#!/bin/bash
set -euo pipefail

# ── Colors ───────────────────────────────────────────────────────────
RED='\033[0;31m'
YELLOW='\033[1;33m'
NC='\033[0m'

# ── Logging ──────────────────────────────────────────────────────────
log_error() { printf "${RED}[ERR]${NC}  %s\n" "$*" >&2; }
log_warn()  { printf "${YELLOW}[WARN]${NC} %s\n" "$*" >&2; }

# ── Usage ────────────────────────────────────────────────────────────
usage() {
    cat <<EOF
Usage: $(basename "$0") [OPTIONS] PROJECT_ID

Get project name from GitLab by its numeric ID.

Options:
    -h, --help               Show this help
    -t, --token-file=FILE    File containing the GitLab personal access token
    -g, --gitlab-url=URL     GitLab instance URL (default: https://git.mws-team.ru)

Examples:
    $(basename "$0") -t ~/.gitlab_token 42
    $(basename "$0") --token-file=token.txt --gitlab-url=https://gitlab.com 123
EOF
    exit 1
}

# ── Dependency check ─────────────────────────────────────────────────
for cmd in curl jq; do
    if ! command -v "$cmd" &>/dev/null; then
        log_error "Required command not found: ${cmd}"
        exit 1
    fi
done

# ── Parse arguments ──────────────────────────────────────────────────
GITLAB_URL="https://git.mws-team.ru"
TOKEN_FILE=""

translated=()
while (( $# )); do
    case "$1" in
        --help)          translated+=("-h"); shift ;;
        --token-file=*)  translated+=("-t" "${1#*=}"); shift ;;
        --gitlab-url=*)  translated+=("-g" "${1#*=}"); shift ;;
        --)              translated+=("--"); shift; translated+=("$@"); break ;;
        *)               translated+=("$1"); shift ;;
    esac
done
set -- "${translated[@]}"

while getopts ":ht:g:" opt; do
    case "$opt" in
        h)  usage ;;
        t)  TOKEN_FILE="$OPTARG" ;;
        g)  GITLAB_URL="$OPTARG" ;;
        :)  log_error "Missing argument for -${OPTARG}"; usage ;;
        \?) log_error "Invalid option: -${OPTARG}"; usage ;;
    esac
done
shift $((OPTIND - 1))

# Positional argument: project ID
PROJECT_ID="${1:-}"

# ── Validate inputs ─────────────────────────────────────────────────
[[ -z "$TOKEN_FILE" ]]   && { log_error "Missing --token-file"; usage; }
[[ ! -f "$TOKEN_FILE" ]] && { log_error "Token file not found: ${TOKEN_FILE}"; exit 1; }
[[ -z "$PROJECT_ID" ]]   && { log_error "Missing PROJECT_ID"; usage; }

if ! [[ "$PROJECT_ID" =~ ^[0-9]+$ ]]; then
    log_error "PROJECT_ID must be a positive integer, got '${PROJECT_ID}'"
    exit 1
fi

GITLAB_URL="${GITLAB_URL%/}"

TOKEN="$(<"$TOKEN_FILE")"
readonly TOKEN GITLAB_URL PROJECT_ID

# ── Fetch project info ──────────────────────────────────────────────
response="$(curl --silent --fail \
    --header "Authorization: Bearer ${TOKEN}" \
    "${GITLAB_URL}/api/v4/projects/${PROJECT_ID}")" || {
    log_error "API request failed for project ${PROJECT_ID}"
    exit 1
}

# If the API returned an error message, show it; otherwise print project details.
echo "$response" | jq '
    if has("message") then
        .message
    else
        {name, name_with_namespace, path_with_namespace}
    end
'