/**
 * Anthropic Messages API wire types.
 *
 * Hand-maintained against https://docs.anthropic.com/en/api/messages so pi-ai
 * does not depend on `@anthropic-ai/sdk` for type information. Only the shapes
 * this package actually reads or writes are modeled; fields we never touch are
 * intentionally omitted. Names mirror the SDK so call sites read the same.
 *
 * Unlike the SDK, beta fields pi-ai uses (`speed`, `context_management`,
 * `output_config.effort`/`task_budget`, `thinking.display`, cache-control
 * `scope`, tool `strict`/`eager_input_streaming`, mid-conversation `system`
 * role) are first-class here instead of being patched in via casts.
 */
import type { TokenTaskBudget } from "../types";

// ─── Cache control ──────────────────────────────────────────────────────────

/** Ephemeral prefix-cache breakpoint marker. */
export type CacheControlEphemeral = {
	type: "ephemeral";
	ttl?: "1h" | "5m";
	/** Claude Code prompt-caching-scope beta: shares the breakpoint across sessions. */
	scope?: "global";
};

// ─── Content blocks (request) ───────────────────────────────────────────────

export type Base64ImageSource = {
	type: "base64";
	media_type: "image/jpeg" | "image/png" | "image/gif" | "image/webp";
	data: string;
};

export type URLImageSource = { type: "url"; url: string };

export type FileImageSource = { type: "file"; file_id: string };

export type ImageSource = Base64ImageSource | URLImageSource | FileImageSource;

export type TextBlockParam = {
	type: "text";
	text: string;
	cache_control?: CacheControlEphemeral | null;
};

export type ImageBlockParam = {
	type: "image";
	source: ImageSource;
	cache_control?: CacheControlEphemeral | null;
};

export type ToolUseBlockParam = {
	type: "tool_use";
	id: string;
	name: string;
	input: unknown;
	cache_control?: CacheControlEphemeral | null;
};

export type ToolResultBlockParam = {
	type: "tool_result";
	tool_use_id: string;
	content?: string | Array<TextBlockParam | ImageBlockParam>;
	is_error?: boolean;
	cache_control?: CacheControlEphemeral | null;
};

export type ThinkingBlockParam = {
	type: "thinking";
	thinking: string;
	signature: string;
};

export type RedactedThinkingBlockParam = {
	type: "redacted_thinking";
	data: string;
};

export type ContentBlockParam =
	| TextBlockParam
	| ImageBlockParam
	| ToolUseBlockParam
	| ToolResultBlockParam
	| ThinkingBlockParam
	| RedactedThinkingBlockParam;

/**
 * A single conversation turn.
 *
 * `system` is the Opus 4.8+ mid-conversation system role
 * (`mid-conversation-system-2026-04-07` beta); the public API otherwise only
 * accepts `user` / `assistant`.
 */
export type MessageParam = {
	role: "user" | "assistant" | "system";
	content: string | ContentBlockParam[];
};

// ─── Tools ──────────────────────────────────────────────────────────────────

export type ToolInputSchema = {
	type: "object";
	properties?: unknown | null;
	required?: string[] | null;
	[k: string]: unknown;
};

export type Tool = {
	name: string;
	description?: string;
	input_schema: ToolInputSchema;
	cache_control?: CacheControlEphemeral | null;
	/** Structured-outputs beta: enforce the schema as a strict grammar. */
	strict?: boolean;
	/** Fine-grained tool streaming beta: stream tool input as it is generated. */
	eager_input_streaming?: boolean;
};

export type ToolChoiceAuto = { type: "auto"; disable_parallel_tool_use?: boolean };
export type ToolChoiceAny = { type: "any"; disable_parallel_tool_use?: boolean };
export type ToolChoiceTool = { type: "tool"; name: string; disable_parallel_tool_use?: boolean };
export type ToolChoiceNone = { type: "none" };

export type ToolChoice = ToolChoiceAuto | ToolChoiceAny | ToolChoiceTool | ToolChoiceNone;

