#!/usr/bin/env bash
set -euo pipefail

# Compute next CalVer version: YYYY.MM.BUILD
# Queries the Anvil release API via curl (no anvil binary needed).
# Increments build number within the current month, resets on new month.

command -v jq >/dev/null 2>&1 || { echo "error: jq is required" >&2; exit 1; }
command -v curl >/dev/null 2>&1 || { echo "error: curl is required" >&2; exit 1; }

ANVIL_SERVER="${ANVIL_SERVER_URL:-https://anvil.fangorn.io}"
REPO="${ANVIL_REPO:-fangorn/anvil-cli}"
YEAR_MONTH=$(date +"%Y.%m")

if [ -z "${ANVIL_TOKEN:-}" ]; then
    echo "error: ANVIL_TOKEN is required" >&2
    exit 1
fi

TMP=$(mktemp)
trap 'rm -f "$TMP"' EXIT

if ! curl -sf -H "Authorization: Bearer $ANVIL_TOKEN" \
        "${ANVIL_SERVER}/api/v1/${REPO}/releases" > "$TMP"; then
    echo "error: release API request failed" >&2
    exit 1
fi

LATEST=$(jq -r '
    .releases
    | [.[] | select(.tag_name | test("^[0-9]{4}\\.[0-9]{2}\\.[0-9]+$"))]
    | sort_by(.tag_name | split(".") | map(tonumber))
    | .[-1].tag_name // empty
' < "$TMP")

if [ -z "$LATEST" ]; then
    echo "${YEAR_MONTH}.1"
    exit 0
fi

LATEST_YM=$(echo "$LATEST" | cut -d. -f1-2)
LATEST_BUILD=$(echo "$LATEST" | cut -d. -f3)

if [ "$LATEST_YM" = "$YEAR_MONTH" ]; then
    echo "${YEAR_MONTH}.$((LATEST_BUILD + 1))"
else
    echo "${YEAR_MONTH}.1"
fi