#!/usr/bin/env bash

# This script parses the ssh config at ~/.ssh/config to find user@host
# entries, then uses gum choose to select one user@host to ssh into.

# Check for gum.
if ! test -x "$(command -v gum)"; then
    echo "Missing dependency: gum"
    echo "See github.com/charmbracelet/gum"
    exit 1
fi

SSH_CONFIG="${HOME}/.ssh/config"
usern_array=()
hostn_array=()
logins=()

# Read Users from ssh config and store them in usern_array.
while IFS= read -r line; do
    if [[ "$line" == *"User"* ]]; then
        usern=$(echo "$line" | awk '{ print $2 }')
        usern_array+=("$usern")
    fi
done < "${SSH_CONFIG}"

# Read HostNames from ssh config and store them in hostn_array.
while IFS= read -r line; do
    if [[ "$line" == *"Host "* ]]; then
        hostn=$(echo $line | awk '{ print $2 }')
        hostn_array+=("$hostn")
    fi
done < "${SSH_CONFIG}"

# Set the array_len to the size of usern_array - 1.
let "array_len = ${#usern_array[@]} - 1"

# Iterate through usern_array and hostn_array and match user and host
# pairs, then store them in the logins array in "user@host" format.
for i in $(seq 0 $array_len); do
    userhost=$(printf "%s@%s" "${usern_array[i]}" "${hostn_array[i]}")
    logins+=("$userhost")
done

# Print each member of logins array on a new line and pipe to gum choose.
# Store selection.
selection=$(printf "%s\n" "${logins[@]}" | gum choose --limit=1)

# If $selection is non-empty, pass it to the ssh -X command.
if test -n "${selection}"; then
    autossh -M 0 "${selection}" -X
fi