#!/usr/bin/env bash

QGA_SOCKET="/tmp/qga.sock"

setup() {
  if [ ! -S "$QGA_SOCKET" ]; then
    echo "QGA socket not found at $QGA_SOCKET"
    exit 1
  fi
}

teardown() {
  true
}

qga_send() {
  local json_cmd="$1"
  local tmp_out
  tmp_out=$(mktemp)

  {
    echo "$json_cmd"
    sleep 0.1 
  } | socat - UNIX-CONNECT:"$QGA_SOCKET" > "$tmp_out"

  cat "$tmp_out"
  rm -f "$tmp_out"
}

qga_guest_exec() {
  local cmd="$1"
  shift

  local args_json="[]"
  if [[ "$#" -gt 0 ]]; then
    args_json=$(printf '%s\n' "$@" | jq -R . | jq -s .)
  fi

  local json
  json=$(jq -n \
    --arg path "$cmd" \
    --argjson args "$args_json" \
    '{
      execute: "guest-exec",
      arguments: {
        path: $path,
        arg: $args,
        "capture-output": true
      }
    }')

  local response
  response=$(qga_send "$json")

  echo "guest-exec JSON sent:" >&2
  echo "$json" >&2
  echo "guest-exec response:" >&2
  echo "$response" >&2

  local first_line
  first_line=$(echo "$response" | head -n1)

  local pid
  pid=$(echo "$first_line" | jq -r '.return.pid // empty')

  if [[ ! "$pid" =~ ^[0-9]+$ ]]; then
    echo "ERROR: Failed to parse valid PID from response." >&2
    return 1
  fi

  echo "$pid"
}

qga_guest_exec_status() {
  local pid="$1"

  local json
  json=$(jq -n --argjson pid "$pid" \
    '{execute: "guest-exec-status", arguments: {pid: $pid}}')

  qga_send "$json"
}

qga_decode_output() {
  local b64_data="$1"
  echo "$b64_data" | base64 -d
}

qga_run_cmd_and_get_output() {
  local pid
  pid=$(qga_guest_exec "$@")
  if [[ -z "$pid" ]]; then
    echo "Failed to get PID from guest-exec" >&2
    return 1
  fi

  local status_resp
  local exited="false"
  local retries=5

  while [[ "$exited" != "true" && $retries -gt 0 ]]; do
    sleep 0.5
    status_resp=$(qga_guest_exec_status "$pid")
    exited=$(echo "$status_resp" | jq -r '.return.exited // empty')
    retries=$((retries - 1))
  done

  if [[ "$exited" != "true" ]]; then
    echo "Command did not finish after retries." >&2
    return 1
  fi

  local out_data
  out_data=$(echo "$status_resp" | jq -r '.return."out-data" // empty')
  local err_data
  err_data=$(echo "$status_resp" | jq -r '.return."err-data" // empty')

  if [[ -n "$err_data" ]]; then
    echo "STDERR:" >&2
    qga_decode_output "$err_data" >&2
  fi

  qga_decode_output "$out_data"
}

qga_read_guest_file() {
  local file_path="$1"
  local pid
  pid=$(qga_guest_exec "/bin/cat" "$file_path")
  if [[ -z "$pid" ]]; then
    echo "Failed to get PID to read file" >&2
    return 1
  fi

  local status_resp
  local exited="false"
  local retries=5

  while [[ "$exited" != "true" && $retries -gt 0 ]]; do
    sleep 0.5
    status_resp=$(qga_guest_exec_status "$pid")
    exited=$(echo "$status_resp" | jq -r '.return.exited // empty')
    retries=$((retries - 1))
  done

  if [[ "$exited" != "true" ]]; then
    echo "Failed to read file or command did not finish execution." >&2
    return 1
  fi

  local out_data
  out_data=$(echo "$status_resp" | jq -r '.return."out-data"')
  local decoded_data
  decoded_data=$(qga_decode_output "$out_data")

  if echo "$decoded_data" | base64 --decode &>/dev/null; then
    echo "$decoded_data" | base64 --decode
  else
    echo "$decoded_data"
  fi
}