyOnReturn: failed to get returner name', err2);
                return;
            }
            const returnerName = rows2[0].fullname;
            postEmail(creatorEmail, creatorName, title, returnerName, idxjustification, remark, 'RETURNED');
        });
    });
}

module.exports = { notifyOnSubmit, notifyOnSigned, notifyOnReturn };