import { NextResponse } from "next/server"
import { auth } from "@/lib/auth"
import { prisma } from "@/lib/prisma"
import { getUserProvider } from "@/lib/ai/provider-factory"
import { FEATURE_ROUTING } from "@/lib/ai/routing"
import { aiErrorResponse } from "@/lib/ai/errors"
import { rateLimit } from "@/lib/rate-limit"
import { WHAT_CAN_I_MAKE_PROMPT, buildBarInventoryString } from "@/lib/ai/prompts"
import { fuzzyMatchIngredients, recalculateMissingCount } from "@/lib/ingredient-matcher"

export async function POST() {
  const session = await auth()
  if (!session?.user?.id) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
  }

  const { success: withinLimit } = rateLimit(`bartender-suggest:${session.user.id}`, 5, 60000)
  if (!withinLimit) {
    return NextResponse.json(
      { error: "Too many requests. Please wait a moment." },
      { status: 429 }
    )
  }

  try {
    const barItems = await prisma.barItem.findMany({
      where: {
        userId: session.user.id,
        quantity: { not: "EMPTY" },
      },
      select: { name: true, category: true, quantity: true },
    })

    if (barItems.length === 0) {
      return NextResponse.json(
        { error: "No items in your bar inventory. Add items to your bar first." },
        { status: 400 }
      )
    }

    const inventoryString = buildBarInventoryString(barItems)
    const prompt = WHAT_CAN_I_MAKE_PROMPT.replace("{barInventory}", inventoryString)

    const provider = await getUserProvider(session.user.id)

    const rawResponse = await provider.sendTextRequest(
      prompt,
      "What cocktails can I make with my bar inventory?",
      FEATURE_ROUTING.bartenderSuggest
    )

    // Parse JSON from response
    let suggestions
    try {
      suggestions = JSON.parse(rawResponse)
    } catch {
      const codeBlockMatch = rawResponse.match(/```(?:json)?\s*\n?([\s\S]*?)\n?```/)
      if (codeBlockMatch) {
        suggestions = JSON.parse(codeBlockMatch[1].trim())
      } else {
        const arrayMatch = rawResponse.match(/\[[\s\S]*\]/)
        if (arrayMatch) {
          suggestions = JSON.parse(arrayMatch[0])
        } else {
          throw new Error("Could not parse suggestions from AI response")
        }
      }
    }

    if (!Array.isArray(suggestions)) {
      suggestions = []
    }

    // Post-process: fuzzy-match ingredients against bar inventory and re-sort
    if (barItems.length > 0) {
      suggestions = suggestions.map((s: { ingredients?: { name: string; amount: string; available: boolean }[]; missingCount?: number }) => {
        if (s.ingredients && Array.isArray(s.ingredients)) {
          s.ingredients = fuzzyMatchIngredients(s.ingredients, barItems)
          s.missingCount = recalculateMissingCount(s.ingredients)
        }
        return s
      })
      // Re-sort by missingCount ascending
      suggestions.sort((a: { missingCount?: number }, b: { missingCount?: number }) =>
        (a.missingCount ?? 99) - (b.missingCount ?? 99)
      )
    }

    return NextResponse.json({ suggestions })
  } catch (error) {
    return aiErrorResponse(error, "Failed to generate suggestions. Please try again.")
  }
}