require "test_helper"

class TransfersControllerTest < ActionDispatch::IntegrationTest
  setup do
    sign_in users(:family_admin)
  end

  test "should get new" do
    get new_transfer_url
    assert_response :success
  end

  test "excludes disabled accounts from the new transfer form" do
    disabled_account = accounts(:depository)
    disabled_account.update!(status: "disabled")

    get new_transfer_url

    assert_response :success
    assert_no_match disabled_account.name, response.body
  end

  test "can create transfers" do
    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer"
        }
      }
      assert_enqueued_with job: SyncJob
    end
  end

  test "resubmitting the same idempotency key does not create a duplicate transfer" do
    idempotency_key = SecureRandom.uuid
    params = {
      transfer: {
        from_account_id: accounts(:depository).id,
        to_account_id: accounts(:credit_card).id,
        date: Date.current,
        amount: 100,
        name: "Test Transfer",
        idempotency_key: idempotency_key
      }
    }

    assert_difference "Transfer.count", 1 do
      assert_difference "Entry.count", 2 do
        post transfers_url, params: params
      end
    end
    first_transfer = Transfer.order(:created_at).last

    # Simulates a double-click or a browser retry: same form, same
    # idempotency key, submitted again after the first request already
    # completed and committed.
    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: params
    end
    assert_redirected_to transactions_path
  end

  test "the idempotency key does not mark either leg as provider-linked" do
    # Regression test: the key must not be stored in external_id/source
    # (Entry#linked? = external_id.present?), or an ordinary manual transfer
    # would incorrectly look provider-synced.
    post transfers_url, params: {
      transfer: {
        from_account_id: accounts(:depository).id,
        to_account_id: accounts(:credit_card).id,
        date: Date.current,
        amount: 100,
        name: "Test Transfer",
        source_fee_amount: 3,
        idempotency_key: SecureRandom.uuid
      }
    }

    transfer = Transfer.order(:created_at).last
    [ transfer.outflow_transaction.entry, transfer.inflow_transaction.entry, transfer.fee_transactions.first.entry ].each do |entry|
      assert_not entry.linked?
      assert_nil entry.external_id
      assert_nil entry.source
    end
  end

  test "each leg gets a distinct idempotency key so fee legs don't collide with their primary leg" do
    # Regression test: the outflow/source-fee share source_account, and the
    # inflow/destination-fee share destination_account. The unique index is
    # scoped per account_id, so without role-specific suffixes a fee leg
    # would collide with its primary leg under the same idempotency key.
    post transfers_url, params: {
      transfer: {
        from_account_id: accounts(:depository).id,
        to_account_id: accounts(:credit_card).id,
        date: Date.current,
        amount: 100,
        name: "Test Transfer",
        source_fee_amount: 2,
        destination_fee_amount: 3,
        idempotency_key: SecureRandom.uuid
      }
    }

    transfer = Transfer.order(:created_at).last
    keys = [
      transfer.outflow_transaction.entry.idempotency_key,
      transfer.inflow_transaction.entry.idempotency_key,
      transfer.fee_transactions.map { |t| t.entry.idempotency_key }
    ].flatten

    assert_equal keys.uniq.length, keys.length
    assert keys.all?(&:present?)
  end

  test "handles a genuine concurrent double-submit without raising or duplicating" do
    idempotency_key = SecureRandom.uuid
    from_account = accounts(:depository)
    to_account = accounts(:credit_card)

    # Simulates the race: another request with the same idempotency key wins
    # and commits its transfer in the window between our pre-check (which
    # therefore still sees nothing, hence the first `nil`) and our own
    # Transfer#save! (which then hits the real partial unique index on
    # entries(account_id, idempotency_key) and raises RecordNotUnique,
    # exactly like the DB would under real concurrent requests). The rescue
    # then re-runs the same lookup, this time finding the winner.
    winning_transfer = Transfer::Creator.new(
      family: users(:family_admin).family,
      source_account_id: from_account.id,
      destination_account_id: to_account.id,
      date: Date.current,
      amount: 100,
      idempotency_key: idempotency_key
    ).create
    Transfer::Creator.any_instance.stubs(:find_existing_transfer).returns(nil, winning_transfer)
    Transfer.any_instance.stubs(:save!).raises(ActiveRecord::RecordNotUnique.new("duplicate key value violates unique constraint"))

