emv

type AFL struct {
	Entries      []AFLEntry   `json:"entries"`
	ReadRecords  []ReadRecord `json:"read_records"`
	TotalRecords int          `json:"total_records"`
}

type AFLEntry struct {
	SFI         int   `json:"sfi"`
	FirstRecord int   `json:"first_record"`
	LastRecord  int   `json:"last_record"`
	ODARecords  int   `json:"oda_records"`
	Records     []int `json:"records"`
}

type AIP struct {
	Raw   string `json:"raw"`   // the 2 bytes, hex
	Byte1 string `json:"byte1"` // 0xNN
	Byte2 string `json:"byte2"` // 0xNN

	// Byte-1 capability bits (EMV Book 3 Annex C1).
	SDA                    bool `json:"sda_supported"`                        // bit 7 (0x40)
	DDA                    bool `json:"dda_supported"`                        // bit 6 (0x20)
	CardholderVerification bool `json:"cardholder_verification_supported"`    // bit 5 (0x10)
	TerminalRiskManagement bool `json:"terminal_risk_management_to_perform"`  // bit 4 (0x08)
	IssuerAuthentication   bool `json:"issuer_authentication_supported"`      // bit 3 (0x04)
	OnDeviceCVM            bool `json:"on_device_cardholder_verif_supported"` // bit 2 (0x02), EMV 4.3+
	CDA                    bool `json:"cda_supported"`                        // bit 1 (0x01)

	// Capabilities is the human-readable list of the set byte-1 bits, in
	// bit order, for a quick read of what the card advertises.
	Capabilities []string `json:"capabilities"`

	// OfflineDataAuthentication summarises the SDA/DDA/CDA story — the
	// single most security-relevant takeaway from an AIP.
	OfflineDataAuthentication string `json:"offline_data_authentication"`

	Notes []string `json:"notes,omitempty"`
}

type CVMList struct {
	AmountX uint32    `json:"amount_x"`
	AmountY uint32    `json:"amount_y"`
	Rules   []CVMRule `json:"rules"`
	Notes   []string  `json:"notes,omitempty"`
}

type CVMResults struct {
	Raw string `json:"raw"` // the 3 bytes, hex

	CVMPerformedByte        string `json:"cvm_performed_byte"`
	CVMCode                 int    `json:"cvm_code"` // low 6 bits
	CVMPerformed            string `json:"cvm_performed"`
	ApplyNextIfUnsuccessful bool   `json:"apply_next_if_unsuccessful"` // bit 7 (0x40)

	CVMConditionByte string `json:"cvm_condition_byte"`
	CVMCondition     string `json:"cvm_condition"`

	ResultByte string `json:"result_byte"`
	Result     string `json:"result"` // Unknown / Failed / Successful

	Notes []string `json:"notes,omitempty"`
}

type CVMRule struct {
	Raw                     string `json:"raw"` // the 2 bytes, hex
	MethodByte              string `json:"method_byte"`
	MethodCode              int    `json:"method_code"` // low 6 bits
	Method                  string `json:"method"`
	ApplyNextIfUnsuccessful bool   `json:"apply_next_if_unsuccessful"` // bit 7 (0x40): else fail CVM
	ConditionByte           string `json:"condition_byte"`
	Condition               string `json:"condition"`
}

type DOL struct {
	Entries     []DOLEntry `json:"entries"`
	Count       int        `json:"count"`
	TotalLength int        `json:"total_length"`
}

type DOLEntry struct {
	Tag    uint32 `json:"tag"`
	TagHex string `json:"tag_hex"`
	Name   string `json:"name,omitempty"`
	Length int    `json:"length"`
}

type Magstripe struct {
	Track1 *Track1  `json:"track1,omitempty"`
	Track2 *Track2  `json:"track2,omitempty"`
	Notes  []string `json:"notes,omitempty"`
}

