"use client"

import type React from "react"

import { Button } from "@/components/ui/button"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"

import { Checkbox } from "@/components/ui/checkbox"
import { RadioGroup, RadioGroupItem } from "@/components/ui/radio-group"
import Link from "next/link"
import { useEffect, useState } from "react"
import {
  EVENT_SHORT,
  EVENT_FULL_NAME,
  EVENT_DATES,
  EVENT_LOCATION,
  PRICING_TIERS,
  PROCESSING_FEE_PERCENT,
  ACCOMMODATION_VENUES,
  ACCOMMODATION_MAP,
  ACCOMMODATION_NIGHTS,
  LINKS,
} from "@/lib/event.config"

// Determine current tier client-side
function getClientTier() {
  const now = new Date().toISOString().slice(0, 10)
  return PRICING_TIERS.find((t) => now < t.cutoff) ?? PRICING_TIERS[PRICING_TIERS.length - 1]
}

export default function RegisterPage() {
  const [step, setStep] = useState<"form" | "payment">("form")
  const [isSubmitting, setIsSubmitting] = useState(false)
  const [includeAccommodation, setIncludeAccommodation] = useState(true)

  const [selectedVenueKey, setSelectedVenueKey] = useState(ACCOMMODATION_VENUES[0]?.key || "")
  const [accommodationType, setAccommodationType] = useState(
    ACCOMMODATION_VENUES[0]?.options[0]?.id || ""
  )
  const [formData, setFormData] = useState({
    name: "",
    email: "",
  })
  const [availability, setAvailability] = useState<Record<string, boolean>>({})

  // Fetch accommodation availability on mount
  useEffect(() => {
    fetch("/api/accommodation-availability")
      .then((res) => (res.ok ? res.json() : null))
      .then((data) => {
        if (data && typeof data === "object" && !data.error) {
          setAvailability(data)
          // If current selection is sold out, clear it
          if (accommodationType && data[accommodationType] === false) {
            const firstAvailable = ACCOMMODATION_VENUES.flatMap((v) => v.options)
              .find((o) => data[o.id] !== false)
            if (firstAvailable) {
              setAccommodationType(firstAvailable.id)
              const venue = ACCOMMODATION_VENUES.find((v) => v.options.some((o) => o.id === firstAvailable.id))
              if (venue) setSelectedVenueKey(venue.key)
            }
          }
        }
      })
      .catch(() => {}) // Fail silently — all options remain enabled
  }, []) // eslint-disable-line react-hooks/exhaustive-deps

  const tier = getClientTier()
  const baseTicketPrice = tier.price

  const accommodationPrice = ACCOMMODATION_MAP[accommodationType]?.price ?? 0
  const subtotalPrice =
    baseTicketPrice +
    (includeAccommodation ? accommodationPrice : 0)
  const processingFee = Math.round(subtotalPrice * PROCESSING_FEE_PERCENT * 100) / 100
  const totalPrice = subtotalPrice + processingFee

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    // Validate required fields
    if (
      !formData.name ||
      !formData.email
    ) {
      alert("Please fill in all required fields")
      return
    }

    setIsSubmitting(true)

    try {
      // Submit registration to Google Sheet first
      const response = await fetch("/api/register", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          name: formData.name,
          email: formData.email,
        }),
      })

      if (!response.ok) {
        throw new Error("Failed to record registration")
      }

      // Proceed to payment step
      setStep("payment")
    } catch (error) {
      console.error("Registration error:", error)
      alert("There was an error recording your registration. Please try again.")
    } finally {
      setIsSubmitting(false)
    }
  }

  // Pricing summary line
  const pricingSummary = PRICING_TIERS.map(
    (t) => `€${t.price} ${t.label}${t === tier ? " (current)" : ""}`
  ).join(" · ")

  if (step === "payment") {
    return (
      <div className="min-h-screen bg-background">
        {/* Header */}
        <header className="border-b">
          <div className="container mx-auto px-4 py-4">
            <Link href={LINKS.website} className="text-2xl font-bold text-primary">
              {EVENT_SHORT}
            </Link>
          </div>
        </header>

        <main className="container mx-auto px-4 py-12 max-w-5xl">
          <div className="text-center mb-12">
            <h1 className="text-4xl md:text-5xl font-bold mb-4">Complete Your Registration</h1>
            <p className="text-xl text-muted-foreground">Choose your payment method</p>
          </div>