    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: {
        transfer: {
          from_account_id: from_account.id,
          to_account_id: to_account.id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          idempotency_key: idempotency_key
        }
      }
    end

    assert_redirected_to transactions_path
  end

  test "a RecordNotUnique with no matching transfer is not silently swallowed" do
    idempotency_key = SecureRandom.uuid

    # Defensive-branch coverage: if the unique index ever rejects an insert
    # for a reason other than "another request with this exact idempotency
    # key already won," we must not pretend it succeeded - it should
    # surface as a stale-form error instead of a raw DB exception.
    Transfer::Creator.any_instance.stubs(:find_existing_transfer).returns(nil)
    Transfer.any_instance.stubs(:save!).raises(ActiveRecord::RecordNotUnique.new("duplicate key value violates unique constraint"))

    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          idempotency_key: idempotency_key
        }
      }
    end

    assert_response :unprocessable_entity
  end

  test "reusing a key for a genuinely different request does not silently return the old transfer" do
    idempotency_key = SecureRandom.uuid
    from_account = accounts(:depository)
    to_account = accounts(:credit_card)
    other_destination = accounts(:other_liability)

    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: from_account.id,
          to_account_id: to_account.id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          idempotency_key: idempotency_key
        }
      }
    end

    # Simulates a stale hidden field (cached page / reopened dialog) still
    # carrying the first request's key while the user changed the
    # destination account before resubmitting.
    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: {
        transfer: {
          from_account_id: from_account.id,
          to_account_id: other_destination.id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          idempotency_key: idempotency_key
        }
      }
    end

    assert_response :unprocessable_entity
  end

  test "reusing a key with a different fee does not silently return the old transfer" do
    idempotency_key = SecureRandom.uuid
    from_account = accounts(:depository)
    to_account = accounts(:credit_card)

    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: from_account.id,
          to_account_id: to_account.id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          idempotency_key: idempotency_key
        }
      }
    end

    # Same accounts/date/amount/key as the first request, but a fee was
    # added before resubmitting - the persisted effect differs, so this
    # must not be reported as a successful retry of the fee-less transfer.
    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: {
        transfer: {
          from_account_id: from_account.id,
          to_account_id: to_account.id,
          date: Date.current,
          amount: 100,
          name: "Test Transfer",
          source_fee_amount: 5,
          idempotency_key: idempotency_key
        }
      }
    end

    assert_response :unprocessable_entity
  end

  test "reusing a key with a different exchange rate does not silently return the old transfer" do
    idempotency_key = SecureRandom.uuid
    usd_account = accounts(:depository)
    eur_account = users(:family_admin).family.accounts.create!(
      name: "EUR Account",
      balance: 1000,
      currency: "EUR",
      accountable: Depository.new
    )

    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: usd_account.id,
          to_account_id: eur_account.id,
          date: Date.current,
          amount: 100,
          exchange_rate: 0.9,
          idempotency_key: idempotency_key
        }
      }
    end

    # Same accounts/date/amount/key, but a different exchange rate - the
    # persisted inflow amount would differ, so this must not be reported as
    # a successful retry of the first, differently-converted transfer.
    assert_no_difference [ "Transfer.count", "Entry.count" ] do
      post transfers_url, params: {
        transfer: {
          from_account_id: usd_account.id,
          to_account_id: eur_account.id,
          date: Date.current,
          amount: 100,
          exchange_rate: 0.5,
          idempotency_key: idempotency_key
        }
      }
    end

    assert_response :unprocessable_entity
  end

  test "can create transfer with custom exchange rate" do
    usd_account = accounts(:depository)
    eur_account = users(:family_admin).family.accounts.create!(
      name: "EUR Account",
      balance: 1000,
      currency: "EUR",
      accountable: Depository.new
    )

    assert_equal "USD", usd_account.currency
    assert_equal "EUR", eur_account.currency

