/**
 * Planner role prompts and degraded (no-LLM) plan generation.
 *
 * Production parent-session injects use slim messages only:
 * - `buildGoalSetContextMessage` while planning
 * - `buildExecuteKickoffPrompt` after plan is on disk
 * Do not reintroduce full draft-plan pastes into sendMessage content.
 */

import { expandToPlan } from "../plan/expand.ts";
import { renderPlan } from "../plan/template.ts";

/**
 * Prompt for an LLM planner subagent (optional path).
 * Criteria guidance draws on Critical Fallibilism / IGC: binary goals with
 * discrete breakpoints, not vague maximization.
 */
export function buildPlannerPrompt(objective: string): string {
  return [
    "You are the Goal Plan Writer for the pi-goal-expander harness.",
    "Research the codebase first (read/search), then write a structured plan.",
    "",
    "Write a Markdown plan with ALL of these sections, in order:",
    "1. `# Plan: <headline>`",
    "2. `## Goal kind` — exactly one of: `code-change` | `analysis` | `research`",
    "3. `## Acceptance criteria` — 3–5 gating criteria (see rules below)",
    "4. `## Verification plan` — steps tagged `gating` or `evidence`",
    "5. `## Non-goals`",
    "6. `## Assumed scope`",
    "7. `## Subgoals` — optional nested outcomes",
    "8. `## Implementation approach` — guidance only (not judged)",
    "9. `## Task checklist` — `- [ ]` items for the implementer",
    "10. `## Risks / Contradictions` — optional",
    "11. `## Deviations` — leave empty; append-only during execution",
    "",
    "## Criteria quality (Critical Fallibilism / IGC-style)",
    "Prefer **objectively measurable** outcomes with **discrete pass/fail breakpoints**:",
    "- Each criterion must have an unambiguous fact of the matter — pass or fail, not a vibe.",
    "- Convert maximization/soft goals into breakpoints of *enough* (with margin), e.g.",
    "  `npm run check` exits 0 — not \"tests feel good\"; latency ≤ N ms — not \"faster\".",
    "- Prefer discrete artifacts: exit codes, file contents, config keys, command output,",
    "  presence of paths, API responses — things a harness or human can re-check without debate.",
    "- Drop non-decisive factors that already have excess capacity; keep only goals that",
    "  can actually refute incomplete work.",
    "- Criteria are WHAT (outcomes), not HOW (file/function names) — unless the OBJECTIVE",
    "  names a specific artifact.",
    "",
    "Rules:",
    "- Keep it short, concrete, and unambiguous (aim 3–5 gating criteria).",
    "- Do NOT modify the workspace except writing the plan.",
    "- Do not invent unrequested scope; put extras under Non-goals.",
    "",
    `OBJECTIVE: ${objective}`,
    "",
    "Output ONLY the plan markdown (no preamble).",
  ].join("\n");
}

/** Immediate context inject when a goal is set and planner may still be running. */
export function buildGoalSetContextMessage(input: {
  objective: string;
  goalId: string;
  planPath: string;
  evidencePath: string;
  plannerPending: boolean;
}): string {
  const plannerLine = input.plannerPending
    ? [
        "**Planner status:** a planner subagent is running (or about to run) to research the",
        "codebase and write the plan file. Do **not** treat the goal as ready to execute yet",
        "and do **not** invent a parallel plan — wait for the execute kickoff after planning",
        "completes. You may continue other user work if asked, but the active goal is set.",
      ].join(" ")
    : "**Planner status:** planning finished (see execute kickoff if present).";

  return [
    "# Goal set",
    "",
    `**Goal id:** \`${input.goalId}\``,
    `**Objective:** ${input.objective}`,
    `**Plan path:** \`${input.planPath}\``,
    `**Evidence path:** \`${input.evidencePath}\``,
    "",
    plannerLine,
    "",
    "Goal state lives under `.pi/goal/` (cwd / `PI_GOAL_ROOT` / `PI_GOAL_CWD`);",
    "the objective may require edits **outside** that directory — edit scope follows the objective, not the goal store.",
    "",
    "When execute begins: read the plan **file on disk** (do not expect a pasted draft),",
    "fill the evidence index, and use `update_goal` for progress / completion / blocked.",
    "Required progress milestones: `researched`, `implementing`, `pre-complete` via `update_goal({ message })`.",
    "The harness verifies completion — you cannot self-certify.",
  ].join("\n");
}

/**
 * Degraded planner: structural expand + render without an LLM call.
 * Always produces a non-empty plan markdown string (draft skeleton).
 */
export function planFromExpansion(objective: string): string {
  const plan = expandToPlan(objective);
  return renderPlan(plan);
}