{
  "format": 1,
  "function": "propose_allocation",
  "cases": [
    {
      "name": "owing X (-30000, oldest owing) and Y (-20000), owed in Z (+10000): 40000 gives X 30000, Y 10000",
      "input": {
        "amount_ore": 40000,
        "accounts": [
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 },
          { "account_id": "Y", "created_at": "2025-02-01T00:00:00.000Z", "archived": false, "payer_net_ore": -20000 },
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 30000 }, { "account_id": "Y", "amount_ore": 10000 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "same accounts, 50000 = exactly the total debt: no excess",
      "input": {
        "amount_ore": 50000,
        "accounts": [
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 },
          { "account_id": "Y", "created_at": "2025-02-01T00:00:00.000Z", "archived": false, "payer_net_ore": -20000 },
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 30000 }, { "account_id": "Y", "amount_ore": 20000 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "same accounts, 60000: excess 10000 added to the last owing account Y, over-settled [Y]",
      "input": {
        "amount_ore": 60000,
        "accounts": [
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 },
          { "account_id": "Y", "created_at": "2025-02-01T00:00:00.000Z", "archived": false, "payer_net_ore": -20000 },
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 30000 }, { "account_id": "Y", "amount_ore": 30000 } ], "excess_ore": 10000, "over_settled_account_ids": ["Y"] } }
    },
    {
      "name": "same accounts, 20000 is less than the first debt: only X",
      "input": {
        "amount_ore": 20000,
        "accounts": [
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 },
          { "account_id": "Y", "created_at": "2025-02-01T00:00:00.000Z", "archived": false, "payer_net_ore": -20000 },
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 20000 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "input order does not matter: accounts listed newest first",
      "input": {
        "amount_ore": 40000,
        "accounts": [
          { "account_id": "Y", "created_at": "2025-02-01T00:00:00.000Z", "archived": false, "payer_net_ore": -20000 },
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 },
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 30000 }, { "account_id": "Y", "amount_ore": 10000 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "no owing accounts: 5000 with only Z (owed) goes to Z, over-settled [Z]",
      "input": {
        "amount_ore": 5000,
        "accounts": [ { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 } ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "Z", "amount_ore": 5000 } ], "excess_ore": 5000, "over_settled_account_ids": ["Z"] } }
    },
    {
      "name": "no owing accounts: a net of exactly 0 is not owing; target is the oldest non-archived account",
      "input": {
        "amount_ore": 700,
        "accounts": [
          { "account_id": "A", "created_at": "2024-01-01T00:00:00.000Z", "archived": true, "payer_net_ore": 0 },
          { "account_id": "B", "created_at": "2024-06-01T00:00:00.000Z", "archived": false, "payer_net_ore": 500 },
          { "account_id": "C", "created_at": "2024-03-01T00:00:00.000Z", "archived": false, "payer_net_ore": 0 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "C", "amount_ore": 700 } ], "excess_ore": 700, "over_settled_account_ids": ["C"] } }
    },
    {
      "name": "all accounts archived and none owing: the oldest account",
      "input": {
        "amount_ore": 1200,
        "accounts": [
          { "account_id": "P", "created_at": "2025-05-01T00:00:00.000Z", "archived": true, "payer_net_ore": 0 },
          { "account_id": "Q", "created_at": "2025-03-01T00:00:00.000Z", "archived": true, "payer_net_ore": 300 },
          { "account_id": "R", "created_at": "2025-04-01T00:00:00.000Z", "archived": true, "payer_net_ore": 0 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "Q", "amount_ore": 1200 } ], "excess_ore": 1200, "over_settled_account_ids": ["Q"] } }
    },
    {
      "name": "archived owing accounts are still settled (archived never affects money)",
      "input": {
        "amount_ore": 1500,
        "accounts": [
          { "account_id": "old", "created_at": "2024-01-01T00:00:00.000Z", "archived": true, "payer_net_ore": -1000 },
          { "account_id": "new", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -1000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "old", "amount_ore": 1000 }, { "account_id": "new", "amount_ore": 500 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "equal created_at among owing accounts: ordered by id ascending",
      "input": {
        "amount_ore": 1500,
        "accounts": [
          { "account_id": "q", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -1000 },
          { "account_id": "p", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -1000 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "p", "amount_ore": 1000 }, { "account_id": "q", "amount_ore": 500 } ], "excess_ore": 0, "over_settled_account_ids": [] } }
    },
    {
      "name": "equal created_at with no owing account: target chosen by id ascending",
      "input": {
        "amount_ore": 100,
        "accounts": [
          { "account_id": "n", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": 0 },
          { "account_id": "m", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": 50 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "m", "amount_ore": 100 } ], "excess_ore": 100, "over_settled_account_ids": ["m"] } }
    },
    {
      "name": "single owing account, amount above its debt: excess to it",
      "input": {
        "amount_ore": 1000,
        "accounts": [
          { "account_id": "Z", "created_at": "2024-12-01T00:00:00.000Z", "archived": false, "payer_net_ore": 10000 },
          { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -1 }
        ]
      },
      "expected": { "ok": { "allocations": [ { "account_id": "X", "amount_ore": 1000 } ], "excess_ore": 999, "over_settled_account_ids": ["X"] } }
    },
    {
      "name": "no accounts",
      "input": { "amount_ore": 1000, "accounts": [] },
      "expected": { "error": "no_accounts" }
    },
    {
      "name": "amount 0",
      "input": {
        "amount_ore": 0,
        "accounts": [ { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 } ]
      },
      "expected": { "error": "amount_out_of_range" }
    },
    {
      "name": "amount 1 000 000 001",
      "input": {
        "amount_ore": 1000000001,
        "accounts": [ { "account_id": "X", "created_at": "2025-01-01T00:00:00.000Z", "archived": false, "payer_net_ore": -30000 } ]
      },
      "expected": { "error": "amount_out_of_range" }
    },
    {
      "name": "error order: amount checked before no accounts",
      "input": { "amount_ore": 0, "accounts": [] },
      "expected": { "error": "amount_out_of_range" }
    }
  ]
}