pub(open) trait Dialect {
  fn id(Self) -> String
  fn model(Self) -> String = _
  fn lower_context(Self, LlmContext) -> Json
  fn lift_message(Self, Json) -> ContextMessage raise DialectError
  fn stream_init(Self) -> StreamState = _
  fn stream_feed(Self, StreamState, chunk~ : String) -> (StreamState, Array[StreamEvent]) raise DialectError = _
  fn stream_finish(Self, StreamState) -> ContextMessage raise DialectError = _
}

pub(open) trait LlmTransport {
  fn send(Self, handle~ : String, target~ : String, body~ : Json, headers~ : Map[String, String], on_chunk~ : (String) -> Unit, on_done~ : () -> Unit, on_error~ : (String) -> Unit) -> Unit
  fn abort(Self, handle~ : String) -> Unit = _
}

pub(all) suberror DialectError {
  MalformedReply(String)
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct ApiSpec {
  id : String
  make : (ModelInfo) -> &Dialect
  caps : (String) -> ModelInfo
}

pub(all) enum AssistantBlock {
  AssistantText(text~ : String, signature~ : String?)
  Thinking(text~ : String, signature~ : String?, redacted~ : Bool)
  ToolCall(id~ : String, name~ : String, arguments~ : Json, signature~ : String?)
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum AuthStyle {
  BearerHeader
  KeyHeader(String)
  KeyQuery(String)
  NoAuth
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum CacheRetention {
  NoCache
  ShortCache
  LongCache
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum ContextMessage {
  UserMsg(content~ : Array[UserBlock])
  AssistantMsg(content~ : Array[AssistantBlock], stop~ : StopReason, model~ : String, response_id~ : String?, usage~ : Usage?, error~ : String?)
  ToolResultMsg(tool_call_id~ : String, tool_name~ : String, content~ : Array[UserBlock], is_error~ : Bool)
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct Cost {
  input : Double
  output : Double
  cache_read : Double
  cache_write : Double
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct LlmContext {
  system : String?
  messages : Array[ContextMessage]
  tools : Array[ToolDecl]
  params : LlmParams
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct LlmParams {
  effort : ThinkingLevel?
  pro_mode : Bool
  reasoning_context : ReasoningContext?
  reasoning_summary : Bool
  max_output_tokens : Int?
  cache_key : String?
  cache_retention : CacheRetention
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum Modality {
  TextIn
  ImageIn
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct ModelInfo {
  id : String
  api : String?
  reasoning : Bool
  thinking_levels : Array[(ThinkingLevel, String)]
  supports_pro_mode : Bool
  reasoning_contexts : Array[ReasoningContext]
  input : Array[Modality]
  context_window : Int
  max_output_tokens : Int?
  cost : Cost?
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct ProviderSpec {
  id : String
  name : String
  api : String
  endpoint : String
  auth : AuthStyle
  key_env : String
  model_env : String
  default_model : String
  models : Array[ModelInfo]
  headers : Map[String, String]
  telemetry_name : String
  server_address : String
} derive(
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum ReasoningContext {
  AutoContext
  CurrentTurn
  AllTurns
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct Registry {
  apis : Map[String, ApiSpec]
  providers : Array[ProviderSpec]
}

pub(all) struct RelayTransport {
  post : (String, String, String, (String) -> Unit, (String) -> Unit) -> Unit
  stop : (String) -> Unit
}

pub(all) enum StopReason {
  EndTurn
  MaxTokens
  ToolUse
  Errored
  Aborted
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum StreamEvent {
  Start(model~ : String)
  TextStart(content_index~ : Int)
  TextDelta(content_index~ : Int, delta~ : String)
  TextEnd(content_index~ : Int)
  ThinkingStart(content_index~ : Int)
  ThinkingDelta(content_index~ : Int, delta~ : String)
  ThinkingEnd(content_index~ : Int)
  ToolCallStart(content_index~ : Int, id~ : String, name~ : String)
  ToolCallDelta(content_index~ : Int, delta~ : String)
  ToolCallEnd(content_index~ : Int)
  Done(stop~ : StopReason, usage~ : Usage?)
  Error(message~ : String)
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct StreamState {
  chunks : Array[String]
} derive(
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum ThinkingLevel {
  Off
  Minimal
  Low
  Medium
  High
  XHigh
  Max
} derive(Compare, Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct ToolDecl {
  name : String
  description : String
  input_schema : Json
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) struct Usage {
  input : Int
  output : Int
  cache_read : Int
  cache_write : Int
} derive(Eq, ToJson, 
@moonbitlang/core/debug.Debug
Debug)

pub(all) enum UserBlock {
  UserText(String)
  UserImage(media_type~ : String, data~ : Bytes)
} derive(ToJson, 
@moonbitlang/core/debug.Debug
Debug)

fn api_error(reply : Json, model~ : String) -> ContextMessage?

fn reply_identity(reply : Json, fallback~ : String) -> (String, String?)

fn split_label(label : String) -> (String, String)

fn user_text(blocks : Array[UserBlock]) -> String