#!/usr/bin/env bash
# commands/hosts.command.sh
#
# Manages /etc/hosts entries for the project.
#
# Usage:
#   dx hosts sync      — write project entries to /etc/hosts (requires root)
#   dx hosts remove    — remove project entries from /etc/hosts (requires root)
#   dx hosts list      — show current /etc/hosts entries for this project
#   dx hosts preview   — preview entries that would be written
#
# Also accessible via:
#   dx network hosts <subcommand>

# ============================================
# Lifecycle
# ============================================

function cmd::hosts::on_load() {
  flag::register \
    --debug
}

# ============================================
# Public entrypoint
# ============================================

function cmd::hosts::run() {
  local subcmd="${1:-help}"
  shift || true

  case "$subcmd" in
    sync)    cmd::hosts::sync    "$@" ;;
    remove)  cmd::hosts::remove  "$@" ;;
    list)    cmd::hosts::list    "$@" ;;
    preview) cmd::hosts::preview "$@" ;;
    help)    cmd::hosts::help ;;
    *)
      log::error "Unknown subcommand: '${subcmd}'"
      cmd::hosts::help
      return 1
      ;;
  esac
}

# ============================================
# Help
# ============================================

function cmd::hosts::help() {
  cat <<EOF
Usage: dx hosts <subcommand>

Manages /etc/hosts entries for ${PROJECT_NAME}.

Subcommands:
  sync      Write project entries to /etc/hosts (requires root)
  remove    Remove project entries from /etc/hosts (requires root)
  list      Show current entries in /etc/hosts for this project
  preview   Preview entries that would be written

Examples:
  dx hosts sync
  dx hosts remove
  dx hosts list
  dx hosts preview
EOF
}

# ============================================
# Sync
# ============================================

function cmd::hosts::sync() {
  local hosts_file
  hosts_file="$(platform::hosts_file)"

  platform::require_privileges || {
    log::warn "$(platform::elevation_fail)"
    log::error "Could not sync hosts — permission denied"
    return 1
  }

  local block
  block="$(cmd::hosts::_build_block)"

  [[ -f "$hosts_file" ]] || touch "$hosts_file" || return 1

  local tmp
  tmp="$(fs::replace_block \
    "$hosts_file" \
    "$(cmd::hosts::_marker)" \
    "$(cmd::hosts::_end_marker)" \
    "$block"
  )" || return 1

  fs::write_file "$tmp" "$hosts_file"

  log::success "Hosts synced for ${PROJECT_NAME}"
  cmd::hosts::_show_entries "$block"
}

# ============================================
# Remove
# ============================================

function cmd::hosts::remove() {
  local hosts_file
  hosts_file="$(platform::hosts_file)"

  platform::require_privileges || {
    log::warn "$(platform::elevation_fail)"
    log::error "Could not remove hosts — permission denied"
    return 1
  }

  if ! grep -q "$(cmd::hosts::_marker)" "$hosts_file" 2>/dev/null; then
    log::info "No entries found for ${PROJECT_NAME} in $(platform::hosts_file)"
    return 0
  fi

  local tmp
  tmp="$(fs::replace_block \
    "$hosts_file" \
    "$(cmd::hosts::_marker)" \
    "$(cmd::hosts::_end_marker)" \
    ""
  )" || return 1

  fs::write_file "$tmp" "$hosts_file"

  log::success "Hosts entries removed for ${PROJECT_NAME}"
}

# ============================================
# List
# ============================================

function cmd::hosts::list() {
  local hosts_file
  hosts_file="$(platform::hosts_file)"

  if ! grep -q "$(cmd::hosts::_marker)" "$hosts_file" 2>/dev/null; then
    log::info "No entries found for ${PROJECT_NAME} in ${hosts_file}"
    return 0
  fi

  log::info "Current entries for ${PROJECT_NAME} in ${hosts_file}:"
  printf "\n"

  # Extract block between markers
  awk "/$(cmd::hosts::_marker)/,/$(cmd::hosts::_end_marker)/" "$hosts_file" \
    | grep -v "^#"
  printf "\n"
}

# ============================================
# Preview
# ============================================

function cmd::hosts::preview() {
  log::info "Entries that would be written for ${PROJECT_NAME}:"
  printf "\n"
  cmd::hosts::_generate_entries
  printf "\n"
}

# ============================================
# Private
# ============================================

function cmd::hosts::_marker()     { echo "# >>> ${PROJECT_NAME} >>>"; }
function cmd::hosts::_end_marker() { echo "# <<< ${PROJECT_NAME} <<<"; }

function cmd::hosts::_generate_entries() {
  local ip="127.0.0.1"

  local domains=(
    "$DOMAIN"
    "$BACKEND_DOMAIN"
  )

  for domain in "${domains[@]}"; do
    echo "${ip} ${domain}"
  done
}

function cmd::hosts::_build_block() {
  local entries
  entries="$(cmd::hosts::_generate_entries | tr -d '\r')"

  printf "%s\n%s\n%s" \
    "$(cmd::hosts::_marker)" \
    "$entries" \
    "$(cmd::hosts::_end_marker)"
}

function cmd::hosts::_show_entries() {
  local entries="$1"
  printf "\n"
  echo "$entries"
  printf "\n"
}