#!/usr/bin/env bash

wl_area_index() {
  case "$1" in
    frontend) printf '0' ;;
    backend) printf '1' ;;
    specs) printf '2' ;;
    docs) printf '3' ;;
    *) return 1 ;;
  esac
}

wl_trim() {
  local value=$1
  value=${value#"${value%%[![:space:]]*}"}
  value=${value%"${value##*[![:space:]]}"}
  printf '%s' "$value"
}

wl_parse_delivery_map() {
  local metadata_file=$1
  local design_file=$2
  local raw_area raw_status raw_reason area status reason gate index

  wl_areas=(frontend backend specs docs)
  wl_affected_flags=(0 0 0 0)
  wl_map_statuses=('' '' '' '')
  wl_map_reasons=('' '' '' '')
  wl_contract_status=''
  wl_contract_reason=''

  while IFS= read -r area; do
    [[ -n "$area" ]] || continue
    if ! index=$(wl_area_index "$area"); then
      printf 'Unknown affected area in metadata: %s\n' "$area" >&2
      return 1
    fi
    if [[ "${wl_affected_flags[$index]}" -eq 1 ]]; then
      printf 'Duplicate affected area in metadata: %s\n' "$area" >&2
      return 1
    fi
    wl_affected_flags[$index]=1
  done < <(
    awk '
      $0 == "affected_areas:" { in_areas = 1; next }
      in_areas && /^  - / { sub(/^  - /, ""); print; next }
      in_areas { exit }
    ' "$metadata_file"
  )

  if [[ "${wl_affected_flags[2]}" -ne 1 ]]; then
    printf 'Delivery Map violation: specs must be affected for every versioned change.\n' >&2
    return 1
  fi

  while IFS='|' read -r _ raw_area raw_status raw_reason _; do
    area=$(wl_trim "$raw_area")
    case "$area" in
      frontend|backend|specs|docs) ;;
      *) continue ;;
    esac
    index=$(wl_area_index "$area")
    if [[ -n "${wl_map_statuses[$index]}" ]]; then
      printf 'Delivery Map contains duplicate row for %s.\n' "$area" >&2
      return 1
    fi
    status=$(wl_trim "$raw_status")
    status=${status//\`/}
    reason=$(wl_trim "$raw_reason")
    wl_map_statuses[$index]=$status
    wl_map_reasons[$index]=$reason
  done < "$design_file"

  while IFS='|' read -r _ raw_area raw_status raw_reason _; do
    gate=$(wl_trim "$raw_area")
    [[ "$gate" == 'runtime-openapi' ]] || continue
    if [[ -n "$wl_contract_status" ]]; then
      printf 'Contract Gate Decision contains duplicate runtime-openapi row.\n' >&2
      return 1
    fi
    wl_contract_status=$(wl_trim "$raw_status")
    wl_contract_status=${wl_contract_status//\`/}
    wl_contract_reason=$(wl_trim "$raw_reason")
  done < "$design_file"

  for index in 0 1 2 3; do
    area=${wl_areas[$index]}
    status=${wl_map_statuses[$index]}
    reason=${wl_map_reasons[$index]}
    if [[ -z "$status" ]]; then
      printf 'Delivery Map is missing area: %s\n' "$area" >&2
      return 1
    fi
    if [[ "${wl_affected_flags[$index]}" -eq 1 ]]; then
      if [[ "$status" != 'affected' ]]; then
        printf 'Delivery Map mismatch: %s is listed as affected in metadata but has status %s.\n' "$area" "$status" >&2
        return 1
      fi
    elif [[ "$status" != 'N/A' ]]; then
      printf 'Delivery Map mismatch: %s is absent from affected_areas but has status %s.\n' "$area" "$status" >&2
      return 1
    fi
    if [[ -z "$reason" || "$reason" == '-' || "$reason" == '—' || "$reason" == *'<!--'* ]]; then
      printf 'Delivery Map requires a concrete outcome or N/A reason for %s.\n' "$area" >&2
      return 1
    fi
  done

  if [[ -z "$wl_contract_status" ]]; then
    printf 'Contract Gate Decision is missing runtime-openapi.\n' >&2
    return 1
  fi
  if [[ "$wl_contract_status" != 'required' && "$wl_contract_status" != 'N/A' ]]; then
    printf 'Invalid runtime-openapi decision: %s. Expected required or N/A.\n' "$wl_contract_status" >&2
    return 1
  fi
  if [[ -z "$wl_contract_reason" || "$wl_contract_reason" == '-' || "$wl_contract_reason" == '—' || "$wl_contract_reason" == *'<!--'* ]]; then
    printf 'Contract Gate Decision requires a concrete runtime-openapi reason.\n' >&2
    return 1
  fi
  if [[ "$wl_contract_status" == 'required' && ( "${wl_affected_flags[0]}" -ne 1 || "${wl_affected_flags[1]}" -ne 1 ) ]]; then
    printf 'runtime-openapi cannot be required unless frontend and backend are affected.\n' >&2
    return 1
  fi
}