package main

import (
	"image"
	"net/http"
	"strconv"
	"strings"

	"github.com/chai2010/webp"
	xdraw "golang.org/x/image/draw"
	"inou/lib"
)

func handleImage(w http.ResponseWriter, r *http.Request) {
	ctx := getAccessContextOrFail(w, r)
	if ctx == nil {
		return
	}

	hexID := strings.TrimPrefix(r.URL.Path, "/image/")
	if len(hexID) != 16 {
		http.Error(w, "Invalid ID", http.StatusBadRequest)
		return
	}

	opts := &lib.ImageOpts{}
	if wc := r.URL.Query().Get("wc"); wc != "" {
		opts.WC, _ = strconv.ParseFloat(wc, 64)
	}
	if ww := r.URL.Query().Get("ww"); ww != "" {
		opts.WW, _ = strconv.ParseFloat(ww, 64)
	}

	img, err := lib.ImageGet(ctx.AccessorID, hexID, opts)
	if err != nil {
		http.Error(w, "Image not found", http.StatusNotFound)
		return
	}

	// Resize if either dimension exceeds maxDim (default 2000 for Claude API)
	maxDim := 2000
	if md := r.URL.Query().Get("maxdim"); md != "" {
		if v, err := strconv.Atoi(md); err == nil && v > 0 {
			maxDim = v
		}
	}
	bounds := img.Bounds()
	w0, h0 := bounds.Dx(), bounds.Dy()
	if w0 > maxDim || h0 > maxDim {
		scale := float64(maxDim) / float64(max(w0, h0))
		newW := int(float64(w0) * scale)
		newH := int(float64(h0) * scale)
		resized := image.NewRGBA(image.Rect(0, 0, newW, newH))
		xdraw.BiLinear.Scale(resized, resized.Bounds(), img, bounds, xdraw.Over, nil)
		img = resized
	}

	w.Header().Set("Content-Type", "image/webp")
	w.Header().Set("Cache-Control", "public, max-age=86400")
	webp.Encode(w, img, &webp.Options{Lossless: true})
}