/**
 * pi-loop iteration-prompt builder (pure). The stable molde re-injected each
 * iteration (autonomous objective vs verbatim task; fixed vs dynamic cadence
 * guidance). Extracted from index.ts with the body verbatim; the only change is
 * the parameter type, decoupled from LoopState into a structural input so this
 * leaf has no cycle back to index.ts. Depth-one sibling imported via "./prompt.js".
 */

import { CONFIG_DIR_NAME } from "@earendil-works/pi-coding-agent";
import { formatInterval } from "./interval.js";

/** Structural subset of LoopState that makeLoopIterationPrompt reads. A full LoopState satisfies it. */
export interface LoopIterationPromptInput {
	loopId: string;
	task: string;
	mode: "dynamic" | "fixed";
	intervalMs?: number;
	iteration: number;
	maxIterations: number;
	lastReason?: string;
	autonomous?: boolean;
	ultracode?: boolean;
}

/** Molde estable de prompt de iteración (cf. makeWorkflowWakePrompt). */
export function makeLoopIterationPrompt(loop: LoopIterationPromptInput): string {
	const lines: string[] = [];
	lines.push(`You are running a /loop iteration (loop ${loop.loopId}).`);
	lines.push("");
	if (loop.autonomous) {
		// Autonomous mode (P2): no conventional user task. The "task" field holds the
		// recurring OBJECTIVE; the re-injected text is this sentinel, not a user message.
		lines.push("AUTONOMOUS LOOP (no interactive user this turn).");
		lines.push("This iteration was generated by the /loop extension to pursue a recurring objective:");
		lines.push("");
		lines.push("OBJECTIVE (verbatim):");
		lines.push(loop.task);
		lines.push("");
		lines.push(
			"Make autonomous progress on the objective, but stay conservative: destructive/irreversible actions are gated this turn. If you need a human decision, stop and surface it rather than guessing.",
		);
		lines.push("");
	} else {
		lines.push("TASK (verbatim):");
		lines.push(loop.task);
		lines.push("");
	}
	lines.push(`This is iteration ${loop.iteration}/${loop.maxIterations}.`);
	if (loop.lastReason) {
		lines.push(`Previous decision: ${loop.lastReason}`);
	}
	if (loop.ultracode) {
		lines.push(
			`ULTRACODE: prefer driving this work via dynamic workflows when it earns its cost. Scout inline first with cheap read-only probes; orchestrate (dynamic_workflow action=start) only for exhaustiveness, independent confidence, or scale, with explicit concurrency/maxAgents. Inspect the catalog (dynamic_workflow action=scaffold) and reuse an exact-fit workflow or write a gitignored ${CONFIG_DIR_NAME}/workflows/drafts/<slug>.js draft.`,
		);
	}
	lines.push("");
	lines.push("Do EXACTLY ONE iteration of the task now, then decide whether to continue:");
	if (loop.mode === "fixed") {
		// Fixed mode: the period is owned by the extension; the model only decides
		// continue vs stop. loop_schedule is a no-op here (it cannot change cadence).
		const periodSec = Math.round((loop.intervalMs ?? 0) / 1000);
		lines.push(
			`- This loop runs on a FIXED interval (every ${formatInterval(periodSec)}). You do NOT control the cadence; do not try to change it.`,
		);
		lines.push(
			"- If more work remains, just finish this iteration; the next one will fire automatically on schedule.",
		);
		lines.push("- If the task is complete or no further iterations help, call loop_stop(reason) to end the loop.");
		lines.push(
			`The loop will keep firing on its fixed interval and will hard-stop at iteration ${loop.maxIterations} (or when its time budget is exhausted).`,
		);
	} else {
		lines.push(
			"- If more work / waiting is needed, call loop_schedule(delaySeconds, reason) to schedule the next iteration. Think about WHAT you are waiting for, not how long you want to sleep; pick a cadence accordingly.",
		);
		lines.push("- If the task is complete or no further iterations help, call loop_stop(reason) to end the loop.");
		lines.push(
			`If you do neither, the loop will auto-reschedule defensively and will hard-stop at iteration ${loop.maxIterations}.`,
		);
	}
	return lines.join("\n");
}