local domain = require("clever_f.domain")

local M = {}
local AcquisitionRequest = {}
local AcquisitionService = {}
AcquisitionService.__index = AcquisitionService
M.AcquisitionRequest = AcquisitionRequest
M.AcquisitionService = AcquisitionService

local request_records = setmetatable({}, { __mode = "k" })
local service_records = setmetatable({}, { __mode = "k" })

local function fail(message, level)
  error(message, (level or 1) + 1)
end

local function normalize_macro_state(value)
  if type(value) == "table" and not domain.MacroState.is(value) then
    value = value.register
  end
  return domain.MacroState.new(value)
end

local request_metatable = {
  __index = function(request, key)
    local method = AcquisitionRequest[key]
    if method ~= nil then
      return method
    end
    return request_records[request][key]
  end,
  __newindex = function()
    fail("AcquisitionRequest values are immutable", 2)
  end,
  __tostring = function(request)
    return "acquisition-request:" .. request_records[request].descriptor.value
  end,
  __metatable = "clever_f.acquisition_service.AcquisitionRequest",
}

function AcquisitionRequest.new(descriptor, context, position, count, macro_state)
  if AcquisitionRequest.is(descriptor) then
    return descriptor
  end
  if type(descriptor) == "table" and not domain.Descriptor.is(descriptor) then
    local options = descriptor
    descriptor = options.descriptor
    context = options.context
    position = options.position or options.origin
    count = options.count
    macro_state = options.macro_state
  end

  local request = setmetatable({}, request_metatable)
  request_records[request] = {
    descriptor = domain.Descriptor.from_string(descriptor),
    context = domain.ModeContext.from_full_mode(context),
    position = domain.Position.coerce(position),
    count = domain.Count.new(count),
    macro_state = normalize_macro_state(macro_state),
  }
  return request
end

function AcquisitionRequest.is(value)
  return type(value) == "table" and request_records[value] ~= nil
end

function AcquisitionRequest:to_table()
  return {
    descriptor = self.descriptor.value,
    context = self.context.key,
    position = self.position:to_table(),
    count = self.count.value,
    macro_register = self.macro_state.register,
  }
end

local function normalize_options(options, dependencies)
  if AcquisitionService.is(options) and dependencies == nil then
    return options
  end
  if type(options) ~= "table" then
    fail("AcquisitionService options must be a table", 3)
  end
  if options.host ~= nil then
    if dependencies ~= nil then
      fail("AcquisitionService dependencies must be part of its options", 3)
    end
    return options
  end
  local result = {}
  for key, value in pairs(dependencies or {}) do
    result[key] = value
  end
  result.host = options
  return result
end

function AcquisitionService.new(options, dependencies)
  options = normalize_options(options, dependencies)
  if AcquisitionService.is(options) then
    return options
  end
  if type(options.host) ~= "table" then
    fail("AcquisitionService host must be a table", 2)
  end
  local service = setmetatable({}, AcquisitionService)
  service_records[service] = {
    host = options.host,
  }
  return service
end

function AcquisitionService.is(value)
  return type(value) == "table" and service_records[value] ~= nil
end

function AcquisitionService:request(descriptor, context, position, count, macro_state)
  return AcquisitionRequest.new(descriptor, context, position, count, macro_state)
end

function AcquisitionService:acquire(descriptor, context, position, count, macro_state)
  return self:request(descriptor, context, position, count, macro_state)
end

function M.new(options, dependencies)
  return AcquisitionService.new(options, dependencies)
end

setmetatable(M, {
  __call = function(_, options, dependencies)
    return AcquisitionService.new(options, dependencies)
  end,
})

return M