///|
pub struct Logger[S] {
  min_level : Level
  sink : S
  target : String
  timestamp : Bool
}

///|
pub fn[S] Logger::new(
  sink : S,
  min_level? : Level = Level::Info,
  target? : String = "",
) -> Logger[S] {
  { min_level, sink, target, timestamp: false }
}

///|
pub fn[S] Logger::with_target(self : Logger[S], target : String) -> Logger[S] {
  { ..self, target, }
}

///|
fn combine_targets(parent : String, child : String) -> String {
  if parent == "" {
    child
  } else if child == "" {
    parent
  } else {
    "\{parent}.\{child}"
  }
}

///|
pub fn[S] Logger::child(self : Logger[S], target : String) -> Logger[S] {
  { ..self, target: combine_targets(self.target, target) }
}

///|
pub fn[S] Logger::with_context_fields(
  self : Logger[S],
  fields : Array[Field],
) -> Logger[ContextSink[S]] {
  {
    min_level: self.min_level,
    sink: context_sink(self.sink, fields),
    target: self.target,
    timestamp: self.timestamp,
  }
}

///|
pub fn[S] Logger::bind(
  self : Logger[S],
  fields : Array[Field],
) -> Logger[ContextSink[S]] {
  self.with_context_fields(fields)
}

///|
pub fn[S] Logger::with_filter(
  self : Logger[S],
  predicate : (Record) -> Bool,
) -> Logger[FilterSink[S]] {
  {
    min_level: self.min_level,
    sink: filter_sink(self.sink, predicate),
    target: self.target,
    timestamp: self.timestamp,
  }
}

///|
pub fn[S] Logger::with_patch(
  self : Logger[S],
  patch : RecordPatch,
) -> Logger[PatchSink[S]] {
  {
    min_level: self.min_level,
    sink: patch_sink(self.sink, patch),
    target: self.target,
    timestamp: self.timestamp,
  }
}

///|
pub fn[S] Logger::with_queue(
  self : Logger[S],
  max_pending? : Int = 0,
  overflow? : QueueOverflowPolicy = QueueOverflowPolicy::DropNewest,
) -> Logger[QueuedSink[S]] {
  {
    min_level: self.min_level,
    sink: queued_sink(self.sink, max_pending~, overflow~),
    target: self.target,
    timestamp: self.timestamp,
  }
}

///|
pub fn[S] Logger::with_min_level(
  self : Logger[S],
  min_level : Level,
) -> Logger[S] {
  { ..self, min_level, }
}

///|
pub fn[S] Logger::with_timestamp(
  self : Logger[S],
  enabled? : Bool = true,
) -> Logger[S] {
  { ..self, timestamp: enabled }
}

///|
pub fn[S] Logger::is_enabled(self : Logger[S], level : Level) -> Bool {
  level.enabled(self.min_level)
}