package storage

// StationNeighbor represents a neighboring station that can be used as a fallback
// when the main station is closed. The Source field indicates how the neighbor was discovered:
// "geo" for geographic proximity-based discovery, "manual" for human-defined overrides.
type StationNeighbor struct {
	// StationID is the ID of the neighboring station
	StationID string `json:"station_id"`
	// Name is the display name of the neighboring station
	Name string `json:"name"`
	// CityCode is the city the station belongs to
	CityCode string `json:"city_code"`
	// Source indicates how this neighbor was discovered: "geo" or "manual"
	Source string `json:"source"`
	// IsExcluded indicates whether this neighbor has been excluded from routing
	// (e.g., due to closure, maintenance, or other reasons)
	IsExcluded bool `json:"is_excluded"`
}

// StationNeighborsTable manages station neighbor records in the database.
// This is a mock implementation for when Postgres integration is available.
type StationNeighborsTable struct {
	// In a full implementation, this would be a database connection/pool
	// For now, we use in-memory maps per city code
	neighbors map[string][]StationNeighbor
}

// NewStationNeighborsTable creates a new StationNeighborsTable instance.
func NewStationNeighborsTable() *StationNeighborsTable {
	return &StationNeighborsTable{
		neighbors: make(map[string][]StationNeighbor),
	}
}

// Add adds a station neighbor to the table for the given city code.
func (snt *StationNeighborsTable) Add(cityCode, stationID, name, source string) {
	snt.neighbors[cityCode] = append(snt.neighbors[cityCode], StationNeighbor{
		StationID: stationID,
		Name:      name,
		CityCode:  cityCode,
		Source:    source,
	})
}

// GetByCity returns all neighbors for a given city code.
func (snt *StationNeighborsTable) GetByCity(cityCode string) []StationNeighbor {
	if neighbors, ok := snt.neighbors[cityCode]; ok {
		return neighbors
	}
	return nil
}

// MarkExcluded marks a neighbor as excluded for the given station ID and city code.
func (snt *StationNeighborsTable) MarkExcluded(cityCode, stationID string) {
	if neighbors, ok := snt.neighbors[cityCode]; ok {
		for i := range neighbors {
			if neighbors[i].StationID == stationID {
				neighbors[i].IsExcluded = true
				return
			}
		}
	}
}

// GetNonExcluded returns non-excluded neighbors for a given city code.
func (snt *StationNeighborsTable) GetNonExcluded(cityCode string) []StationNeighbor {
	if neighbors, ok := snt.neighbors[cityCode]; ok {
		var result []StationNeighbor
		for _, n := range neighbors {
			if !n.IsExcluded {
				result = append(result, n)
			}
		}
		return result
	}
	return nil
}