// UsingResolverBox — static, stateful resolver helpers（インスタンス禁止・VM互換）
// State layout (Map): {
//   alias_paths: Map, alias_names: Map, alias_keys: Array,
//   modules_map: Map, modules_keys: Array
// }

using selfhost.shared.common.string_helpers as StringHelpers
using selfhost.shared.common.box_helpers as BoxHelpers
using lang.compiler.pipeline_v2.regex_flow as RegexFlow

static box UsingResolverBox {
  // Lightweight state as String: holds modules_json only
  state_new() { return "" }

  load_usings_json(state, usings_json) { return state }

  load_modules_json(state, mod_json) { return ("" + mod_json) }

  resolve_path_alias(state, alias) { return null }

  resolve_namespace_alias(state, alias) {
    if alias == null { return null }
    local s = "" + state
    // Prefer unique tail match by last segment
    local i = 0
    local start = 0
    local found = null
    loop(true) {
      local kpos = RegexFlow.find_from(s, "\"", start)
      if kpos < 0 { break }
      local kend = RegexFlow.find_from(s, "\"", kpos + 1)
      if kend < 0 { break }
      local key = s.substring(kpos + 1, kend)
      local dot = RegexFlow.last_index_of(key, ".")
      local last = key
      if dot >= 0 { last = key.substring(dot + 1, key.length()) }
      if last == alias {
        if found == null { found = key } else { return null }
      } else {
        // first-letter case-insensitive match
        if last.length() == alias.length() && last.length() > 0 {
          local l0 = last.substring(0,1)
          local a0 = alias.substring(0,1)
          local restl = last.substring(1, last.length())
          local resta = alias.substring(1, alias.length())
          if restl == resta {
            local U = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; local L = "abcdefghijklmnopqrstuvwxyz"
            local idxL = L.indexOf(l0); local idxU = U.indexOf(l0)
            if (idxL >= 0 && U.substring(idxL, idxL+1) == a0) || (idxU >= 0 && L.substring(idxU, idxU+1) == a0) {
              if found == null { found = key } else { return null }
            }
          }
        }
      }
      start = kend + 1
    }
    return found
  }

  resolve_module_path_from_alias(state, alias) { return null }

  guess_namespace_from_tail(state, tail) { return me.resolve_namespace_alias(state, tail) }

  upgrade_aliases(state) { return 0 }

  to_context_json(state) { return "{}" }
  map_to_json(m) { return "{}" }
}

static box UsingResolverBoxMain { main(args) { return 0 } }