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

NAME=$(basename -- "$0")

usage() {
    echo "usage: ${NAME} [--no-auth] [-e|--endpoint ENDPOINT] [-h|--help]\
set PLM_API_KEY for authentication with ENDPOINT server";
}

# print message to fd 3, response to stdout
# If fd 3 is not open, fall back to stderr
ensure_human_fd() {
    if ! { : >&3; } 2>/dev/null; then
        exec 3>&2
    fi
}

# print message to fd 3, response to stdout
stream() {
    if [[ "$1" == "true" ]]; then
        while IFS= read -r line; do
            [[ -z "$line" ]] && continue

            if [[ "$line" == event:* ]]; then
                local current_event=${line#event: }
                continue
            fi

            if [[ "$line" == data:* ]]; then
                local payload=${line#data: }
                case "$current_event" in
                    response.output_text.delta)
                        jq -rj '.delta // empty' <<< "$payload" >&3
                        ;;
                    response.output_text.done)
                        printf '\n' >&3
                        ;;
                    response.completed)
                        jq '.response' <<< "$payload"
                        ;;
                    *)
                        if [[ -n "${PLM_DEBUG:-}" ]]; then
                            echo "event: $current_event" >&3
                            echo "data: $payload" >&3
                        fi
                        ;;
                esac
            fi
        done

        exit 0;
    fi

    local response_file=$(mktemp)
    trap "rm -f '$response_file'" RETURN

    tee "$response_file"
    jq -r '.output[] | select(.type == "message") | .content[0].text' \
       "$response_file" >&3
}

main () {
    local endpoint="${PLM_ENDPOINT:-https://api.openai.com/v1/responses}"
    local retry="${PLM_RETRY:-3}"
    local api_key_required="${PLM_API_KEY_REQUIRED:-1}"
    local api_key="${PLM_API_KEY:-"${OPENAI_API_KEY:-}"}"

    while [[ $# -gt 0 ]]; do
        case "$1" in
            -e|--endpoint) endpoint="$2"; shift 2;;
            --no-auth)     api_key_required='0'; shift;;
            -h|--help)     usage; exit 0;;
            *)             echo "unknown arg: $1" >&2; usage; exit 1;;
        esac
    done

    local auth_header=()

    if (( api_key_required != 0 )); then
        if [[ -z "${api_key:-}" ]]; then
            echo "${NAME}: missing both PLM_API_KEY and OPENAI_API_KEY" >&2
            exit 2
        fi
        auth_header=(-H "Authorization: Bearer ${api_key}")
    fi

    local request_file=$(mktemp)
    trap "rm -f '$request_file'" RETURN

    local use_stream="$(tee "$request_file" | jq .stream)"

    curl -sS -N "$endpoint" \
         -H "Content-Type: application/json" "${auth_header[@]}" \
         --retry "$retry" --retry-delay 1 \
         --data-binary @"$request_file" | stream "$use_stream"
}

main "$@"