// ─── Request ────────────────────────────────────────────────────────────────

export type Metadata = { user_id?: string | null };

export type ThinkingConfigEnabled = {
	type: "enabled";
	budget_tokens: number;
	/** Opus 4.7+ reasoning display mode. */
	display?: "summarized" | "omitted";
};

export type ThinkingConfigDisabled = { type: "disabled" };

export type ThinkingConfigAdaptive = {
	type: "adaptive";
	/** Opus 4.7+ reasoning display mode. */
	display?: "summarized" | "omitted";
};

export type ThinkingConfigParam = ThinkingConfigEnabled | ThinkingConfigDisabled | ThinkingConfigAdaptive;

export type OutputConfig = {
	/** Adaptive-thinking effort level (effort beta). */
	effort?: "low" | "medium" | "high" | "xhigh" | "max" | null;
	/** Task-budgets beta. */
	task_budget?: TokenTaskBudget | null;
};

/** Claude Code context-management beta payload. */
export type ContextManagement = {
	edits: Array<{ type: "clear_thinking_20251015"; keep: "all" }>;
};

export type MessageCreateParams = {
	model: string;
	messages: MessageParam[];
	max_tokens: number;
	system?: string | TextBlockParam[];
	temperature?: number;
	top_p?: number;
	top_k?: number;
	stop_sequences?: string[];
	stream?: boolean;
	tools?: Tool[];
	tool_choice?: ToolChoice;
	metadata?: Metadata;
	thinking?: ThinkingConfigParam;
	output_config?: OutputConfig;
	/** Fast-mode beta: realization of priority service tier. */
	speed?: "fast";
	/** Claude Code context-management beta. */
	context_management?: ContextManagement;
};

export type MessageCreateParamsStreaming = MessageCreateParams & { stream: true };

// ─── Response / usage ───────────────────────────────────────────────────────

export type StopReason =
	| "end_turn"
	| "max_tokens"
	| "stop_sequence"
	| "tool_use"
	| "pause_turn"
	| "refusal"
	| "sensitive"
	| "model_context_window_exceeded";

export type CacheCreation = {
	ephemeral_5m_input_tokens?: number | null;
	ephemeral_1h_input_tokens?: number | null;
};

export type ServerToolUsage = {
	web_search_requests?: number | null;
	web_fetch_requests?: number | null;
};

export type Usage = {
	input_tokens?: number | null;
	output_tokens?: number | null;
	cache_read_input_tokens?: number | null;
	cache_creation_input_tokens?: number | null;
	cache_creation?: CacheCreation | null;
	server_tool_use?: ServerToolUsage | null;
};

/** The `message` envelope carried by `message_start`. */
export type ResponseMessage = {
	id: string;
	type?: "message";
	role?: "assistant";
	model?: string;
	content?: unknown[];
	stop_reason?: StopReason | null;
	stop_sequence?: string | null;
	usage: Usage;
};

// ─── Stream events ──────────────────────────────────────────────────────────

/** `content_block` payload carried by `content_block_start`. */
export type ResponseContentBlock =
	| { type: "text"; text: string }
	| { type: "thinking"; thinking: string; signature?: string }
	| { type: "redacted_thinking"; data: string }
	| { type: "tool_use"; id: string; name: string; input?: Record<string, unknown> | null };

export type ContentBlockDelta =
	| { type: "text_delta"; text: string }
	| { type: "input_json_delta"; partial_json: string }
	| { type: "thinking_delta"; thinking: string }
	| { type: "signature_delta"; signature: string };

export type StopDetails = {
	type: string;
	category?: string | null;
	explanation?: string | null;
};

export type MessageDelta = {
	stop_reason?: StopReason | null;
	stop_sequence?: string | null;
	stop_details?: StopDetails | null;
};

export type RawMessageStartEvent = { type: "message_start"; message: ResponseMessage };
export type RawContentBlockStartEvent = {
	type: "content_block_start";
	index: number;
	content_block: ResponseContentBlock;
};
export type RawContentBlockDeltaEvent = { type: "content_block_delta"; index: number; delta: ContentBlockDelta };
export type RawContentBlockStopEvent = { type: "content_block_stop"; index: number };
export type RawMessageDeltaEvent = { type: "message_delta"; delta: MessageDelta; usage: Usage };
export type RawMessageStopEvent = { type: "message_stop" };

export type RawMessageStreamEvent =
	| RawMessageStartEvent
	| RawContentBlockStartEvent
	| RawContentBlockDeltaEvent
	| RawContentBlockStopEvent
	| RawMessageDeltaEvent
	| RawMessageStopEvent;