'use client'

import { useState, useMemo, useEffect } from 'react'
import { useRouter } from 'next/navigation'
import { useSession } from 'next-auth/react'
import { trpc } from '@/lib/trpc/client'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { PhoneInput } from '@/components/ui/phone-input'
import { CountrySelect } from '@/components/ui/country-select'
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import { Slider } from '@/components/ui/slider'
import { cn } from '@/lib/utils'
import { toast } from 'sonner'
import { ExpertiseSelect } from '@/components/shared/expertise-select'
import { AvatarUpload } from '@/components/shared/avatar-upload'
import { Textarea } from '@/components/ui/textarea'
import {
  User,
  Phone,
  Tags,
  Bell,
  CheckCircle,
  Loader2,
  ArrowRight,
  ArrowLeft,
  Camera,
  Globe,
  FileText,
  Scale,
} from 'lucide-react'
import { AnimatedCard } from '@/components/shared/animated-container'

type Step = 'name' | 'photo' | 'country' | 'bio' | 'phone' | 'tags' | 'jury' | 'preferences' | 'complete'

type JuryPref = {
  juryGroupMemberId: string
  juryGroupName: string
  currentCap: number
  allowCapAdjustment: boolean
  allowRatioAdjustment: boolean
  selfServiceCap: number | null
  selfServiceRatio: number | null
}

export default function OnboardingPage() {
  const router = useRouter()
  const { data: session, status: sessionStatus } = useSession()
  const isAuthenticated = sessionStatus === 'authenticated'
  const [step, setStep] = useState<Step>('name')
  const [initialized, setInitialized] = useState(false)

  // Form state
  const [name, setName] = useState('')
  const [country, setCountry] = useState('')
  const [bio, setBio] = useState('')
  const [phoneNumber, setPhoneNumber] = useState('')
  const [expertiseTags, setExpertiseTags] = useState<string[]>([])
  const [lockedTags, setLockedTags] = useState<string[]>([])
  const [notificationPreference, setNotificationPreference] = useState<
    'EMAIL' | 'WHATSAPP' | 'BOTH' | 'NONE'
  >('EMAIL')
  const [juryPrefs, setJuryPrefs] = useState<Map<string, { cap?: number; ratio?: number }>>(new Map())

  // Fetch current user data only after session is hydrated
  const { data: userData, isLoading: userLoading, refetch: refetchUser } = trpc.user.me.useQuery(
    undefined,
    { enabled: isAuthenticated }
  )
  const { data: avatarUrl } = trpc.avatar.getUrl.useQuery(
    undefined,
    { enabled: isAuthenticated }
  )

  // Initialize form with user data
  useEffect(() => {
    if (userData && !initialized) {
      // Pre-fill name if available
      if (userData.name) {
        setName(userData.name)
      }
      // Pre-fill country if available
      if (userData.country) {
        setCountry(userData.country)
      }
      // Pre-fill bio if available
      if (userData.bio) {
        setBio(userData.bio)
      }
      // Pre-fill phone if available
      if (userData.phoneNumber) {
        setPhoneNumber(userData.phoneNumber)
      }
      // Set admin-preset tags as both locked and selected
      if (userData.expertiseTags && userData.expertiseTags.length > 0) {
        setLockedTags(userData.expertiseTags)
        setExpertiseTags(userData.expertiseTags)
      }
      // Pre-fill notification preference if available
      if (userData.notificationPreference) {
        setNotificationPreference(userData.notificationPreference)
      }
      setInitialized(true)
    }
  }, [userData, initialized])

  // Fetch jury onboarding context
  const { data: onboardingCtx } = trpc.user.getOnboardingContext.useQuery(
    undefined,
    { enabled: isAuthenticated }
  )
  const juryMemberships: JuryPref[] = onboardingCtx?.memberships ?? []
  const hasJuryStep = onboardingCtx?.hasSelfServiceOptions ?? false

  // Fetch feature flags only after session is hydrated
  const { data: featureFlags } = trpc.settings.getFeatureFlags.useQuery(
    undefined,
    { enabled: isAuthenticated }
  )
  const whatsappEnabled = featureFlags?.whatsappEnabled ?? false

  const utils = trpc.useUtils()
  const completeOnboarding = trpc.user.completeOnboarding.useMutation({
    onSuccess: () => utils.user.me.invalidate(),
  })

