// Release — Constraint block.
//
// The task may not start before `earliestStart` (a day index in the
// resolved calendar frame) — material arrival, permit dates, or frozen
// in-progress work compiled down from a re-leveling run.
//
// MiniZinc compile contract: harness supplies `start_day[t]`.

import { z } from "zod";

import type { ReleaseConstraint } from "../level-core/types.ts";

import type { ConstraintBlock, MiniZincFragment } from "./types.ts";

export const ReleaseInputSchema = z.object({
  taskUniqueId: z.number().int(),
  earliestStart: z.number().int().nonnegative(),
});

export type ReleaseInput = z.infer<typeof ReleaseInputSchema>;

const ReleaseOutputSchema: z.ZodType<ReleaseConstraint> = z.object({
  kind: z.literal("Release"),
  taskUniqueId: z.number().int(),
  earliestStart: z.number().int().nonnegative(),
});

export const ReleaseBlock: ConstraintBlock<ReleaseInput> = {
  id: "Release",
  schema: { input: ReleaseInputSchema, output: ReleaseOutputSchema },
  apply: ({ taskUniqueId, earliestStart }): ReleaseConstraint => ({
    kind: "Release",
    taskUniqueId,
    earliestStart,
  }),
  toMiniZinc: ({ taskUniqueId, earliestStart }): MiniZincFragment => ({
    text: `constraint start_day[${String(taskUniqueId)}] >= ${String(earliestStart)};`,
  }),
  doc: {
    nl: "The task may not start before the given day index.",
    pseudocode: "start(task) >= earliestStart",
  },
};