# `Bandera.Store.Persistent.Redis.Serializer`

Pure mapping between `Bandera.Gate`s and Redis hash `{field, value}` pairs.

The hash field is the gate id (`Bandera.Gate.id/1`), so both percentage gate
types share the `"percentage"` field (one percentage gate per flag — an HSET
overwrites it). The value encodes `"true"`/`"false"` for boolean/actor/group, or
`"time/<ratio>"`/`"actors/<ratio>"` for percentage gates.

Flag names read back are converted to atoms via `String.to_atom/1` (supporting
listing flags created in a prior VM session). Flag names must therefore be a
bounded, developer-defined set — never untrusted user input.

# `deserialize_flag`

```elixir
@spec deserialize_flag(atom() | String.t(), [String.t()]) :: Bandera.Flag.t()
```

Rebuilds a `Bandera.Flag` from a flat `HGETALL` reply (alternating field/value
entries).

The flag name is converted to an atom, so it must be a bounded, developer-defined
value — never untrusted input.

## Examples

    iex> flag = Bandera.Store.Persistent.Redis.Serializer.deserialize_flag(:my_flag, ["boolean", "true"])
    iex> flag.name
    :my_flag
    iex> flag.gates
    [%Bandera.Gate{type: :boolean, for: nil, enabled: true}]

# `field`

```elixir
@spec field(Bandera.Gate.t()) :: String.t()
```

Returns the Redis hash field for a gate (its id) — the hash key used to delete it.

## Examples

    iex> Bandera.Store.Persistent.Redis.Serializer.field(Bandera.Gate.new(:group, :beta, true))
    "group/beta"

# `serialize`

```elixir
@spec serialize(Bandera.Gate.t()) :: {String.t(), String.t()}
```

Serializes a gate to the `{field, value}` pair stored in the flag's Redis hash.

The field is the gate id (so the percentage slot is shared); the value encodes the
ratio for percentage gates and the boolean otherwise.

## Examples

    iex> Bandera.Store.Persistent.Redis.Serializer.serialize(Bandera.Gate.new(:boolean, true))
    {"boolean", "true"}

    iex> Bandera.Store.Persistent.Redis.Serializer.serialize(Bandera.Gate.new(:actor, "u1", true))
    {"actor/u1", "true"}

    iex> Bandera.Store.Persistent.Redis.Serializer.serialize(Bandera.Gate.new(:percentage_of_time, 0.5))
    {"percentage", "time/0.5"}

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*Consult [api-reference.md](api-reference.md) for complete listing*