"use client"

import { useState, useEffect } from "react"
import { useRouter } from "next/navigation"
import { Button } from "@/components/ui/button"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
import { Checkbox } from "@/components/ui/checkbox"
import { useAuth } from "@/contexts/auth-context"
import { getApiUrl } from "@/lib/api-config"

interface Vertical {
    id: number
    name: string
    slug: string
    description: string | null
}

const StarIcon = ({ filled }: { filled: boolean }) => (
    <svg
        xmlns="http://www.w3.org/2000/svg"
        viewBox="0 0 24 24"
        fill={filled ? "currentColor" : "none"}
        stroke="currentColor"
        strokeWidth="2"
        strokeLinecap="round"
        strokeLinejoin="round"
        className="w-5 h-5"
    >
        <polygon points="12 2 15.09 8.26 22 9.27 17 14.14 18.18 21.02 12 17.77 5.82 21.02 7 14.14 2 9.27 8.91 8.26 12 2" />
    </svg>
)

export function BandOnboarding({ onComplete }: { onComplete?: () => void }) {
    const [verticals, setVerticals] = useState<Vertical[]>([])
    const [loading, setLoading] = useState(true)
    const [selectedBands, setSelectedBands] = useState<number[]>([])
    const [headliners, setHeadliners] = useState<number[]>([])
    const [step, setStep] = useState<"select" | "tier">("select")
    const [submitting, setSubmitting] = useState(false)
    const { token } = useAuth()
    const router = useRouter()

    useEffect(() => {
        async function fetchVerticals() {
            try {
                const res = await fetch(`${getApiUrl()}/verticals`)
                if (res.ok) {
                    const data = await res.json()
                    setVerticals(data)
                }
            } catch (error) {
                console.error("Failed to fetch verticals", error)
            } finally {
                setLoading(false)
            }
        }
        fetchVerticals()
    }, [])

    const toggleBand = (id: number) => {
        setSelectedBands(prev =>
            prev.includes(id) ? prev.filter(b => b !== id) : [...prev, id]
        )
        // Remove from headliners if deselected
        if (headliners.includes(id)) {
            setHeadliners(prev => prev.filter(h => h !== id))
        }
    }

    const toggleHeadliner = (id: number) => {
        setHeadliners(prev => {
            if (prev.includes(id)) {
                return prev.filter(h => h !== id)
            }
            if (prev.length >= 3) {
                return prev // Limit 3
            }
            return [...prev, id]
        })
    }

    const handleContinue = () => {
        if (step === "select" && selectedBands.length > 0) {
            setStep("tier")
        } else {
            handleSubmit()
        }
    }

    const handleSubmit = async () => {
        setSubmitting(true)
        try {
            // Strategy:
            // 1. Bulk add all as 'standard'
            // 2. Update headliners to 'headliner'

            const bulkRes = await fetch(`${getApiUrl()}/verticals/preferences/bulk`, {
                method: "POST",
                headers: {
                    "Content-Type": "application/json",
                    "Authorization": `Bearer ${token}`
                },
                body: JSON.stringify({
                    vertical_ids: selectedBands,
                    display_mode: "standard"
                }),
            })

            if (!bulkRes.ok) throw new Error("Failed to save preferences")

            // Now set tiers
            await Promise.all(headliners.map(async (vid) => {
                await fetch(`${getApiUrl()}/verticals/preferences/${vid}`, {
                    method: "PUT",
                    headers: {
                        "Content-Type": "application/json",
                        "Authorization": `Bearer ${token}`
                    },
                    body: JSON.stringify({
                        tier: "headliner",
                        priority: 100 // High priority
                    }),
                })
            }))

            if (onComplete) {
                onComplete()
            } else {
                router.push("/")
            }
        } catch (error) {
            console.error("Error saving preferences", error)
        } finally {
            setSubmitting(false)
        }
    }

    if (loading) {
        return (
            <div className="flex items-center justify-center min-h-[400px]">
                <div className="text-muted-foreground">Loading bands...</div>
            </div>
        )
    }

    return (
        <div className="max-w-2xl mx-auto space-y-6">
            <div className="text-center space-y-2">
                <h1 className="text-3xl font-bold">
                    {step === "select" ? "Pick Your Bands" : "Who are your Headliners?"}
                </h1>
                <p className="text-muted-foreground">
                    {step === "select"
                        ? "Select the bands you follow. You can change this anytime."
                        : "Pick up to 3 favorites to feature on your home page."
                    }
                </p>
            </div>

            <div className="grid grid-cols-2 md:grid-cols-3 gap-4 mb-8">
                {verticals.map((vertical) => (
                    <button
                        key={vertical.id}
                        onClick={() => step === "select" ? toggleBand(vertical.id) : null}
                        disabled={step === "tier" && !selectedBands.includes(vertical.id)}
                        className={`
                            relative p-4 rounded-xl border-2 text-left transition-all
                            ${step === "select"
                                ? (selectedBands.includes(vertical.id)
                                    ? "border-primary bg-primary/10"
                                    : "border-border hover:border-primary/50")
                                : (selectedBands.includes(vertical.id)
                                    ? "border-primary/50 opacity-100"
                                    : "border-border opacity-20 grayscale")
                            }
                            ${step === "tier" && selectedBands.includes(vertical.id) ? "cursor-default" : ""}
                        `}
                    >
                        <div className="font-bold">{vertical.name}</div>
                        <div className="text-sm text-muted-foreground">{vertical.description}</div>

                        {step === "tier" && selectedBands.includes(vertical.id) && (
                            <div
                                onClick={(e) => {
                                    e.stopPropagation()
                                    toggleHeadliner(vertical.id)
                                }}
                                className={`
                                    absolute top-2 right-2 p-1 rounded-full cursor-pointer transition-colors z-10
                                    ${headliners.includes(vertical.id) ? "bg-yellow-500 text-black" : "bg-muted text-muted-foreground hover:bg-muted/80"}
                                `}
                            >
                                <StarIcon filled={headliners.includes(vertical.id)} />
                            </div>
                        )}
                    </button>
                ))}
            </div>

            <div className="flex justify-between items-center bg-card p-4 rounded-lg border">
                <div className="text-sm font-medium">
                    {step === "select"
                        ? `${selectedBands.length} selected`
                        : `${headliners.length}/3 Headliners selected`
                    }
                </div>
                <div className="flex gap-2">
                    {step === "tier" && (
                        <Button variant="ghost" onClick={() => setStep("select")}>
                            Back
                        </Button>
                    )}
                    <Button
                        onClick={handleContinue}
                        disabled={submitting || (step === "select" && selectedBands.length === 0)}
                        size="lg"
                    >
                        {submitting ? "Saving..." : (step === "select" ? "Next: Choose Headliners" : "Finish")}
                    </Button>
                </div>
            </div>
        </div>
    )
}