import type { PublicUsage, SubagentDetailsV1 } from './coding-conversation-contracts';

const STATUSES = new Set(['queued', 'running', 'complete', 'error', 'aborted', 'skipped']);

function recordValue(value: unknown): Record<string, unknown> | null {
  return value !== null && typeof value === 'object' && !Array.isArray(value)
    ? value as Record<string, unknown>
    : null;
}

function publicUsage(value: unknown): PublicUsage | undefined {
  const usage = recordValue(value);
  if (!usage
    || typeof usage.inputTokens !== 'number'
    || typeof usage.outputTokens !== 'number'
    || !Number.isFinite(usage.inputTokens)
    || !Number.isFinite(usage.outputTokens)
    || usage.inputTokens < 0
    || usage.outputTokens < 0
    || (usage.cacheReadTokens !== undefined
      && (typeof usage.cacheReadTokens !== 'number'
        || !Number.isFinite(usage.cacheReadTokens)
        || usage.cacheReadTokens < 0))
    || (usage.cacheWriteTokens !== undefined
      && (typeof usage.cacheWriteTokens !== 'number'
        || !Number.isFinite(usage.cacheWriteTokens)
        || usage.cacheWriteTokens < 0))) {
    return undefined;
  }
  return {
    inputTokens: usage.inputTokens,
    outputTokens: usage.outputTokens,
    ...(typeof usage.cacheReadTokens === 'number' ? { cacheReadTokens: usage.cacheReadTokens } : {}),
    ...(typeof usage.cacheWriteTokens === 'number' ? { cacheWriteTokens: usage.cacheWriteTokens } : {}),
  };
}

export function projectSubagentDetailsV1(value: unknown): SubagentDetailsV1 | undefined {
  const record = recordValue(value);
  if (!record
    || record.schema !== 'subagent.v1'
    || typeof record.dispatchId !== 'string'
    || !record.dispatchId.trim()
    || !['single', 'parallel', 'chain'].includes(String(record.mode))
    || !Array.isArray(record.tasks)
    || record.tasks.length === 0
    || record.tasks.length > 8) return undefined;
  const tasks: SubagentDetailsV1['tasks'] = [];
  for (const value of record.tasks) {
    const task = recordValue(value);
    if (!task
      || typeof task.taskId !== 'string'
      || !task.taskId.trim()
      || typeof task.agentId !== 'string'
      || !task.agentId.trim()
      || (task.toolProfile !== 'read-only' && task.toolProfile !== 'coding')
      || !STATUSES.has(String(task.status))
      || (task.summary !== undefined && typeof task.summary !== 'string')
      || (task.errorCode !== undefined && typeof task.errorCode !== 'string')) return undefined;
    const usage = task.usage === undefined ? undefined : publicUsage(task.usage);
    if (task.usage !== undefined && !usage) return undefined;
    tasks.push({
      taskId: task.taskId,
      agentId: task.agentId,
      toolProfile: task.toolProfile,
      status: task.status as SubagentDetailsV1['tasks'][number]['status'],
      ...(typeof task.summary === 'string' ? { summary: task.summary.slice(0, 4_000) } : {}),
      ...(typeof task.errorCode === 'string' ? { errorCode: task.errorCode.slice(0, 64) } : {}),
      ...(usage ? { usage } : {}),
    });
  }
  return {
    schema: 'subagent.v1',
    dispatchId: record.dispatchId,
    mode: record.mode as SubagentDetailsV1['mode'],
    tasks,
  };
}

export function subagentDetailsOfResult(value: unknown): SubagentDetailsV1 | undefined {
  return projectSubagentDetailsV1(recordValue(value)?.details);
}