    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: usd_account.id,
          to_account_id: eur_account.id,
          date: Date.current,
          amount: 100,
          exchange_rate: 0.92
        }
      }
    end

    transfer = Transfer.where(
      "outflow_transaction_id IN (?) AND inflow_transaction_id IN (?)",
      usd_account.transactions.pluck(:id),
      eur_account.transactions.pluck(:id)
    ).last
    assert_not_nil transfer
    assert_equal "USD", transfer.outflow_transaction.entry.currency
    assert_equal "EUR", transfer.inflow_transaction.entry.currency
    assert_equal 100, transfer.outflow_transaction.entry.amount
    assert_in_delta(-92, transfer.inflow_transaction.entry.amount, 0.01)
  end

  test "exchange_rate endpoint returns 400 when from currency is missing" do
    get exchange_rate_url, params: {
      to: "USD"
    }

    assert_response :bad_request
    json_response = JSON.parse(response.body)
    assert_equal "from and to currencies are required", json_response["error"]
  end

  test "exchange_rate endpoint returns 400 when to currency is missing" do
    get exchange_rate_url, params: {
      from: "EUR"
    }

    assert_response :bad_request
    json_response = JSON.parse(response.body)
    assert_equal "from and to currencies are required", json_response["error"]
  end

  test "exchange_rate endpoint returns 400 on invalid date format" do
    get exchange_rate_url, params: {
      from: "EUR",
      to: "USD",
      date: "not-a-date"
    }

    assert_response :bad_request
    json_response = JSON.parse(response.body)
    assert_equal "Invalid date format", json_response["error"]
  end

  test "exchange_rate endpoint returns rate for different currencies" do
    ExchangeRate.expects(:find_or_fetch_rate)
                .with(from: "USD", to: "EUR", date: Date.current)
                .returns(OpenStruct.new(rate: 0.92))

    get exchange_rate_url, params: {
      from: "USD",
      to: "EUR",
      date: Date.current.to_s
    }

    assert_response :success
    json_response = JSON.parse(response.body)
    assert_equal 0.92, json_response["rate"]
  end

  test "exchange_rate endpoint returns error when exchange rate unavailable" do
    ExchangeRate.expects(:find_or_fetch_rate)
                .with(from: "USD", to: "EUR", date: Date.current)
                .returns(nil)

    get exchange_rate_url, params: {
      from: "USD",
      to: "EUR",
      date: Date.current.to_s
    }

    assert_response :not_found
    json_response = JSON.parse(response.body)
    assert_equal "Exchange rate not found", json_response["error"]
  end

  test "cannot create transfer when exchange rate unavailable and no custom rate provided" do
    usd_account = accounts(:depository)
    eur_account = users(:family_admin).family.accounts.create!(
      name: "EUR Account",
      balance: 1000,
      currency: "EUR",
      accountable: Depository.new
    )

    ExchangeRate.stubs(:find_or_fetch_rate).returns(nil)

    assert_no_difference "Transfer.count" do
      post transfers_url, params: {
        transfer: {
          from_account_id: usd_account.id,
          to_account_id: eur_account.id,
          date: Date.current,
          amount: 100
        }
      }
    end

    assert_response :unprocessable_entity
  end

  test "can create transfer with source fee" do
    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          source_fee_amount: 3
        }
      }
    end

    transfer = Transfer.order(created_at: :desc).first
    assert_equal 100, transfer.amount
    assert_equal 3, transfer.derived_source_fee_amount
    assert_equal 0, transfer.derived_destination_fee_amount
    # Outflow should be principal only (no fee baked in)
    assert_equal 100, transfer.outflow_transaction.entry.amount
    # Inflow should be -(converted_principal)
    assert_equal(-100, transfer.inflow_transaction.entry.amount)
    # Fee transaction should be created
    assert_equal 1, transfer.fee_transactions.count
    fee_tx = transfer.fee_transactions.first
    assert_equal "standard", fee_tx.kind
    assert_equal 3, fee_tx.entry.amount
    assert_equal accounts(:depository).id, fee_tx.entry.account_id
    assert transfer.has_source_fee?
    assert_not transfer.has_destination_fee?
  end

  test "can create transfer with destination fee" do
    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          destination_fee_amount: 3
        }
      }
    end

