#!/usr/bin/env bash
# gstack-screenshot-upload — upload a screenshot to gstack.gg
#
# Usage:
#   gstack-screenshot-upload <file> [--repo-slug X] [--branch X] [--viewport X]
#
# Uploads a PNG to gstack.gg and prints the proxy URL (with watermark) to stdout.
# All diagnostics go to stderr. Exit 0 = success, 1 = error.
#
# Env overrides (for testing):
#   GSTACK_STATE_DIR     — override ~/.gstack state directory
#   GSTACK_DIR           — override auto-detected gstack root
#   GSTACK_WEB_URL       — override gstack.gg URL
set -euo pipefail

GSTACK_DIR="${GSTACK_DIR:-$(cd "$(dirname "$0")/.." && pwd)}"
STATE_DIR="${GSTACK_STATE_DIR:-$HOME/.gstack}"

# Source config
if [ -f "$GSTACK_DIR/supabase/config.sh" ]; then
  . "$GSTACK_DIR/supabase/config.sh"
fi
WEB_URL="${GSTACK_WEB_URL:-https://gstack.gg}"

# ─── Parse args ───────────────────────────────────────────────────
FILE=""
REPO_SLUG=""
BRANCH=""
VIEWPORT=""

while [ $# -gt 0 ]; do
  case "$1" in
    --repo-slug) REPO_SLUG="$2"; shift 2 ;;
    --branch)    BRANCH="$2"; shift 2 ;;
    --viewport)  VIEWPORT="$2"; shift 2 ;;
    -*)          echo "Unknown option: $1" >&2; exit 1 ;;
    *)           FILE="$1"; shift ;;
  esac
done

if [ -z "$FILE" ]; then
  echo "Usage: gstack-screenshot-upload <file.png> [--repo-slug X] [--branch X] [--viewport X]" >&2
  exit 1
fi

if [ ! -f "$FILE" ]; then
  echo "Error: file not found: $FILE" >&2
  exit 1
fi

# ─── Validate PNG ─────────────────────────────────────────────────
MIME=$(file --mime-type -b "$FILE" 2>/dev/null || echo "unknown")
if [ "$MIME" != "image/png" ]; then
  echo "Error: only PNG files are supported (got $MIME)" >&2
  exit 1
fi

# ─── Slugify helper ───────────────────────────────────────────────
slugify() {
  echo "$1" | tr '[:upper:]' '[:lower:]' | sed 's|/|-|g; s|[^a-z0-9._-]||g'
}

[ -n "$REPO_SLUG" ] && REPO_SLUG="$(slugify "$REPO_SLUG")"
[ -n "$BRANCH" ] && BRANCH="$(slugify "$BRANCH")"

# ─── Pre-upload compression ──────────────────────────────────────
FILE_SIZE=$(wc -c < "$FILE" | tr -d ' ')
UPLOAD_FILE="$FILE"

if [ "$FILE_SIZE" -gt 2097152 ]; then  # > 2MB
  echo "File is $(( FILE_SIZE / 1024 ))KB — compressing..." >&2
  TMPFILE="$(mktemp /tmp/gstack-compress-XXXXXX.png)"

  if command -v sips >/dev/null 2>&1; then
    # macOS: sips resize to max 1920px wide
    cp "$FILE" "$TMPFILE"
    sips --resampleWidth 1920 "$TMPFILE" >/dev/null 2>&1 && UPLOAD_FILE="$TMPFILE"
  elif command -v magick >/dev/null 2>&1; then
    # ImageMagick 7+
    magick "$FILE" -resize '1920x>' "$TMPFILE" 2>/dev/null && UPLOAD_FILE="$TMPFILE"
  elif command -v convert >/dev/null 2>&1; then
    # ImageMagick 6
    convert "$FILE" -resize '1920x>' "$TMPFILE" 2>/dev/null && UPLOAD_FILE="$TMPFILE"
  else
    echo "Warning: no resize tool available (sips/magick/convert), uploading raw" >&2
  fi

  if [ "$UPLOAD_FILE" = "$TMPFILE" ]; then
    NEW_SIZE=$(wc -c < "$TMPFILE" | tr -d ' ')
    echo "Compressed: $(( FILE_SIZE / 1024 ))KB → $(( NEW_SIZE / 1024 ))KB" >&2
  fi
fi

# ─── Check file size limit ────────────────────────────────────────
FINAL_SIZE=$(wc -c < "$UPLOAD_FILE" | tr -d ' ')
if [ "$FINAL_SIZE" -gt 10485760 ]; then  # 10MB
  echo "Error: file too large ($(( FINAL_SIZE / 1024 ))KB, max 10MB)" >&2
  exit 1
fi

# ─── Get auth token ───────────────────────────────────────────────
if ! "$GSTACK_DIR/bin/gstack-auth-refresh" --check >/dev/null 2>&1; then
  echo "Error: not authenticated. Run: gstack-auth" >&2
  exit 1
fi

ACCESS_TOKEN="$("$GSTACK_DIR/bin/gstack-auth-refresh" 2>/dev/null)"
if [ -z "$ACCESS_TOKEN" ]; then
  echo "Error: failed to get auth token" >&2
  exit 1
fi

# ─── Upload ───────────────────────────────────────────────────────
HTTP_RESPONSE="$(curl -s -w "\n%{http_code}" \
  --max-time 30 \
  -X POST "${WEB_URL}/api/images/upload" \
  -H "Authorization: Bearer ${ACCESS_TOKEN}" \
  -F "file=@${UPLOAD_FILE}" \
  -F "repo_slug=${REPO_SLUG}" \
  -F "branch=${BRANCH}" \
  -F "viewport=${VIEWPORT}" \
  2>/dev/null || echo -e "\n000")"

HTTP_CODE="$(echo "$HTTP_RESPONSE" | tail -1)"
HTTP_BODY="$(echo "$HTTP_RESPONSE" | sed '$d')"

# Clean up temp file
[ "$UPLOAD_FILE" != "$FILE" ] && rm -f "$UPLOAD_FILE" 2>/dev/null

case "$HTTP_CODE" in
  2*)
    # Extract proxy URL from response JSON
    URL="$(echo "$HTTP_BODY" | jq -r '.url' 2>/dev/null || echo "")"
    if [ -n "$URL" ] && [ "$URL" != "null" ]; then
      echo "$URL"  # stdout: proxy URL only
    else
      echo "Error: upload succeeded but no URL in response" >&2
      echo "$HTTP_BODY" >&2
      exit 1
    fi
    ;;
  401)
    echo "Error: authentication failed (401). Re-run: gstack-auth" >&2
    exit 1
    ;;
  413)
    echo "Error: file too large (413)" >&2
    exit 1
    ;;
  415)
    echo "Error: unsupported file type (415). Only PNG supported." >&2
    exit 1
    ;;
  *)
    echo "Error: upload failed (HTTP ${HTTP_CODE})" >&2
    [ -n "$HTTP_BODY" ] && echo "$HTTP_BODY" >&2
    exit 1
    ;;
esac