const express = require('express');
const bodyParser = require('body-parser');
const session = require('express-session');
const QRCode=require('qrcode');
const crypto=require('crypto');
const path=require('path');

const app = express();
app.set('view engine','ejs');
app.use(express.json());
app.use(express.static('public'));
const PORT = 3000;
const PWSalt   ="!SaltyMagic7283715374";
const EmailSalt="!SaltyMagic3562196239";
const QRSalt   ="!SaltyMagic5392370662";

//
// ToDo, Actions:
//   + Login with Password
//   + Login with Token
//   + Email Link
//   + Display Many Tickets (User)
//   + Display One Ticket (User)
//   + Camp Editor
//   + Use Ticket
//   + Claim Any Tickets
//   + Purge Revoked Function (Admin)
//   + Issue Tickets from Camp Admin Page
//     See how much each camp/ticket has paid (Admin)
//     Send email when new tickets are issued/offered
//
// ToDo, Later
//   + Use a templating engine
//   + Store password hashed and salted
//     Make all HTML look nice
//     Logging and Replay system
//     Stripe Integration
//

//
// Login workflow:
//   There is always an implicit magic link that allows anyone to log in with their email address and hash(GlobalSalt+PerUserSalty+Email), except if the user sets a password for himself.
//   We store a per-user salt, initially the empty string, in case we need to invalidate particular users' magic links.
//

//
// Commands
//   ISSUE campname email
//   USE ticket
//   STATUS ticket i/u/r
//   CLAIM ticket email
//

function hashEmail(email) {
    const hash0=crypto.createHash('sha256');
    const usersalt=email in users ? (linksalt in users[email] ? users[email].linksalt : "") : "";
    const hash1=hash0.update(email+EmailSalt+usersalt);
    const hash=hash1.digest("base64");
    return(hash);
}

function hashPW(pw) {
    const hash0=crypto.createHash('sha256');
    const hash1=hash0.update(pw+PWSalt);
    const hash=hash1.digest("base64");
    return(hash);
}

function hashQR(t,ownername) {
    const hash0=crypto.createHash('sha256');
    const hash1=hash0.update(t+QRSalt+ownername);
    const hash=hash1.digest("base64").slice(0,6);
    return(hash);
}

//
// In-memory data structures
//
// There are two ways to log in: with a username/password or with a token. 
//
const users = { "teppy@egenesis.com"    : { password: hashPW("x6321872X.1"),      superuser:true,  linksalt:""  },
	        "fallsonfire@gmail.com" : { password: hashPW("indiantreeonfire"), superuser:false, linksalt:"boobsarefun" }
	      };

// Status can be "i"=issued, "u"=used, "r"=revoked"
const tickets = { "habitat-1" : { owner: "teppyx@egenesis.com"  , offered: "", paid: 0.00, status:"i" },
		  "habitat-2" : { owner: "teppyx@egenesis.com"  , offered: "", paid: 0.00, status:"u" },
		  "habitat-3" : { owner: "ginachen94@gmail.com", offered: "teppyx@egenesis.com", paid: 0.00, status:"i" },
		  "habitat-4" : { owner: "teppyx@egenesis.com"  , offered: "noahstern00@gmail.com", paid: 0.00, status:"i" },
          	  "habitat-5" : { owner: "teppyx@egenesis.com"  , offered: "", paid: 0.00, status:"r" },
		  "habitat-6" : { owner: "teppyx@egenesis.com"  , offered: "", paid: 0.00, status:"i" },
		};

const camps = { "habitat": { leader: "teppy@egenesis.com", lastid:6 } };

// Middleware setup
app.use(bodyParser.urlencoded({ extended: true }));
app.use(session({
  secret: 'supersecretkey',
  resave: false,
  saveUninitialized: false,
}));

// Middleware to protect routes
function requireLogin(req, res, next) {
    if (req.session.username) return next();
    req.session.returnTo=req.originalUrl;
    return res.redirect('/login');
    }

function requireSuperUser(req,res,next) {
    if (req.session.superuser) return next();
    req.session.returnTo=req.originalUrl;
    return res.redirect('/login');
    }


app.get('/styles.css', (req, res) => {
    res.setHeader('Content-Type', 'text/css');
    res.sendFile(path.join(__dirname, 'public', 'styles.css'));
    });

function generateSecureToken(length = 8) {
    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    let token = '';
    const array = new Uint8Array(length);
    crypto.getRandomValues(array);
    for (let i = 0; i < length; i++) {
        token += characters.charAt(array[i] % characters.length);
    }
    return token;
}