          <Card className="mb-8 border-primary/40">
            <CardContent className="pt-6">
              <div className="space-y-4">
                {/* Ticket */}
                <div className="flex items-start justify-between py-4 border-b border-border">
                  <div>
                    <div className="font-medium">{EVENT_SHORT} Ticket</div>
                    <div className="text-sm text-muted-foreground">
                      {pricingSummary}
                    </div>
                  </div>
                  <span className="text-lg font-semibold whitespace-nowrap ml-4">€{baseTicketPrice.toFixed(2)}</span>
                </div>

                {/* Accommodation */}
                <div className="py-4 border-b border-border">
                  <div className="flex items-start gap-3">
                    <Checkbox
                      id="include-accommodation"
                      checked={includeAccommodation}
                      onCheckedChange={(checked) => setIncludeAccommodation(checked as boolean)}
                      className="mt-1"
                    />
                    <div className="flex-1">
                      <div className="flex justify-between items-start">
                        <Label htmlFor="include-accommodation" className="font-medium cursor-pointer">
                          Accommodation ({ACCOMMODATION_NIGHTS} nights)
                        </Label>
                        {includeAccommodation && (
                          <span className="text-lg font-semibold whitespace-nowrap ml-4">€{accommodationPrice.toFixed(2)}</span>
                        )}
                      </div>
                      {includeAccommodation ? (
                        <div className="mt-3">
                          <RadioGroup
                            value={accommodationType}
                            onValueChange={(value: string) => {
                              setAccommodationType(value)
                              const venue = ACCOMMODATION_VENUES.find((v) =>
                                v.options.some((o) => o.id === value)
                              )
                              if (venue) setSelectedVenueKey(venue.key)
                            }}
                            className="space-y-4"
                          >
                            {ACCOMMODATION_VENUES.map((venue) => (
                              <div key={venue.key}>
                                <p className="font-medium text-sm mb-1">{venue.name}</p>
                                <p className="text-xs text-muted-foreground mb-2">
                                  {venue.description}
                                </p>
                                <div className="pl-4 border-l-2 border-primary/20 space-y-2">
                                  {venue.options.map((opt) => {
                                    const soldOut = availability[opt.id] === false
                                    return (
                                    <div key={opt.id} className={`flex items-center space-x-2 ${soldOut ? "opacity-50" : ""}`}>
                                      <RadioGroupItem value={opt.id} id={opt.id} disabled={soldOut} />
                                      <Label htmlFor={opt.id} className={`font-normal text-sm ${soldOut ? "cursor-not-allowed" : "cursor-pointer"}`}>
                                        {opt.label} — {soldOut ? (
                                          <span className="text-destructive font-medium">Sold Out</span>
                                        ) : (
                                          <>€{opt.price.toFixed(2)} (€{opt.nightlyRate}/night)</>
                                        )}
                                      </Label>
                                    </div>
                                    )
                                  })}
                                </div>
                              </div>
                            ))}
                          </RadioGroup>
                        </div>
                      ) : (
                        <p className="text-sm text-muted-foreground mt-1">
                          I&apos;ll arrange my own accommodation
                        </p>
                      )}
                    </div>
                  </div>
                </div>

                <p className="text-xs text-muted-foreground bg-muted/50 rounded-lg p-3">
                  Additional Note: We&apos;ll follow up closer to the event to confirm room assignments and dietary preferences.
                </p>

                {/* Processing fee */}
                <div className="flex items-start justify-between py-3">
                  <div>
                    <div className="text-sm text-muted-foreground">Payment processing fee ({(PROCESSING_FEE_PERCENT * 100).toFixed(0)}%)</div>
                  </div>
                  <span className="text-sm text-muted-foreground whitespace-nowrap ml-4">€{processingFee.toFixed(2)}</span>
                </div>

                {/* Total */}
                <div className="flex justify-between items-center py-4 bg-primary/10 -mx-6 px-6 mt-4">
                  <div>
                    <div className="font-bold text-lg">Total Amount</div>
                    <div className="text-sm text-muted-foreground">
                      Ticket{includeAccommodation ? " + accommodation" : ""}
                    </div>
                  </div>
                  <span className="text-2xl font-bold text-primary">€{totalPrice.toFixed(2)}</span>
                </div>
              </div>
            </CardContent>
          </Card>

          {/* Payment Methods */}
          <div className="space-y-6">
            <Card>
              <CardHeader>
                <CardTitle>Payment Options</CardTitle>
                <CardDescription>Choose your preferred payment method</CardDescription>
              </CardHeader>
              <CardContent className="space-y-4">
                <form action="/api/create-checkout-session" method="POST">
                  <input type="hidden" name="registrationData" value={JSON.stringify(formData)} />
                  <input type="hidden" name="includeAccommodation" value={includeAccommodation ? "true" : "false"} />
                  <input type="hidden" name="accommodationType" value={accommodationType} />