    transfer = Transfer.order(created_at: :desc).first
    assert_equal 100, transfer.amount
    assert_equal 0, transfer.derived_source_fee_amount
    assert_equal 3, transfer.derived_destination_fee_amount
    # Outflow should be principal only
    assert_equal 100, transfer.outflow_transaction.entry.amount
    # Inflow should be -(converted_principal)
    assert_equal(-100, transfer.inflow_transaction.entry.amount)
    # Fee transaction should be created
    assert_equal 1, transfer.fee_transactions.count
    fee_tx = transfer.fee_transactions.first
    assert_equal "standard", fee_tx.kind
    assert_equal 3, fee_tx.entry.amount
    assert_equal accounts(:credit_card).id, fee_tx.entry.account_id
    assert_not transfer.has_source_fee?
    assert transfer.has_destination_fee?
  end

  test "can create transfer with both source and destination fees" do
    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          source_fee_amount: 2,
          destination_fee_amount: 3
        }
      }
    end

    transfer = Transfer.order(created_at: :desc).first
    assert_equal 100, transfer.amount
    assert_equal 2, transfer.derived_source_fee_amount
    assert_equal 3, transfer.derived_destination_fee_amount
    # Outflow should be principal only
    assert_equal 100, transfer.outflow_transaction.entry.amount
    # Inflow should be -(converted_principal)
    assert_equal(-100, transfer.inflow_transaction.entry.amount)
    # Two fee transactions should be created
    assert_equal 2, transfer.fee_transactions.count
    source_fee_tx = transfer.fee_transactions.find { |t| t.entry.account_id == accounts(:depository).id }
    dest_fee_tx = transfer.fee_transactions.find { |t| t.entry.account_id == accounts(:credit_card).id }
    assert_equal 2, source_fee_tx.entry.amount
    assert_equal 3, dest_fee_tx.entry.amount
    assert transfer.has_fees?
  end

  test "derived fee methods reflect fee transaction entry edits" do
    post transfers_url, params: {
      transfer: {
        from_account_id: accounts(:depository).id,
        to_account_id: accounts(:credit_card).id,
        date: Date.current,
        amount: 100,
        source_fee_amount: 3
      }
    }

    transfer = Transfer.order(created_at: :desc).first
    assert_equal 3, transfer.derived_source_fee_amount

    # Simulate an independent edit of the fee transaction entry
    fee_tx = transfer.fee_transactions.first
    fee_tx.entry.update!(amount: 5)

    # Derived fee should reflect the updated entry
    transfer.reload
    assert_equal 5, transfer.derived_source_fee_amount
    assert transfer.has_source_fee?
  end

  test "exchange_rate endpoint returns same_currency for matching currencies" do
    get exchange_rate_url, params: {
      from: "USD",
      to: "USD"
    }

    assert_response :success
    json_response = JSON.parse(response.body)
    assert_equal true, json_response["same_currency"]
    assert_equal 1.0, json_response["rate"]
  end

  test "soft deletes transfer" do
    assert_difference -> { Transfer.count }, -1 do
      delete transfer_url(transfers(:one))
    end
  end

  test "can create transfer with tags on both sides" do
    tag = tags(:one)

    assert_difference "Transfer.count", 1 do
      post transfers_url, params: {
        transfer: {
          from_account_id: accounts(:depository).id,
          to_account_id: accounts(:credit_card).id,
          date: Date.current,
          amount: 100,
          tag_ids: [ tag.id ]
        }
      }
    end

    transfer = Transfer.order(:created_at).last
    assert_equal [ tag.id ], transfer.outflow_transaction.tag_ids
    assert_equal [ tag.id ], transfer.inflow_transaction.tag_ids
  end

  test "can update transfer tags on both sides" do
    transfer = transfers(:one)
    tag = tags(:one)

    patch tags_transfer_url(transfer), params: { tag_ids: [ tag.id ] }, as: :json

    assert_response :success
    assert_equal [ tag.id ], transfer.outflow_transaction.reload.tag_ids
    assert_equal [ tag.id ], transfer.inflow_transaction.reload.tag_ids
    assert_equal [ tag.id ], JSON.parse(response.body)["tag_ids"]
  end

  test "update transfer tags ignores tags from other families" do
    transfer = transfers(:one)
    family_tag = tags(:one)
    other_family = Family.create!(name: "Other Family", currency: "USD")
    other_tag = other_family.tags.create!(name: "Foreign")