const postmark = require('postmark');
const client = new postmark.ServerClient('f45bcb9f-6556-4420-9e21-05d16739b5e8');

app.get('/emaillink',(req,res) => {
    res.send(`
      <h1>Email me a login link</h1>
      <form method="POST" action="/emaillink">
        <label>Email Address: <input name="email"></label>
        <button type="submit">Submit</button>`
            )
    });


app.get('/camps',requireSuperUser, (req,res) => {
    const camplist={};
    for (const c in camps) {
        camplist[c]={ leader:camps[c].leader, issued:0, claimed:0, used:0 };
        }
    for (const t in tickets) {
        const parts=t.split("-");
        const campname=parts[0]; 
        const ticketnum=Number(parts[1]);
        if (tickets[t].status!="r") {
            camplist[campname].issued+=1;
            if (tickets[t].owner!="")    camplist[campname].claimed+=1;
            if (tickets[t].status=="u")  camplist[campname].used+=1;
            }
        }
    return res.render("camps",{ username:req.session.username, superuser:req.session.superuser, camps:camplist });
    })
    
app.post("/camps",requireSuperUser,(req,res) => {
    console.log("New camp: ");
    const campname=req.body.campname;
    const leader=req.body.leader;
    const qty=Number(req.body.qty);
    camps[campname]??={ leader:leader, lastid:0 };
    for (let i=0; i<qty; i++) {
        camps[campname].lastid+=1; // LOG  
        tickets[campname+'-'+camps[campname].lastid]={ owner: "", offered: leader, status:"i" }; // LOG
        }
    return res.redirect("/camps");
    })


app.get('/camplead', requireLogin, (req,res) => {
    let username=req.session.username;
    const edit={ username:username, superuser:req.session.superuser, tickets: {} };
    for (const t in tickets) if (tickets[t].owner==username && tickets[t].status!='r') {
        edit.tickets[t]={};
        edit.tickets[t].owner=tickets[t].owner;
        edit.tickets[t].offered=tickets[t].offered;
        edit.tickets[t].used=tickets[t].status=='u';
        }
    return res.render("camplead",edit);
    })


app.get('/editcamp', requireSuperUser, (req,res) => {
    let campname=req.query.campname;
    const edit={ username:req.session.username, superuser:req.session.superuser, campname:campname, leader:camps[campname].leader, tickets: {} };
    for (const t in tickets) {
        const parts=t.split("-");
        const cname=parts[0];
        const tnum=Number(parts[1]);
        if (cname==campname) {
            edit.tickets[t]={};
            edit.tickets[t].owner=tickets[t].owner;
            edit.tickets[t].offered=tickets[t].offered;
            edit.tickets[t].status=tickets[t].status;
            }
        }
    return res.render("editcamp",edit);
    })

app.post('/moretickets', requireSuperUser, (req,res) => {
    const qty=Number(req.body.qty);
    const campname=req.body.campname;
    console.log("More tickets! ",campname in camps,qty);
    if (campname in camps) for (let i=0; i<qty; i++) {
        camps[campname].lastid++;
        tickets[campname+'-'+camps[campname].lastid]={ owner:"", offered:camps[campname].leader, paid:0, status:"i" };
        }
    const referer = req.get('Referer');
    if (referer) return res.redirect(referer);
    else         return res.redirect('/');
    });

app.get('/manytickets', requireLogin, (req,res) => {
    let username=req.session.username;
    const edit={ username:req.session.username, superuser:req.session.superuser, tickets: {} };
    for (const t in tickets) if (tickets[t].owner==username && tickets[t].status=="i") {
        edit.tickets[t]={};
        edit.tickets[t].offered=tickets[t].offered;
        }
    return res.render("manytickets",edit);
    })