                  <div className="space-y-4">
                    <p className="text-sm text-muted-foreground">
                      You'll be redirected to Mollie's secure checkout where you can pay by credit card,
                      SEPA bank transfer, iDEAL, PayPal, or other methods.
                    </p>

                    <div className="flex gap-3 pt-4">
                      <Button type="button" variant="outline" onClick={() => setStep("form")} className="flex-1">
                        Back to Form
                      </Button>
                      <Button type="submit" className="flex-1">
                        Proceed to Payment
                      </Button>
                    </div>
                  </div>
                </form>
              </CardContent>
            </Card>

            <div className="text-center text-sm text-muted-foreground">
              <p>
                All payments are processed securely through Mollie. You'll receive a confirmation email after successful
                payment.
              </p>
            </div>
          </div>
        </main>

        {/* Simplified Footer */}
        <footer className="py-8 px-4 border-t border-border">
          <div className="container mx-auto max-w-6xl text-center text-sm text-muted-foreground">
            <p>
              {EVENT_FULL_NAME} · {EVENT_DATES} · {EVENT_LOCATION}
            </p>
            <p className="mt-2">
              <a href={LINKS.website} className="hover:text-foreground transition-colors">
                {LINKS.website.replace("https://", "")}
              </a>
              {" · "}
              <a href={`mailto:${LINKS.contactEmail}`} className="hover:text-foreground transition-colors">
                {LINKS.contactEmail}
              </a>
            </p>
          </div>
        </footer>
      </div>
    )
  }

  return (
    <div className="min-h-screen bg-background">
      {/* Header */}
      <header className="border-b">
        <div className="container mx-auto px-4 py-4">
          <Link href={LINKS.website} className="text-2xl font-bold text-primary">
            {EVENT_SHORT}
          </Link>
        </div>
      </header>

      <main className="container mx-auto px-4 py-12 max-w-3xl">
        <div className="text-center mb-12">
          <h1 className="text-4xl md:text-5xl font-bold mb-4">Payment for CoFi 4</h1>
          <p className="text-xl text-muted-foreground">{EVENT_DATES} · {EVENT_LOCATION}</p>
        </div>

        <Card>
          <CardHeader>
            <CardTitle>Registration Form</CardTitle>
            <CardDescription>Tell us about yourself and what you'd like to bring to {EVENT_SHORT}</CardDescription>
          </CardHeader>
          <CardContent>
            <form onSubmit={handleSubmit} className="space-y-6">
              {/* Name */}
              <div className="space-y-2">
                <Label htmlFor="name">What's your name? *</Label>
                <Input
                  id="name"
                  required
                  value={formData.name}
                  onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                />
              </div>

              {/* Email */}
              <div className="space-y-2">
                <Label htmlFor="email">Email address *</Label>
                <Input
                  id="email"
                  type="email"
                  required
                  placeholder="your@email.com"
                  value={formData.email}
                  onChange={(e) => setFormData({ ...formData, email: e.target.value })}
                />
                <p className="text-sm text-muted-foreground">
                  We&apos;ll send your payment confirmation and event updates here.
                </p>
              </div>

              <div className="pt-4">
                <Button type="submit" className="w-full" size="lg" disabled={isSubmitting}>
                  {isSubmitting ? "Recording registration..." : "Continue to Payment"}
                </Button>
              </div>

              <div className="text-sm text-muted-foreground text-center">
                <p>
                  Questions? Contact us at{" "}
                  <a href={`mailto:${LINKS.contactEmail}`} className="text-primary hover:underline">
                    {LINKS.contactEmail}
                  </a>
                  {LINKS.telegram && (
                    <>
                      {" or on "}
                      <a href={LINKS.telegram} className="text-primary hover:underline">
                        Telegram
                      </a>
                    </>
                  )}
                </p>
              </div>
            </form>
          </CardContent>
        </Card>
      </main>

      {/* Simplified Footer */}
      <footer className="py-8 px-4 border-t border-border">
        <div className="container mx-auto max-w-6xl text-center text-sm text-muted-foreground">
          <p>
            {EVENT_FULL_NAME} · {EVENT_DATES} · {EVENT_LOCATION}
          </p>
          <p className="mt-2">
            <a href={LINKS.website} className="hover:text-foreground transition-colors">
              {LINKS.website.replace("https://", "")}
            </a>
            {" · "}
            <a href={`mailto:${LINKS.contactEmail}`} className="hover:text-foreground transition-colors">
              {LINKS.contactEmail}
            </a>
          </p>
        </div>
      </footer>
    </div>
  )
}