## Purpose

Define the TradeItem extraction schema, ExtractionResult wrapper, and mapping rules for converting sales email content into structured trade data.

## Requirements

### Requirement: TradeItem schema

The system SHALL define a `TradeItem` class with the following fields representing a single trade leg extracted from a sales email:
- `valuedate` (string, dd/MM/yyyy format)
- `counterparty` (string, full legal name as it appears in the email)
- `legal_entity` (string, nullable — populated after counterparty disambiguation via lookup tool)
- `trade_id` (long, Murex trade identifier)
- `display_ccy` (string, ISO currency code e.g. "GBP", "USD")
- `pv` (double, present value)
- `breakclause` (string, "Y" or "N")

JSON serialization SHALL use snake_case property names via `[JsonPropertyName]` attributes.

#### Scenario: All fields populated

- **WHEN** the extraction agent produces a TradeItem with all fields
- **THEN** the JSON output contains all seven fields with snake_case keys and correct types

#### Scenario: Legal entity null before disambiguation

- **WHEN** the extraction agent produces a TradeItem before counterparty lookup
- **THEN** the `legal_entity` field is null and all other fields are populated

### Requirement: ExtractionResult wrapper

The system SHALL define an `ExtractionResult` class containing a `List<TradeItem> Items` property. All extraction output from a single email SHALL be wrapped in this object.

#### Scenario: Single email with multiple trade legs

- **WHEN** an email contains two swaps with two legs each (4 trades total)
- **THEN** the ExtractionResult contains an `items` array with 4 TradeItem objects

#### Scenario: JSON output structure

- **WHEN** the ExtractionResult is serialized to JSON
- **THEN** the output has the shape `{"items": [{"valuedate": "...", ...}, ...]}`

### Requirement: Extraction mapping rules

The extraction agent SHALL follow these mapping rules when converting email content to TradeItems:
- Each swap leg (identified by a unique Murex trade ID) becomes a separate TradeItem
- The `valuedate` SHALL be parsed from date references in the email (e.g., "OB 27/11/2025") and formatted as dd/MM/yyyy
- The `counterparty` SHALL be the full legal entity name as stated in the email prose
- The `display_ccy` SHALL be derived from the currency symbol or code in the email (e.g., "£" or "PV (£)" → "GBP")
- The `breakclause` SHALL default to "N" if not explicitly mentioned in the email
- The `pv` SHALL be the numeric present value without formatting (no commas, no currency symbols)

#### Scenario: Flatten multi-leg swap into individual items

- **WHEN** the email contains a swap with Coupon Leg (Murex 79353083) and APD leg (Murex 79353084)
- **THEN** the output contains two separate TradeItems, one per Murex ID

#### Scenario: Currency symbol to ISO code mapping

- **WHEN** the email shows PV values in "PV (£)" column
- **THEN** the `display_ccy` field is set to "GBP"

#### Scenario: Default breakclause

- **WHEN** the email does not mention break clauses
- **THEN** all TradeItems have `breakclause` set to "N"