package engine

import "fmt"

// DB code encoders/decoders.
//
// These lowercase snake_case codes are the SINGLE SOURCE OF TRUTH for the SQL CHECK constraints in
// db/migrations/0002_matching.sql. Keep two distinct representations per enum:
//   - String() — a human label for UI/explanations ("TS/SCI", "Full-Scope Poly", "Green").
//   - Code()   — the persisted DB value ("ts_sci", "full_scope", "green").
// Persisting String() instead of Code() was a real bug class (review INT-1/INT-2): "Green" and
// "TS/SCI" both violate the CHECK. The persistence layer MUST use Code()/Parse*, never String().
// TestEnumCodesMatchSQLCheckSets locks these to the migration's CHECK sets.

var clearanceLevelCodes = map[ClearanceLevel]string{
	ClearanceUnknown:      "unknown",
	ClearanceNone:         "none",
	ClearanceConfidential: "confidential",
	ClearanceSecret:       "secret",
	ClearanceTopSecret:    "top_secret",
	ClearanceTSSCI:        "ts_sci",
}

// Code returns the DB literal for the clearance level.
func (c ClearanceLevel) Code() string { return clearanceLevelCodes[c] }

// ParseClearanceLevel decodes a DB literal back to the enum, erroring on an unknown code.
func ParseClearanceLevel(code string) (ClearanceLevel, error) {
	for k, v := range clearanceLevelCodes {
		if v == code {
			return k, nil
		}
	}
	return ClearanceUnknown, fmt.Errorf("engine: invalid clearance level code %q", code)
}

var polygraphCodes = map[Polygraph]string{
	PolyNone:      "none",
	PolyCI:        "ci",
	PolyFullScope: "full_scope",
}

// Code returns the DB literal for the polygraph.
func (p Polygraph) Code() string { return polygraphCodes[p] }

// ParsePolygraph decodes a DB literal back to the enum, erroring on an unknown code.
func ParsePolygraph(code string) (Polygraph, error) {
	for k, v := range polygraphCodes {
		if v == code {
			return k, nil
		}
	}
	return PolyNone, fmt.Errorf("engine: invalid polygraph code %q", code)
}

var clearanceStatusCodes = map[ClearanceStatus]string{
	StatusUnknown:  "unknown",
	StatusActive:   "active",
	StatusExpired:  "expired",
	StatusInactive: "inactive",
}

// String returns a human label for the clearance status (was missing — review INT-2).
func (s ClearanceStatus) String() string {
	switch s {
	case StatusActive:
		return "Active"
	case StatusExpired:
		return "Expired"
	case StatusInactive:
		return "Inactive"
	default:
		return "Unknown"
	}
}

// Code returns the DB literal for the clearance status.
func (s ClearanceStatus) Code() string { return clearanceStatusCodes[s] }

// ParseClearanceStatus decodes a DB literal back to the enum, erroring on an unknown code.
func ParseClearanceStatus(code string) (ClearanceStatus, error) {
	for k, v := range clearanceStatusCodes {
		if v == code {
			return k, nil
		}
	}
	return StatusUnknown, fmt.Errorf("engine: invalid clearance status code %q", code)
}

var bandCodes = map[Band]string{
	BandRed:    "red",
	BandYellow: "yellow",
	BandGreen:  "green",
}

// Code returns the DB literal for the band.
func (b Band) Code() string { return bandCodes[b] }

// ParseBand decodes a DB literal back to the enum, erroring on an unknown code.
func ParseBand(code string) (Band, error) {
	for k, v := range bandCodes {
		if v == code {
			return k, nil
		}
	}
	return BandRed, fmt.Errorf("engine: invalid band code %q", code)
}