  // Dynamic steps based on WhatsApp availability and jury self-service
  const steps: Step[] = useMemo(() => {
    const base: Step[] = ['name', 'photo', 'country', 'bio']
    if (whatsappEnabled) base.push('phone')
    base.push('tags')
    if (hasJuryStep) base.push('jury')
    base.push('preferences', 'complete')
    return base
  }, [whatsappEnabled, hasJuryStep])

  const currentIndex = steps.indexOf(step)
  const totalVisibleSteps = steps.length - 1 // Exclude 'complete' from count

  const goNext = () => {
    if (step === 'name' && !name.trim()) {
      toast.error('Please enter your name')
      return
    }
    const nextIndex = currentIndex + 1
    if (nextIndex < steps.length) {
      setStep(steps[nextIndex])
    }
  }

  const goBack = () => {
    const prevIndex = currentIndex - 1
    if (prevIndex >= 0) {
      setStep(steps[prevIndex])
    }
  }

  const handleComplete = async () => {
    try {
      // Build jury preferences from state
      const juryPreferences = juryMemberships
        .map((m) => {
          const pref = juryPrefs.get(m.juryGroupMemberId)
          if (!pref) return null
          return {
            juryGroupMemberId: m.juryGroupMemberId,
            selfServiceCap: pref.cap,
            selfServiceRatio: pref.ratio,
          }
        })
        .filter(Boolean) as Array<{
          juryGroupMemberId: string
          selfServiceCap?: number
          selfServiceRatio?: number
        }>

      await completeOnboarding.mutateAsync({
        name,
        country: country || undefined,
        bio: bio || undefined,
        phoneNumber: phoneNumber || undefined,
        expertiseTags,
        notificationPreference,
        juryPreferences: juryPreferences.length > 0 ? juryPreferences : undefined,
      })
      setStep('complete')
      toast.success('Welcome to MOPC!')

      // Redirect after a short delay based on user role
      setTimeout(() => {
        const role = userData?.role
        if (role === 'SUPER_ADMIN' || role === 'PROGRAM_ADMIN') {
          router.push('/admin')
        } else if (role === 'MENTOR') {
          router.push('/mentor')
        } else if (role === 'OBSERVER') {
          router.push('/observer')
        } else {
          router.push('/jury')
        }
      }, 2000)
    } catch (error) {
      toast.error(error instanceof Error ? error.message : 'Failed to complete onboarding')
    }
  }

  // Show loading while session hydrates or fetching user data
  if (sessionStatus === 'loading' || userLoading || !initialized) {
    return (
      <div className="absolute inset-0 -m-4 flex items-center justify-center p-4 md:p-8 bg-[#053d57] bg-[url('https://s3.monaco-opc.com/public/ocean.png')] bg-cover bg-center bg-no-repeat">
        <AnimatedCard>
        <Card className="w-full max-w-lg shadow-2xl overflow-hidden">
          <div className="h-1 w-full bg-gradient-to-r from-brand-blue via-brand-teal to-brand-blue" />
          <CardContent className="flex flex-col items-center justify-center py-12">
            <Loader2 className="h-8 w-8 animate-spin text-primary mb-4" />
            <p className="text-muted-foreground">Loading your profile...</p>
          </CardContent>
        </Card>
        </AnimatedCard>
      </div>
    )
  }

  return (
    <div className="absolute inset-0 -m-4 flex items-center justify-center p-4 md:p-8 bg-[#053d57] bg-[url('https://s3.monaco-opc.com/public/ocean.png')] bg-cover bg-center bg-no-repeat">
      <AnimatedCard>
      <Card className="w-full max-w-lg max-h-[85vh] overflow-y-auto overflow-hidden shadow-2xl">
        <div className="h-1 w-full bg-gradient-to-r from-brand-blue via-brand-teal to-brand-blue" />
        {/* Progress indicator */}
        <div className="px-6 pt-6">
          <div className="flex items-center gap-2">
            {steps.slice(0, -1).map((s, i) => (
              <div key={s} className="flex items-center flex-1">
                <div
                  className={`h-2 flex-1 rounded-full transition-colors ${
                    i < currentIndex
                      ? 'bg-primary'
                      : i === currentIndex
                        ? 'bg-primary/60'
                        : 'bg-muted'
                  }`}
                />
              </div>
            ))}
          </div>
          {/* Step labels */}
          <div className="flex items-center gap-2 mt-1">
            {steps.slice(0, -1).map((s, i) => {
              const labels: Record<string, string> = {
                name: 'Name',
                photo: 'Photo',
                country: 'Country',
                bio: 'About',
                phone: 'Phone',
                tags: 'Expertise',
                jury: 'Jury',
                preferences: 'Settings',
              }
              return (
                <div key={s} className="flex-1 text-center">
                  <span className={cn(
                    'text-[10px]',
                    i <= currentIndex ? 'text-primary font-medium' : 'text-muted-foreground'
                  )}>
                    {labels[s] || s}
                  </span>
                </div>
              )
            })}
          </div>
          <p className="text-sm text-muted-foreground mt-2">
            Step {currentIndex + 1} of {totalVisibleSteps}
          </p>
        </div>

