#!/bin/sh
# Open a git repo's web page in the browser — host-agnostic, so it works for
# github.com, prad.codes (Gitea), or any other forge whose web layout is
# https://<host>/<owner>/<repo> (all of them, in practice).
#
# Usage: gop [<remote> | <owner>/<repo> | <url>]
#   no arg → origin, else upstream, else the first remote of the current repo
#   bare owner/repo → github.com

target=$1
url=

if [ -n "$target" ]; then
    case $target in
        *://* | *@*:* | */*) url=$target ;;  # explicit url / scp / owner/repo
        *)
            url=$(git remote get-url "$target" 2>/dev/null) || {
                echo "gop: no remote named '$target'" >&2
                exit 1
            }
            ;;
    esac
else
    for remote in origin upstream $(git remote 2>/dev/null); do
        url=$(git remote get-url "$remote" 2>/dev/null) && break
        url=
    done
    if [ -z "$url" ]; then
        echo "gop: not in a git repo, or it has no remotes" >&2
        exit 1
    fi
fi

# Reduce any remote form to <host>/<owner>/<repo>. The web page is https
# unless the remote itself says plain http (a LAN forge, typically).
proto=https
case $url in
    *://*)
        # scheme form: drop scheme and credentials; drop the port for ssh/git
        # (their port is not the web port), keep it for http/https.
        scheme=${url%%://*}
        rest=${url#*://}
        rest=${rest#*@}
        case $scheme in
            ssh | git)
                host=${rest%%/*}
                rest="${host%%:*}/${rest#*/}"
                ;;
            http) proto=http ;;
        esac
        url=$rest
        ;;
    *@*:*)
        # scp form: git@host:owner/repo
        url=$(printf '%s\n' "${url#*@}" | sed 's#:#/#')
        ;;
esac
url=${url%.git}
url=${url%/}
case $url in
    */*/*) ;;                 # already host/owner/repo
    */*) url=github.com/$url ;;
    *)
        echo "gop: could not parse a repo out of: ${target:-$url}" >&2
        exit 1
        ;;
esac

exec ${BROWSER:-xdg-open} "$proto://$url"