import type { AgentToolResult } from "@oh-my-pi/pi-agent-core";
import type { ImageContent, TextContent } from "@oh-my-pi/pi-ai";
import type { OutputSummary, TruncationResult } from "@oh-my-pi/pi-tui/tools/streaming-output";
import type { MinimizedMeta, OutputMeta } from "@oh-my-pi/pi-tui/tools/output-meta";
import type { LimitsInput, TruncationMetaInput, TruncationSummaryOptions, TruncationTextOptions } from "./output-meta";
import { outputMeta } from "./output-meta";

type ToolContent = Array<TextContent | ImageContent>;

type DetailsWithMeta = { meta?: OutputMeta };

export class ToolResultBuilder<TDetails extends DetailsWithMeta> {
	#details: TDetails;
	#meta = outputMeta();
	#content: ToolContent = [];
	#isError = false;
	#useless = false;

	constructor(details?: TDetails) {
		this.#details = details ?? ({} as TDetails);
	}

	text(text: string): this {
		this.#content = [{ type: "text", text }];
		return this;
	}

	content(content: ToolContent): this {
		this.#content = content;
		return this;
	}

	truncation(result: TruncationResult, options: TruncationMetaInput): this {
		this.#meta.truncation(result, options);
		return this;
	}

	truncationFromSummary(summary: OutputSummary, options: TruncationSummaryOptions): this {
		this.#meta.truncationFromSummary(summary, options);
		return this;
	}

	truncationFromText(text: string, options: TruncationTextOptions): this {
		this.#meta.truncationFromText(text, options);
		return this;
	}

	limits(limits: LimitsInput): this {
		this.#meta.limits(limits);
		return this;
	}

	sourceUrl(value: string): this {
		this.#meta.sourceUrl(value);
		return this;
	}

	sourcePath(value: string): this {
		this.#meta.sourcePath(value);
		return this;
	}

	sourceInternal(value: string): this {
		this.#meta.sourceInternal(value);
		return this;
	}

	/** Mark the result as a bounded page of a file its source re-reads with line selectors. */
	pagedSource(): this {
		this.#meta.pagedSource();
		return this;
	}

	diagnostics(summary: string, messages: string[]): this {
		this.#meta.diagnostics(summary, messages);
		return this;
	}

	/** Record the bash minimizer's rewrite of this output, when there was one. */
	minimized(value: MinimizedMeta | undefined): this {
		this.#meta.minimized(value);
		return this;
	}

	/** Flag the result as a non-throwing failure (agent-loop surfaces it as a tool error). */
	error(value = true): this {
		this.#isError = value;
		return this;
	}

	/** Marks the result contextually useless — compaction may elide it once consumed. */
	useless(value = true): this {
		this.#useless = value;
		return this;
	}

	done(): AgentToolResult<TDetails> {
		const meta = this.#meta.get();
		if (meta) {
			this.#details.meta = meta;
		}
		const hasDetails = Object.entries(this.#details).some(([, value]) => value !== undefined);

		return {
			content: this.#content,
			details: hasDetails ? this.#details : undefined,
			...(this.#isError ? { isError: true } : {}),
			...(this.#useless && !this.#isError ? { useless: true } : {}),
		};
	}
}

export function toolResult<TDetails extends DetailsWithMeta>(details?: TDetails): ToolResultBuilder<TDetails> {
	return new ToolResultBuilder(details);
}