const axios = require('axios');

function toMillis(completedTime) {
    if (!completedTime) return null;
    const raw = typeof completedTime === 'object' ? completedTime.value : completedTime;
    const ms = Number(raw);
    return Number.isFinite(ms) ? ms : null;
}

function getRelevantTicketTime(ticket) {
    return toMillis(ticket.completed_time)
        || toMillis(ticket.resolved_time)
        || toMillis(ticket.last_updated_time)
        || null;
}

async function fetchClosedTickets({ accessToken, state, tickets, technicians, statusSet, windowMinutes }) {
    if (!accessToken) return;

    try {
        const windowStart = Date.now() - windowMinutes * 60 * 1000;

        const listInfo = {
            list_info: {
                row_count: 200,
                sort_field: 'last_updated_time',
                sort_order: 'desc',
                fields_required: [
                    'display_id',
                    'subject',
                    'status',
                    'completed_time',
                    'resolved_time',
                    'last_updated_time',
                    'technician'
                ],
                search_criteria: [
                    {
                        field: 'last_updated_time',
                        condition: 'greater_than',
                        value: windowStart.toString()
                    }
                ]
            }
        };

        const response = await axios.get('https://ithelp.mainecc.edu/api/v3/requests', {
            params: { input_data: JSON.stringify(listInfo) },
            headers: {
                Authorization: `Zoho-oauthtoken ${accessToken}`,
                Accept: 'application/vnd.manageengine.sdp.v3+json'
            }
        });

        const found = response.data?.requests || [];

        for (const ticket of found) {
            const statusName = ticket.status?.name || '';
            const statusInternalName = ticket.status?.internal_name || '';
            const statusMatches = !statusSet.size
                || statusSet.has(statusName.toLowerCase())
                || statusSet.has(statusInternalName.toLowerCase());
            if (!statusMatches) continue;

            const closedAt = getRelevantTicketTime(ticket);
            if (!closedAt || closedAt <= windowStart) continue;

            const technician = ticket.technician ? ticket.technician.name : null;
            if (!technician) continue;
            if (technicians.length && !technicians.includes(technician)) continue;

            tickets.set(String(ticket.display_id), {
                id: ticket.display_id,
                subject: ticket.subject,
                technician,
                status: statusName || null,
                closedAt,
                closedDisplay: ticket.completed_time?.display_value
                    || ticket.resolved_time?.display_value
                    || ticket.last_updated_time?.display_value
                    || null
            });
        }

        const cutoff = Date.now() - 12 * 60 * 60 * 1000;
        for (const [key, ticket] of tickets) {
            if (ticket.closedAt < cutoff) tickets.delete(key);
        }

        state.lastCheck = Date.now();
        state.lastError = null;
    } catch (err) {
        const detail = err.response?.data;
        state.lastError = detail?.response_status?.messages?.[0]?.message
            || (typeof detail === 'string' ? detail : null)
            || err.message;
        state.lastCheck = Date.now();
        console.error('Error: ', detail || err.message);
    }
}

async function fetchUnassignedCount({ accessToken, state, statusSet, siteSet, groupSet }) {
    if (!accessToken) return;

    try {
        let count = 0;
        let startIndex = 1;
        const rowCount = 100;
        const maxPages = 50; // safety cap: 5000 unassigned tickets

        // The SDP instance ignores search_criteria arrays with more than one
        // condition, so only "technician is unassigned" is filtered server-side;
        // status/site/group are matched client-side per ticket below.
        for (let page = 0; page < maxPages; page++) {
            const listInfo = {
                list_info: {
                    row_count: rowCount,
                    start_index: startIndex,
                    search_criteria: {
                        field: 'technician',
                        condition: 'is',
                        value: null
                    },
                    fields_required: ['status', 'technician', 'group', 'requester']
                }
            };

            const response = await axios.get('https://ithelp.mainecc.edu/api/v3/requests', {
                params: { input_data: JSON.stringify(listInfo) },
                headers: {
                    Authorization: `Zoho-oauthtoken ${accessToken}`,
                    Accept: 'application/vnd.manageengine.sdp.v3+json'
                }
            });

            const found = response.data?.requests || [];

            for (const ticket of found) {
                if (ticket.technician) continue;

                const statusName = (ticket.status?.name || '').toLowerCase();
                const statusInternalName = (ticket.status?.internal_name || '').toLowerCase();
                const statusMatches = !statusSet.size
                    || statusSet.has(statusName)
                    || statusSet.has(statusInternalName);
                if (!statusMatches) continue;

                const groupName = (ticket.group?.name || '').toLowerCase();
                if (groupSet.size && !groupSet.has(groupName)) continue;

                const siteName = (ticket.requester?.site?.name || '').toLowerCase();
                if (siteSet.size && !siteSet.has(siteName)) continue;

                count++;
            }

            if (!response.data?.list_info?.has_more_rows || found.length === 0) break;
            startIndex += rowCount;
        }

        state.unassignedCount = count;
        state.unassignedError = null;
    } catch (err) {
        const detail = err.response?.data;
        state.unassignedError = detail?.response_status?.messages?.[0]?.message
            || (typeof detail === 'string' ? detail : null)
            || err.message;
        state.unassignedCount = null;
        console.error('Error fetching unassigned count: ', detail || err.message);
    }
}

module.exports = {
    fetchClosedTickets,
    fetchUnassignedCount
};