        {/* Step 1: Name */}
        {step === 'name' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <User className="h-5 w-5 text-primary" />
                Welcome to MOPC
              </CardTitle>
              <CardDescription>
                Let&apos;s get your profile set up. What should we call you?
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="name">Full Name</Label>
                <Input
                  id="name"
                  value={name}
                  onChange={(e) => setName(e.target.value)}
                  placeholder="Enter your full name"
                  autoFocus
                />
              </div>

              <Button onClick={goNext} className="w-full" disabled={!name.trim()}>
                Continue
                <ArrowRight className="ml-2 h-4 w-4" />
              </Button>
            </CardContent>
          </>
        )}

        {/* Step 2: Profile Photo */}
        {step === 'photo' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Camera className="h-5 w-5 text-primary" />
                Profile Photo
              </CardTitle>
              <CardDescription>
                Add a profile photo so others can recognize you. This step is optional.
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="flex justify-center">
                <AvatarUpload
                  user={{
                    name: userData?.name,
                    email: userData?.email,
                    profileImageKey: userData?.profileImageKey,
                  }}
                  currentAvatarUrl={avatarUrl}
                  onUploadComplete={() => refetchUser()}
                />
              </div>
              <p className="text-sm text-muted-foreground text-center">
                Click the avatar to upload a new photo. You can crop and adjust before saving.
              </p>

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  {avatarUrl ? 'Continue' : 'Skip for now'}
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Step 3: Home Country */}
        {step === 'country' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Globe className="h-5 w-5 text-primary" />
                Home Country
              </CardTitle>
              <CardDescription>
                Select your home country. This helps us match you with relevant projects.
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="country">Country</Label>
                <CountrySelect
                  value={country}
                  onChange={setCountry}
                  placeholder="Select your country"
                />
              </div>

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  Continue
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Step 4: Bio */}
        {step === 'bio' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <FileText className="h-5 w-5 text-primary" />
                About You
              </CardTitle>
              <CardDescription>
                Tell us a bit about yourself and your expertise. This helps us match you with relevant projects. (Optional)
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="bio">Bio</Label>
                <Textarea
                  id="bio"
                  value={bio}
                  onChange={(e) => setBio(e.target.value)}
                  placeholder="e.g., Marine biologist with 10 years experience in coral reef conservation and ocean acidification research..."
                  rows={4}
                  maxLength={500}
                />
                <p className="text-xs text-muted-foreground text-right">
                  {bio.length}/500 characters
                </p>
              </div>

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  {bio ? 'Continue' : 'Skip for now'}
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Step 5: Phone (only if WhatsApp enabled) */}
        {step === 'phone' && whatsappEnabled && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Phone className="h-5 w-5 text-primary" />
                Contact Information
              </CardTitle>
              <CardDescription>
                Optionally add your phone number for WhatsApp notifications
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="phone">Phone Number (Optional)</Label>
                <PhoneInput
                  id="phone"
                  value={phoneNumber}
                  onChange={(value) => setPhoneNumber(value || '')}
                  defaultCountry="MC"
                  placeholder="Enter phone number"
                />
                <p className="text-xs text-muted-foreground">
                  Select your country and enter your number for WhatsApp notifications
                </p>
              </div>

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  Continue
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Step 6: Tags */}
        {step === 'tags' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Tags className="h-5 w-5 text-primary" />
                Your Expertise
              </CardTitle>
              <CardDescription>
                Select tags that describe your areas of expertise. This helps us match you with relevant projects.
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <ExpertiseSelect
                value={expertiseTags}
                onChange={setExpertiseTags}
                maxTags={5}
                lockedTags={lockedTags}
              />

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  Continue
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Jury Preferences Step (conditional) */}
        {step === 'jury' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Scale className="h-5 w-5 text-primary" />
                Jury Preferences
              </CardTitle>
              <CardDescription>
                Customize your assignment preferences for each jury panel you belong to.
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-6">
              {juryMemberships.map((m) => {
                const pref = juryPrefs.get(m.juryGroupMemberId) ?? {}
                const capValue = pref.cap ?? m.selfServiceCap ?? m.currentCap
                const ratioValue = pref.ratio ?? m.selfServiceRatio ?? 0.5

                return (
                  <div key={m.juryGroupMemberId} className="rounded-lg border p-4 space-y-4">
                    <h4 className="font-medium text-sm">{m.juryGroupName}</h4>

                    {m.allowCapAdjustment && (
                      <div className="space-y-2">
                        <Label className="text-xs text-muted-foreground">
                          Maximum assignments: {capValue}
                        </Label>
                        <Slider
                          value={[capValue]}
                          onValueChange={([v]) =>
                            setJuryPrefs((prev) => {
                              const next = new Map(prev)
                              next.set(m.juryGroupMemberId, { ...pref, cap: v })
                              return next
                            })
                          }
                          min={1}
                          max={m.currentCap}
                          step={1}
                        />
                        <p className="text-xs text-muted-foreground">
                          Admin default: {m.currentCap}. You may reduce this to match your availability.
                        </p>
                      </div>
                    )}

