// Customer login has no relationship to the protected staff workspace.
var CustomerLogin = {
    create(options){
        const overlay=document.getElementById('customer-login');
        const form=document.getElementById('customer-login-form');
        const username=document.getElementById('customer-username');
        const password=document.getElementById('customer-password');
        const submit=document.getElementById('customer-submit');
        const cancel=document.getElementById('customer-cancel');
        const error=document.getElementById('customer-error');
        const account=document.getElementById('customer-account');
        let user, pending=null, opener=null, busy=false, version=0;
        overlay.hidden=true;
        function status(message){ error.textContent=message || ''; error.hidden=!message; }
        function render(){
            account.textContent=user ? user.name+' · '+options.text('customerLogout') : options.text('customerLogin');
            submit.textContent=options.text(busy ? 'customerSigningIn' : 'customerLogin');
            cancel.textContent=options.text('customerCancel');
            document.getElementById('customer-login-title').textContent=options.text('customerLogin');
            document.getElementById('customer-username-label').textContent=options.text('customerUsername');
            document.getElementById('customer-password-label').textContent=options.text('customerPassword');
            username.placeholder=options.text('customerUsernamePlaceholder');
            password.placeholder=options.text('customerPasswordPlaceholder');
        }
        function update(next){
            const previous=user;
            user=next;
            render();
            if(options.onChange && (previous === undefined || (previous && previous.id) !== (user && user.id))){
                options.onChange(user,previous);
            }
        }
        async function request(path, data){
            const controller=new AbortController();
            const timer=setTimeout(()=>controller.abort(),10000);
            try{
                const response=await options.fetch(path,{method:data === undefined ? 'GET' : 'POST',
                    headers:{'Content-Type':'application/json'},body:data === undefined ? undefined : JSON.stringify(data),signal:controller.signal});
                const result=await response.json();
                if(!response.ok || !result.ok){
                    const failure=new Error(result.error || result.e || options.text('customerLoginFailed'));
                    failure.publicMessage=true;throw failure;
                }
                return result;
            }finally{ clearTimeout(timer); }
        }
        async function refresh(){
            if(busy) return;
            const token=++version;
            try{
                const result=await request('/api/customer/session');
                if(token === version) update(result.authenticated && result.user ? result.user : null);
            }catch(error){} // Query endpoints still enforce login if status cannot refresh.
        }
        function close(){
            overlay.hidden=true;
            password.value='';
            pending=null;
            if(opener && opener.isConnected) opener.focus({preventScroll:true});
            opener=null;
        }
        function open(onSuccess){
            if(busy) return;
            pending=typeof onSuccess === 'function' ? onSuccess : null;
            opener=document.activeElement;
            status(''); password.value=''; overlay.hidden=false;
            if(options.onOpen) options.onOpen();
            render(); username.focus({preventScroll:true});
        }
        function setBusy(value){
            busy=value; submit.disabled=value; cancel.disabled=value; account.disabled=value;
            username.disabled=value; password.disabled=value; render();
        }
        form.addEventListener('submit',async function(event){
            event.preventDefault();
            if(busy) return;
            const token=++version;
            setBusy(true);status('');
            try{
                const result=await request('/api/customer/login',{username:username.value,password:password.value});
                if(token !== version) return;
                update(result.user);
                const resume=pending;close();
                if(resume) await resume();
            }catch(failure){
                if(token === version) status(failure.publicMessage ? failure.message : options.text('customerLoginFailed'));
            }finally{ if(token === version) setBusy(false); }
        });
        cancel.onclick=function(){ if(!busy) close(); };
        overlay.addEventListener('click',function(event){ if(event.target === overlay && !busy) close(); });
        overlay.addEventListener('keydown',function(event){
            if(event.key === 'Escape' && !busy){ event.preventDefault();close(); }
            if(event.key === 'Tab'){
                const controls=[username,password,submit,cancel].filter(control=>!control.disabled);
                if(!controls.length){ event.preventDefault();return; }
                const index=controls.indexOf(document.activeElement);
                const next=(index+(event.shiftKey ? -1 : 1)+controls.length)%controls.length;
                event.preventDefault();controls[next].focus({preventScroll:true});
            }
        });
        account.onclick=async function(){
            if(busy) return;
            if(!user){ open(); return; }
            const token=++version;setBusy(true);
            try{
                await request('/api/customer/logout',{});
                if(token === version) update(null);
            }catch(failure){ if(options.onError) options.onError(options.text('customerLogoutFailed')); }
            finally{ if(token === version) setBusy(false); }
        };
        window.addEventListener('focus',refresh);
        document.addEventListener('visibilitychange',function(){ if(!document.hidden) refresh(); });
        render();
        return {open:open,refresh:refresh,render:render,require:async function(resume, canContinue){
            if(busy) return;
            await refresh();
            if(canContinue && !canContinue(user)) return;
            if(user){ await resume(user); }else open(function(){ return resume(user); });
        },viewport:function(height,top){
            overlay.style.height=height || ''; overlay.style.top=top || '';
            overlay.style.bottom=height ? 'auto' : '';
        }};
    }
};