/**
 * state.js — Shared reactive state store
 * Uses Vue.reactive() for global state management.
 * Replace with Pinia or API integration when backend is ready.
 */

function createStore() {
    const today = new Date();
    // Start on the most recent Monday
    const dayOfWeek = today.getDay();
    const mondayOffset = dayOfWeek === 0 ? -6 : 1 - dayOfWeek;
    const startDate = new Date(today);
    startDate.setDate(today.getDate() + mondayOffset);
    const startDateStr = startDate.toISOString().split('T')[0];

    const weekCount = 6;
    const totalDays = weekCount * 7;

    const schedule = generateSampleSchedule(AGENTS, startDate, totalDays);
    const exnetTargets = generateExnetTargets(startDate, totalDays);

    return Vue.reactive({
        // --- Data ---
        agents: [...AGENTS],
        shiftTypes: [...SHIFT_TYPES],
        exnetGroups: [...EXNET_GROUPS],
        departments: [...DEPARTMENTS],
        allSkills: [...SKILLS],
        activeUsers: [...ACTIVE_USERS],
        versionHistory: [...VERSION_HISTORY],

        // --- Schedule ---
        schedule: schedule,
        exnetTargets: exnetTargets,

        // --- View State ---
        startDate: startDateStr,
        weekCount: weekCount,
        todayStr: today.toISOString().split('T')[0],

        // --- Filters ---
        searchQuery: '',
        activeSkillFilters: [],
        activeDepartmentFilter: '',

        // --- Sidebar ---
        sidebarOpen: false,
        sidebarContext: null, // { agentId, dateStr }

        // --- Cell Editing ---
        editingCell: null, // { agentId, dateStr }

        // --- UI ---
        showVersionHistory: false,
    });
}

/* --- Computed helpers (plain functions operating on store) --- */

function getDateRange(store) {
    const dates = [];
    const start = new Date(store.startDate);
    const total = store.weekCount * 7;
    for (let i = 0; i < total; i++) {
        const d = new Date(start);
        d.setDate(start.getDate() + i);
        dates.push({
            date: d,
            dateStr: d.toISOString().split('T')[0],
            dayName: d.toLocaleDateString('en-US', { weekday: 'short' }),
            dayDate: d.toLocaleDateString('en-US', { day: 'numeric', month: 'short' }),
            dayOfWeek: d.getDay(),
            isToday: d.toISOString().split('T')[0] === store.todayStr,
            isWeekend: d.getDay() === 0 || d.getDay() === 6,
        });
    }
    return dates;
}

function getFilteredAgents(store) {
    let result = store.agents;

    if (store.searchQuery) {
        const q = store.searchQuery.toLowerCase();
        result = result.filter(a =>
            a.name.toLowerCase().includes(q) ||
            a.email.toLowerCase().includes(q) ||
            a.department.toLowerCase().includes(q)
        );
    }

    if (store.activeSkillFilters.length > 0) {
        result = result.filter(a =>
            store.activeSkillFilters.some(skill => a.skills.includes(skill))
        );
    }

    if (store.activeDepartmentFilter) {
        result = result.filter(a => a.department === store.activeDepartmentFilter);
    }

    return result;
}

function getCellData(store, agentId, dateStr) {
    const key = `${agentId}_${dateStr}`;
    return store.schedule[key] || { shifts: [], exnet: [], notes: '', locked: null, history: [] };
}

function updateCellShifts(store, agentId, dateStr, shifts, exnet) {
    const key = `${agentId}_${dateStr}`;
    if (!store.schedule[key]) {
        store.schedule[key] = { shifts: [], exnet: [], notes: '', locked: null, history: [] };
    }
    store.schedule[key].shifts = [...shifts];
    if (exnet !== undefined) {
        store.schedule[key].exnet = [...exnet];
    }
    // Add history entry
    store.schedule[key].history.unshift({
        user: 'You',
        action: shifts.length > 0 ? `Set ${shifts.join(', ')}` : 'Cleared shifts',
        timestamp: new Date().toISOString(),
    });
}

function updateCellNotes(store, agentId, dateStr, notes) {
    const key = `${agentId}_${dateStr}`;
    if (!store.schedule[key]) {
        store.schedule[key] = { shifts: [], exnet: [], notes: '', locked: null, history: [] };
    }
    store.schedule[key].notes = notes;
}

function openSidebar(store, agentId, dateStr) {
    store.sidebarContext = { agentId, dateStr };
    store.sidebarOpen = true;
}

function closeSidebar(store) {
    store.sidebarOpen = false;
    store.sidebarContext = null;
}