#!/usr/bin/env bash

# ===========================================
# System
# ===========================================
function system::uuid() {
  od -x /dev/urandom | head -1 | awk '{OFS="-"; print $2$3,$4,$5,$6,$7$8$9}'
}
function system::hosts() {
  cat "$(platform::hosts_file)"
}
function system::stderr() {
  "$1" >&2
}

# ===========================================
# Path
# ===========================================
function path::relative_to_root() {
  local abs="$1"
  local root="$(ctx::root)"

  # remove root prefix
  echo "${abs#$root/}"
}

function path::from_root() {
  local path="$1"
  [[ "$path" == /* ]] && echo "$path" || echo "$(ctx::root)/${path}"
}

function path::relative_to() {
  local from="$1"
  local to="$2"

  # ===========================================
  # 1. GNU realpath (best case)
  # ===========================================
  if platform::has_gnu_realpath; then
      realpath --relative-to="$from" "$to"
      return 0
  fi

  # ===========================================
  # 2. Homebrew GNU coreutils
  # ===========================================
  if platform::has_grealpath; then
    grealpath --relative-to="$from" "$to"
    return 0
  fi

  # ===========================================
  # 3. Python fallback (POSIX-safe)
  # ===========================================
  if platform::has_python; then
      python3 -c '
  import os, sys
  print(os.path.relpath(sys.argv[2], sys.argv[1]))
  ' "$from" "$to"
      return 0
    fi

  # ===========================================
  # 4. Hard failure
  # ===========================================
  echo "path::relative_to: no suitable backend found" >&2
  return 1
}

# ===========================================
# Core
# ===========================================

# Returns true if stdout is connected to a real TTY.
# Used to decide whether winpty or interactive flags are needed.
# False inside $(), pipes, or non-interactive subshells.
function core::has_tty()         { [[ -t 1 ]]; }      # stdout is a TTY
function core::is_interactive()  { [[ $- == *i* ]]; }  # shell is interactive mode
function core::function_exists() { declare -F "$1" >/dev/null 2>&1;  }
function core::variable_exists() { declare -p "$1" &>/dev/null; }
function core::array_exists()    { [[ "$(declare -p "$1" 2>/dev/null)" == "declare -a"* ]]; }

function core::call_function() {
  local fn="$1"
  shift

  "$fn" "$@";
}

function core::call_if_exists() {
  local fn="$1"
  shift

  if declare -F "$fn" >/dev/null 2>&1; then
    "$fn" "$@"
  fi

  return 0
}