type ReadRecord struct {
	SFI    int `json:"sfi"`
	Record int `json:"record"`
}

type TLV struct {
	// Tag is the BER tag as a uint32 — the encoded big-endian bytes
	// of the tag identifier. Single-byte tags use the low byte;
	// multi-byte tags pack into successively higher bytes (so 0x9F02
	// is the most common Amount Authorised tag, 0x5F2A is the
	// Transaction Currency Code, etc.). Stored as uint32 so the
	// tag-name lookup map can key on it without a string conversion.
	Tag uint32 `json:"tag"`
	// TagHex is the operator-facing rendering of Tag — always
	// uppercase, no 0x prefix, no leading zeros. Matches the format
	// every EMV book / forum post uses ("9F02", "5F2A").
	TagHex string `json:"tag_hex"`
	// Name is the canonical EMV name for the tag, or "" when the
	// tag isn't in the curated lookup table.
	Name string `json:"name,omitempty"`
	// Constructed reports whether the value bytes contain nested
	// TLVs (per BER class+P/C bit). When true, Children holds the
	// parsed sub-tree and Value is the raw bytes (kept for callers
	// that want to re-emit the original structure).
	Constructed bool   `json:"constructed"`
	Value       []byte `json:"value,omitempty"`
	// ValueHex is the operator-facing hex rendering of Value.
	// Convenient for JSON output without forcing every caller to
	// re-encode.
	ValueHex string `json:"value_hex,omitempty"`
	// Children is non-nil iff Constructed is true. May be empty
	// when a constructed tag's body is zero-length (legal per the
	// spec, occasionally seen in templated responses).
	Children []TLV `json:"children,omitempty"`
}

type TSI struct {
	Raw   string   `json:"raw"`   // the 2 bytes, hex
	Bytes []string `json:"bytes"` // each byte, 0xNN

	// FunctionsPerformed lists the set bits — each a function the terminal
	// performed — in bit order (byte 1, high to low).
	FunctionsPerformed []string `json:"functions_performed"`

	// NonePerformed reports an all-zero TSI: the terminal recorded no
	// completed function (e.g. a transaction aborted very early).
	NonePerformed bool `json:"none_performed"`

	Notes []string `json:"notes,omitempty"`
}

type TVR struct {
	Raw   string   `json:"raw"`   // the 5 bytes, hex
	Bytes []string `json:"bytes"` // each byte, 0xNN

	// Clean reports that no exception bit is set across all 5 bytes — the
	// terminal flagged nothing.
	Clean bool `json:"clean"`

	// Each group lists the set bits for one functional byte (omitted when
	// that byte is zero). Grouped per EMV Book 3 Annex C5's own byte layout.
	OfflineDataAuthentication []string `json:"offline_data_authentication,omitempty"` // byte 1
	ApplicationUsage          []string `json:"application_usage,omitempty"`           // byte 2
	CardholderVerification    []string `json:"cardholder_verification,omitempty"`     // byte 3
	TerminalRiskManagement    []string `json:"terminal_risk_management,omitempty"`    // byte 4
	IssuerScriptProcessing    []string `json:"issuer_script_processing,omitempty"`    // byte 5

	// Indications is the flat list of every set defined bit, in byte/bit
	// order — a one-glance read of everything the terminal flagged.
	Indications []string `json:"indications"`

	Notes []string `json:"notes,omitempty"`
}

type Track1 struct {
	FormatCode         string   `json:"format_code"` // 'B' = financial/bank
	PAN                string   `json:"pan"`
	PANMasked          string   `json:"pan_masked"`
	Name               string   `json:"name,omitempty"`
	Surname            string   `json:"surname,omitempty"`
	GivenName          string   `json:"given_name,omitempty"`
	Expiry             string   `json:"expiry,omitempty"`       // raw YYMM
	ExpiryFormatted    string   `json:"expiry_mm_yy,omitempty"` // MM/YY
	ServiceCode        string   `json:"service_code,omitempty"`
	ServiceCodeMeaning string   `json:"service_code_meaning,omitempty"`
	Discretionary      string   `json:"discretionary_data,omitempty"`
	LuhnValid          bool     `json:"luhn_valid"`
	LRC                string   `json:"lrc,omitempty"` // trailing redundancy char, surfaced raw (not validated)
	Notes              []string `json:"notes,omitempty"`
}

type Track2 struct {
	PAN                string   `json:"pan"`
	PANMasked          string   `json:"pan_masked"`
	Expiry             string   `json:"expiry"`       // raw YYMM as encoded
	ExpiryFormatted    string   `json:"expiry_mm_yy"` // MM/YY
	ServiceCode        string   `json:"service_code"` // 3 digits
	ServiceCodeMeaning string   `json:"service_code_meaning,omitempty"`
	Discretionary      string   `json:"discretionary_data,omitempty"`
	LuhnValid          bool     `json:"luhn_valid"`
	Notes              []string `json:"notes,omitempty"`
}