/**
 * TillDone — Condition-based task tracking for Speckl.
 * 
 * Tasks don't tick boxes. They evaluate predicates.
 * "Done" means a proven condition is met.
 */

import type { TillDoneCondition, TaskResult } from "./types.js";

export class TillDoneTracker {
  private conditions: Map<string, TillDoneCondition> = new Map();

  /** Register a completion condition for a task. */
  register(taskId: string, description: string, predicate: (result: TaskResult) => boolean): void {
    this.conditions.set(taskId, {
      taskId,
      description,
      predicate,
      isDone: false,
    });
  }

  /** Evaluate a task result against its condition. */
  evaluate(taskId: string, result: TaskResult): boolean {
    const condition = this.conditions.get(taskId);
    if (!condition) {
      throw new Error(`No TillDone condition registered for task ${taskId}`);
    }

    const satisfied = condition.predicate(result);
    condition.isDone = satisfied;
    return satisfied;
  }

  /** Check if a task's condition has been met. */
  isDone(taskId: string): boolean {
    return this.conditions.get(taskId)?.isDone ?? false;
  }

  /** Get all pending (not done) conditions. */
  pending(): TillDoneCondition[] {
    return [...this.conditions.values()].filter((c) => !c.isDone);
  }

  /** Get all completed conditions. */
  completed(): TillDoneCondition[] {
    return [...this.conditions.values()].filter((c) => c.isDone);
  }

  /** Built-in predicates for common Speckl conditions. */
  static predicates = {
    /** Z3 verification returned SAT (constraints satisfiable). */
    z3Verified: (result: TaskResult): boolean =>
      result.status === "success" &&
      (result.output as Record<string, unknown>)?.z3Result === "sat",

    /** All constraints are satisfiable (no contradictions). */
    noContradictions: (result: TaskResult): boolean =>
      result.status === "success" &&
      (result.output as Record<string, unknown>)?.contradictions === 0,

    /** Code generation produced valid output. */
    codeGenerated: (result: TaskResult): boolean =>
      result.status === "success" &&
      typeof (result.output as Record<string, unknown>)?.code === "string",

    /** Provenance graph is complete for this Speck. */
    provenanceComplete: (result: TaskResult): boolean =>
      result.status === "success" &&
      Array.isArray(result.provenance) &&
      result.provenance.length > 0,
  };
}