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

# ── helpers ────────────────────────────────────────────────────────────────────

die() { echo "Error: $*" >&2; exit 1; }

# Returns the latest vX.Y.Z tag for a given X.Y prefix (or overall latest if no prefix)
fetch_latest_version() {
    local prefix="$1"   # e.g. "11.0" or "" for absolute latest
    local tags

    tags=$(curl -fsSL \
        "https://codeberg.org/api/v1/repos/forgejo/forgejo/tags?limit=50" \
        2>/dev/null) || die "Could not reach Codeberg API — check your connection."

    # Extract tag names, filter to release tags (vX.Y.Z, no pre-release suffix)
    local versions
    versions=$(echo "$tags" | grep -oP '"name"\s*:\s*"\Kv[0-9]+\.[0-9]+\.[0-9]+"' \
        | tr -d '"' | sort -V)

    if [[ -z "$prefix" ]]; then
        echo "$versions" | tail -1
    else
        echo "$versions" | grep "^v${prefix}\." | tail -1
    fi
}

# ── detect architecture ────────────────────────────────────────────────────────

case "$(uname -m)" in
    x86_64)  ARCH="amd64" ;;
    aarch64) ARCH="arm64" ;;
    armv7l)  ARCH="arm-6" ;;
    *) die "Unsupported architecture: $(uname -m)" ;;
esac

# ── version prompt ─────────────────────────────────────────────────────────────

echo "Fetching latest Forgejo release…"
LATEST_OVERALL=$(fetch_latest_version "")
LATEST_OVERALL="${LATEST_OVERALL#v}"   # strip leading 'v'

echo
echo "Latest available release: ${LATEST_OVERALL}"
echo
read -rp "Version to install [MAJOR.MINOR or MAJOR.MINOR.PATCH, Enter = ${LATEST_OVERALL}]: " INPUT
INPUT="${INPUT:-$LATEST_OVERALL}"

# Normalise: strip a leading 'v' if the user typed one
INPUT="${INPUT#v}"

# Determine if the user gave a full version (X.Y.Z) or a partial one (X.Y)
if [[ "$INPUT" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
    # Full version supplied — use as-is
    VERSION="$INPUT"
elif [[ "$INPUT" =~ ^[0-9]+\.[0-9]+$ ]]; then
    # Partial (X.Y) — resolve the latest patch on that line
    echo "Resolving latest patch for ${INPUT}.x…"
    RESOLVED=$(fetch_latest_version "$INPUT")
    [[ -z "$RESOLVED" ]] && die "No releases found for ${INPUT}.x"
    VERSION="${RESOLVED#v}"
    echo "→ Using ${VERSION}"
else
    die "Unrecognised version format '${INPUT}'. Use X.Y or X.Y.Z"
fi

# ── confirm ────────────────────────────────────────────────────────────────────

BINARY="forgejo-${VERSION}-linux-${ARCH}"
echo
echo "  Version : ${VERSION}"
echo "  Binary  : ${BINARY}"
echo "  Arch    : ${ARCH}"
echo
read -rp "Proceed with installation? [Y/n]: " CONFIRM
CONFIRM="${CONFIRM:-Y}"
[[ "$CONFIRM" =~ ^[Yy]$ ]] || { echo "Aborted."; exit 0; }

# ── download & install ─────────────────────────────────────────────────────────

URL="https://codeberg.org/forgejo/forgejo/releases/download/v${VERSION}/${BINARY}"
echo
echo "Downloading ${URL}…"
wget --show-progress -q "$URL" || die "Download failed — is v${VERSION} a valid release?"

chmod +x "$BINARY"

echo "Stopping forgejo…"
systemctl stop forgejo

echo "Installing binary…"
cp "$BINARY" /usr/local/bin/forgejo
rm -f "$BINARY"   # clean up the downloaded file

echo "Starting forgejo…"
systemctl start forgejo

echo
echo "Done — Forgejo ${VERSION} is running."