import { Type } from "@sinclair/typebox";
import type { ExtensionAPI } from "../_shared/pi-api.js";
import { errorResult, getCommandText, setTextWidget } from "../_shared/pi-api.js";
import { validateParams } from "../_shared/validation.js";

const GoalSetParams = Type.Object({
  objective: Type.String({ description: "Goal text", minLength: 1, maxLength: 2000 }),
  constraints: Type.Optional(Type.Array(Type.String({ maxLength: 500 }), { maxItems: 20 })),
  doneCriteria: Type.Optional(Type.Array(Type.String({ maxLength: 200 }), { maxItems: 10 })),
});

const GoalParams = Type.Object({
  op: Type.Union([
    Type.Literal("create"),
    Type.Literal("get"),
    Type.Literal("complete"),
    Type.Literal("resume"),
    Type.Literal("drop"),
  ], { description: "OMP goal operation" }),
  objective: Type.Optional(Type.String({ description: "Goal objective for op=create", minLength: 1, maxLength: 8000 })),
  token_budget: Type.Optional(Type.Integer({ description: "Positive token budget for op=create", minimum: 1 })),
});

export default function goal(pi: ExtensionAPI): void {
  pi.registerTool({
    name: "goal",
    description: "OMP-shaped goal contract. Fails closed until OMP GoalRuntime is ported.",
    parameters: GoalParams,
    async execute(_toolCallId, params) {
      const valid = validateParams(GoalParams, params);
      if (!valid.ok) return valid.result;
      return goalNotPorted(valid.value.op);
    },
  });

  pi.registerTool({
    name: "goalSet",
    description: "Legacy alias for the old local goal state. Fails closed until OMP GoalRuntime is ported.",
    parameters: GoalSetParams,
    async execute(_toolCallId, params) {
      const valid = validateParams(GoalSetParams, params);
      if (!valid.ok) return valid.result;
      return goalNotPorted("create", "goalSet");
    },
  });

  pi.registerCommand("goal", {
    description: "Show fail-closed OMP goal status until GoalRuntime is ported.",
    handler: async (args, ctx) => {
      const [action = "show"] = getCommandText(args).trim().split(/\s+/);
      const op = commandActionToGoalOp(action);
      const result = goalNotPorted(op, "goal-command");
      ctx.ui.setStatus("goal", "disabled until OMP GoalRuntime port");
      setTextWidget(ctx, "goal", result.content[0]?.type === "text" ? result.content[0].text : "goal runtime is not available");
    },
  });
}

function commandActionToGoalOp(action: string): "create" | "get" | "complete" | "resume" | "drop" {
  if (action === "set" || action === "create") return "create";
  if (action === "done" || action === "complete") return "complete";
  if (action === "resume") return "resume";
  if (action === "clear" || action === "drop") return "drop";
  return "get";
}

function goalNotPorted(op: "create" | "get" | "complete" | "resume" | "drop", requestedSurface: "goal" | "goalSet" | "goal-command" = "goal") {
  return errorResult(
    [
      "Goal runtime is disabled in miloc-pi.",
      "OMP `goal` is the source truth for create/get/resume/drop/complete, token budgets, status transitions, continuation prompts, and completion audit.",
      "This extension does not inject hidden goal context until OMP GoalRuntime is ported here.",
    ].join("\n"),
    {
      owner: "omp-goal",
      ported: false,
      requestedSurface,
      op,
      ompSources: [
        "packages/coding-agent/src/goals/tools/goal-tool.ts",
        "packages/coding-agent/src/goals/runtime.ts",
        "packages/coding-agent/src/goals/state.ts",
        "packages/coding-agent/src/prompts/tools/goal.md",
        "packages/coding-agent/src/prompts/goals/goal-mode-active.md",
        "packages/coding-agent/src/prompts/goals/goal-continuation.md",
        "packages/coding-agent/src/session/agent-session.ts",
      ],
    },
  );
}