    patch tags_transfer_url(transfer), params: {
      tag_ids: [ family_tag.id, other_tag.id ]
    }, as: :json

    assert_response :success
    assert_equal [ family_tag.id ], transfer.outflow_transaction.reload.tag_ids
    assert_equal [ family_tag.id ], transfer.inflow_transaction.reload.tag_ids
  end

  test "can clear transfer tags" do
    transfer = transfers(:one)
    tag = tags(:one)
    transfer.outflow_transaction.update!(tag_ids: [ tag.id ])
    transfer.inflow_transaction.update!(tag_ids: [ tag.id ])

    patch tags_transfer_url(transfer), params: { tag_ids: [] }, as: :json

    assert_response :success
    assert_empty transfer.outflow_transaction.reload.tag_ids
    assert_empty transfer.inflow_transaction.reload.tag_ids
  end

  test "update tags requires annotate permission on both transfer sides" do
    # family_member: full_control on depository (outflow), read_only on credit_card (inflow)
    sign_in users(:family_member)
    transfer = transfers(:one)
    tag = tags(:one)
    original_outflow_tags = transfer.outflow_transaction.tag_ids
    original_inflow_tags = transfer.inflow_transaction.tag_ids

    patch tags_transfer_url(transfer), params: { tag_ids: [ tag.id ] }, as: :json

    assert_response :forbidden
    assert_equal I18n.t("accounts.not_authorized"), JSON.parse(response.body)["error"]
    assert_equal original_outflow_tags, transfer.outflow_transaction.reload.tag_ids
    assert_equal original_inflow_tags, transfer.inflow_transaction.reload.tag_ids
  end

  test "can add notes to transfer" do
    transfer = transfers(:one)
    assert_nil transfer.notes

    patch transfer_url(transfer), params: { transfer: { notes: "Test notes" } }

    assert_redirected_to transactions_url
    assert_equal "Transfer updated", flash[:notice]
    assert_equal "Test notes", transfer.reload.notes
  end

  test "handles rejection without FrozenError" do
    transfer = transfers(:one)

    assert_difference "Transfer.count", -1 do
      patch transfer_url(transfer), params: {
        transfer: {
          status: "rejected"
        }
      }
    end

    assert_redirected_to transactions_url
    assert_equal "Transfer updated", flash[:notice]

    # Verify the transfer was actually destroyed
    assert_raises(ActiveRecord::RecordNotFound) do
      transfer.reload
    end
  end

  test "mark_as_recurring creates a recurring transfer" do
    transfer = transfers(:one)
    family = users(:family_admin).family
    family.recurring_transactions.destroy_all

    assert_difference -> { RecurringTransaction.where(family: family).count }, +1 do
      post mark_as_recurring_transfer_url(transfer)
    end

    rt = RecurringTransaction.where(family: family).last
    assert rt.transfer?
    assert_equal transfer.outflow_transaction.entry.account, rt.account
    assert_equal transfer.inflow_transaction.entry.account, rt.destination_account
    assert rt.manual?
    assert_equal I18n.t("recurring_transactions.transfer_marked_as_recurring"), flash[:notice]
    assert_redirected_to transactions_path
  end

  test "mark_as_recurring is idempotent: second call flashes already-exists" do
    transfer = transfers(:one)
    family = users(:family_admin).family
    family.recurring_transactions.destroy_all

    post mark_as_recurring_transfer_url(transfer)
    assert_equal I18n.t("recurring_transactions.transfer_marked_as_recurring"), flash[:notice]

    assert_no_difference -> { RecurringTransaction.where(family: family).count } do
      post mark_as_recurring_transfer_url(transfer)
    end
    assert_equal I18n.t("recurring_transactions.transfer_already_exists"), flash[:alert]
  end

  test "mark_as_recurring is rejected when recurring_transactions_disabled" do
    transfer = transfers(:one)
    family = users(:family_admin).family
    family.update!(recurring_transactions_disabled: true)
    family.recurring_transactions.destroy_all

    assert_no_difference -> { RecurringTransaction.where(family: family).count } do
      post mark_as_recurring_transfer_url(transfer)
    end
    assert_equal I18n.t("recurring_transactions.transfer_feature_disabled"), flash[:alert]
  end
end