app.get('/mytickets',requireLogin, async (req,res)=> {
    console.log("In mytickets req.session is ",req.session);
    let username=req.session.username;
    let claimed=0;
    let owned=0;
    let theticket="";
    const edit={ username:req.session.username, superuser:req.session.superuser, tickets: {} };
    for (const t in tickets) {
        if (tickets[t].status=="i" && tickets[t].offered==username) { claimed++; tickets[t].owner=username; tickets[t].offered=""; } // LOG
        if (tickets[t].status=="i" && tickets[t].owner==username) {
            owned++;
            if (owned==1) theticket=t; else theticket="";
            edit.tickets[t]={};
            edit.tickets[t].owner=tickets[t].owner;
            edit.tickets[t].offered=tickets[t].offered;
            }
        }
    if      (owned==0) return res.render("message",{ username:username, superuser:req.session.superuser, message:"You have no unused tickets" });
    else if (owned==1) {
        const hash0=crypto.createHash('sha256');
        const hash1=hash0.update(theticket+QRSalt);
        const hash=hash1.digest("base64").slice(0,6);
        const dataURL=await QRCode.toDataURL('localhost:3000/useticket?t='+theticket+'&h='+hashQR(theticket,username));
        return res.render("oneticket",{ username:username, superuser:req.session.superuser, ticket:theticket, offered:tickets[theticket].offered, qrcode:dataURL });
        }
    else               return res.render("manytickets",edit);
});

app.post('/mytickets',requireLogin, async (req,res)=> {
    let username=req.session.username;
    let theticket=req.body.ticket;
    let offered=req.body.offered;
    if (tickets[theticket].owner==username && tickets[theticket].status=="i") {
        tickets[theticket].offered=offered; // LOG
        }
    const hash0=crypto.createHash('sha256');
    const hash1=hash0.update(theticket+QRSalt);
    const hash=hash1.digest("base64").slice(0,6);
    const dataURL=await QRCode.toDataURL('localhost:3000/useticket?t='+theticket+'&h='+hashQR(theticket,username));
    return res.render("oneticket", { username:username, superuser:req.session.superuser, ticket:theticket, offered:tickets[theticket].offered, qrcode:dataURL });
});



app.post("/changestatus", requireSuperUser, (req,res) => {
    const ticket=req.body.ticket;
    console.log("Changestatus ",ticket);
    tickets[ticket].status=req.body.status; // LOG
    res.json({ message: 'Status received', status: req.body.status });
    })

app.post("/updateoffered", requireLogin, (req,res) => {
    console.log("UpdateOffered being rubn");
    const ticket=req.body.ticket;
    const offered=req.body.offered;
    if      (tickets[ticket].owner!=req.session.username) res.status(500).send("Ticket "+ticket+" owned by someone else");
    else if (tickets[ticket].status=="u")                 res.status(500).send("Ticket "+ticket+" has already been used");
    else if (tickets[ticket].status=="r")                 res.status(500).send("Ticket "+ticket+" was revoked");
    else {
        tickets[ticket].offered=offered; // LOG
        res.json({ message: 'Updated owner of '+ticket+' to '+offered });
        }
    })


app.post("/updateticketsu", requireSuperUser, (req,res) => {
    const ticket=req.body.ticket;
    const owner=req.body.owner;
    const offered=req.body.offered;
    tickets[ticket].owner=req.body.owner; // LOG
    tickets[ticket].offered=req.body.offered; // LOG
    res.json({ message: 'Updated '+ticket });
    })


app.get("/useticket",(req,res) => {
    let ticket=req.t;
    let hash=req.h;
    if (hashQR(ticket,req.session.username)!=hash) res.status(500).send("Ticket "+ticket+" was transferred to "+tickets[ticket].username);
    else if (tickets[ticket].status!="i") res.status(500).send("Ticket "+ticket+" has already been used.");
    else {
        tickets[ticket].status="u"; // LOG
        res.send("<h1>Welcome, "+tickets[ticket].owner+" to Falls on Fire! Ticket "+ticket+" has now been used.</h1>");
        }
})

    

function knownEmail(email) {
    if (users[email]) return true;
    for (const key in tickets)
        if (tickets[key].owner==email || tickets[key].offered==email) return true;
    return false;
}

app.post('emaillink',(req,res) => {
    if (!knownUser(req.email)) return res.send("Unknown User");
    const tok=createtoken(email);
    client.sendEmail({ From: 'tickets@fallsonfire.net',
                       To: 'teppy@egenesis.com',
		       Subject: 'Falls on Fire Tickets, Login Link',
		       TextBody: 'Your Login Link: http://www.fallonfire.net/longinlink?token='+tok,
		       HtmlBody: '<p>Your Login Link: </p>',
		     }).then(() => {
			 console.log('Email sent');
			 res.send("<h1>Email sent</h1>");
		     }).catch((error) => {
			 console.error('Error sending email:', error);
			 res.send("<h1>Email failed</h1>");
		     });
    res.send("Email link sent");
})
 

app.get('/testemail',
	(req,res) => {
	    client.sendEmail({ From: 'tickets@fallsonfire.net',
			       To: 'teppy@egenesis.com',
			       Subject: 'Email from Ticketing System',
			       TextBody: 'This is a test email.',
			       HtmlBody: '<p>This is a test email.</p>',
			     }).then(() => {
				 console.log('Email sent');
				 res.send("<h1>Email sent</h1>");
			     }).catch((error) => {
				 console.error('Error sending email:', error);
				 res.send("<h1>Email failed</h1>");
			     })});