                    {m.allowRatioAdjustment && (
                      <div className="space-y-2">
                        <Label className="text-xs text-muted-foreground">
                          Startup vs Business Concept ratio: {Math.round(ratioValue * 100)}% / {Math.round((1 - ratioValue) * 100)}%
                        </Label>
                        <Slider
                          value={[ratioValue * 100]}
                          onValueChange={([v]) =>
                            setJuryPrefs((prev) => {
                              const next = new Map(prev)
                              next.set(m.juryGroupMemberId, { ...pref, ratio: v / 100 })
                              return next
                            })
                          }
                          min={0}
                          max={100}
                          step={5}
                        />
                        <div className="flex justify-between text-xs text-muted-foreground">
                          <span>More Business Concepts</span>
                          <span>More Startups</span>
                        </div>
                      </div>
                    )}
                  </div>
                )
              })}

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button onClick={goNext} className="flex-1">
                  Continue
                  <ArrowRight className="ml-2 h-4 w-4" />
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Notification Preferences */}
        {step === 'preferences' && (
          <>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Bell className="h-5 w-5 text-primary" />
                Notification Preferences
              </CardTitle>
              <CardDescription>
                How would you like to receive notifications?
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="notifications">Notification Channel</Label>
                <Select
                  value={notificationPreference}
                  onValueChange={(v) =>
                    setNotificationPreference(v as typeof notificationPreference)
                  }
                >
                  <SelectTrigger id="notifications">
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="EMAIL">Email only</SelectItem>
                    {whatsappEnabled && (
                      <>
                        <SelectItem value="WHATSAPP" disabled={!phoneNumber}>
                          WhatsApp only
                        </SelectItem>
                        <SelectItem value="BOTH" disabled={!phoneNumber}>
                          Both Email and WhatsApp
                        </SelectItem>
                      </>
                    )}
                    <SelectItem value="NONE">No notifications</SelectItem>
                  </SelectContent>
                </Select>
                {whatsappEnabled && !phoneNumber && (
                  <p className="text-xs text-muted-foreground">
                    Add a phone number to enable WhatsApp notifications
                  </p>
                )}
              </div>

              <div className="rounded-lg border p-4 bg-muted/50">
                <h4 className="font-medium mb-2">Summary</h4>
                <div className="space-y-1 text-sm">
                  <p>
                    <span className="text-muted-foreground">Name:</span> {name}
                  </p>
                  {country && (
                    <p>
                      <span className="text-muted-foreground">Country:</span> {country}
                    </p>
                  )}
                  {bio && (
                    <p>
                      <span className="text-muted-foreground">Bio:</span>{' '}
                      {bio.length > 50 ? `${bio.substring(0, 50)}...` : bio}
                    </p>
                  )}
                  {whatsappEnabled && phoneNumber && (
                    <p>
                      <span className="text-muted-foreground">Phone:</span>{' '}
                      {phoneNumber}
                    </p>
                  )}
                  <p>
                    <span className="text-muted-foreground">Expertise:</span>{' '}
                    {expertiseTags.length > 0
                      ? expertiseTags.join(', ')
                      : 'None selected'}
                  </p>
                </div>
              </div>

              <div className="flex gap-2">
                <Button variant="outline" onClick={goBack} className="flex-1">
                  <ArrowLeft className="mr-2 h-4 w-4" />
                  Back
                </Button>
                <Button
                  onClick={handleComplete}
                  className="flex-1"
                  disabled={completeOnboarding.isPending}
                >
                  {completeOnboarding.isPending ? (
                    <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                  ) : (
                    <CheckCircle className="mr-2 h-4 w-4" />
                  )}
                  Complete Setup
                </Button>
              </div>
            </CardContent>
          </>
        )}

        {/* Step 7: Complete */}
        {step === 'complete' && (
          <CardContent className="flex flex-col items-center justify-center py-12">
            <div className="rounded-2xl bg-emerald-50 p-4 mb-4 animate-in zoom-in-50 duration-500">
              <CheckCircle className="h-12 w-12 text-green-600" />
            </div>
            <h2 className="text-xl font-semibold mb-2 animate-in fade-in slide-in-from-bottom-2 duration-500 delay-200">
              Welcome, {name}!
            </h2>
            <p className="text-muted-foreground text-center mb-4">
              Your profile is all set up. You&apos;ll be redirected to your dashboard
              shortly.
            </p>
            <Loader2 className="h-6 w-6 animate-spin text-primary" />
          </CardContent>
        )}
      </Card>
      </AnimatedCard>
    </div>
  )
}