// Routes
app.get('/', (req, res) => {
    if (req.session.username) return res.redirect("/mytickets");
    return res.render("login", { superuser:false });
});

app.get('/login',(req,res) => {
    return res.render("login",{ superuser:false });
});

app.get('/signup', (req, res) => {
  res.send(`
    <h1>Sign Up</h1>
    <form method="POST" action="/signup">
      <label>Username: <input type="text" name="username" required></label><br>
      <label>Password: <input type="password" name="password" required></label><br>
      <button type="submit">Sign Up</button>
    </form>
    <a href="/login">Log In</a>
  `);
});




app.post('/signup', (req, res) => {
  const { username, password } = req.body;
  if (users[username]) {
    return res.send('User already exists. <a href="/signup">Try again</a>');
  }
    users[username] = { password: hashPW(password) };
    console.log("Created new account:",username);
  res.redirect('/login');
});

app.get('/changepassword', (req, res) => {
  res.send(`
    <h1>Change Password</h1>
    <form method="POST" action="/changepassword">
      <label>Password: <input type="password" name="password1" required></label><br>
      <label>Again: <input type="password" name="password2" required></label><br>
      <button type="submit">Sign Up</button>
    </form>
    <a href="/">Home</a>
  `);
});

app.post('/changepassword', (req, res) => {
    const { password1, password2 } = req.body;
    if (!req.session.username) {
	return res.send('You are not logged in<a href="/">Back</a>');
        }
    if (password1!=password2) {
        return res.send('Passwords do not match<a href="/">Back</a>');
        }
  users[req.session.username].password=hashPW(password1);
  res.redirect('/');
});


app.post('/login', (req, res) => {
    const { username, password, superuser } = req.body;
    if (users[username] && users[username].password === hashPW(password)) {
        req.session.username = username;
        req.session.superuser = users[username].superuser;
        console.log("In post /login",req.session);
        const redir=req.session.returnTo;
        delete req.session.returnTo;
        return res.redirect(redir || "/mytickets");
  }
  res.send('Invalid username or password. <a href="/login">Try again</a>');
});

app.get('/logout', (req, res) => {
  req.session.destroy(() => {
    res.redirect('/');
  });
});

app.post('/qrcode',requireLogin,async (req,res) => {
    const username=req.session.username;
    const ticket=req.body.ticket;
    if (tickets[ticket].owner!=username) return res.status(500).send("Only a ticket owner can generate a QR code");
    const URL=await QRCode.toDataURL('localhost:3000/useticket?t='+ticket+'&h='+hashQR(ticket,username));
    return res.send({ owner:tickets[ticket].owner, qrcode: URL });
    })

app.post('/qrcodesu',requireSuperUser,async (req,res) => {
    const username=req.session.username;
    const ticket=req.body.ticket;
    const URL=await QRCode.toDataURL('localhost:3000/useticket?t='+ticket+'&h='+hashQR(ticket,username));
    return res.send({ owner:tickets[ticket].owner, qrcode: URL });
    })

app.get('/settings',requireSuperUser, (req,res) => {
    res.render('settings',{ username:req.session.username, superuser:req.session.superuser, message: "" })
    });

app.post('/wipedb',requireSuperUser, (req,res) => {
    for (const key in users  ) delete users[key];
    for (const key in tickets) delete tickets[key];
    for (const key in camps  ) delete camps[key];
    res.render('settings',{ username:req.session.username, superuser:req.session.superuser, message: "Wiped the database, but not the logfile." })
    });

app.post('/purge',requireSuperUser, (req,res) => {
    let count=0;
    for (const t in tickets) if (tickets[t].status=='r') { count++; delete tickets[t]; }
    res.render('message',{ username:req.session.username, superuser:req.session.superuser, message: "Purged "+count+" revoked tickets" })
    });


// Start the server
app.listen(PORT, () => {
  console.log(`Server is running at http://localhost:${PORT}`);
});