export const EXPERIENCE_RESULTS = Object.freeze(['success', 'partial', 'failure', 'unknown']);
export const EXPERIENCE_STATUSES = Object.freeze(['active', 'archived', 'deleted']);
export const EXPERIENCE_KINDS = Object.freeze([
  'lesson',
  'task_outcome',
  'execution_pattern',
  'skill_candidate',
]);

export const EXPERIENCE_V1_MYSQL_DDL = Object.freeze([
  'problem VARCHAR(512) NULL',
  'environment_json JSON NULL',
  'hypothesis VARCHAR(512) NULL',
  'action_json JSON NULL',
  "result ENUM('success','partial','failure','unknown') NULL",
  'confidence DECIMAL(4,3) NULL',
  'evidence_json JSON NULL',
  'parent_experience_id CHAR(36) NULL',
  'supersedes_id CHAR(36) NULL',
  "status ENUM('active','archived','deleted') NOT NULL DEFAULT 'active'",
]);

function nonEmptyString(value, maxLen = null) {
  const text = String(value ?? '').trim();
  if (!text) return null;
  return maxLen ? text.slice(0, maxLen) : text;
}

function normalizeConfidence(value) {
  if (value == null || value === '') return null;
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return null;
  return Math.min(1, Math.max(0, parsed));
}

function normalizeResult(value) {
  const text = String(value ?? '').trim().toLowerCase();
  if (!text) return null;
  return EXPERIENCE_RESULTS.includes(text) ? text : null;
}

function normalizeStatus(value) {
  const text = String(value ?? 'active').trim().toLowerCase();
  return EXPERIENCE_STATUSES.includes(text) ? text : 'active';
}

function normalizeKind(value) {
  const text = String(value ?? 'lesson').trim().toLowerCase();
  return EXPERIENCE_KINDS.includes(text) ? text : 'lesson';
}

export function serializeExperienceJson(value) {
  if (value == null) return null;
  if (typeof value === 'object') return JSON.stringify(value);
  const trimmed = String(value).trim();
  if (!trimmed) return null;
  JSON.parse(trimmed);
  return trimmed;
}

export function parseExperienceJson(value, fallback = null) {
  if (value == null) return fallback;
  if (typeof value === 'object') return value;
  try {
    return JSON.parse(String(value));
  } catch {
    return fallback;
  }
}

/**
 * Normalize caller input into stable DB-bound fields. Title/body remain required
 * at the service layer; structured fields are optional.
 */
export function normalizeExperienceRecordInput(input = {}) {
  return {
    scope: nonEmptyString(input.scope, 64) ?? 'global',
    kind: normalizeKind(input.kind),
    title: nonEmptyString(input.title, 255),
    body: nonEmptyString(input.body),
    tags: Array.isArray(input.tags)
      ? [...new Set(input.tags.map((tag) => String(tag).trim()).filter(Boolean))]
      : [],
    sourceSessionId: nonEmptyString(input.sourceSessionId, 128),
    sourceUserId: nonEmptyString(input.sourceUserId, 36),
    problem: nonEmptyString(input.problem, 512),
    environment: parseExperienceJson(input.environment ?? input.environmentJson, null),
    hypothesis: nonEmptyString(input.hypothesis, 512),
    action: parseExperienceJson(input.action ?? input.actionJson, null),
    result: normalizeResult(input.result),
    confidence: normalizeConfidence(input.confidence),
    evidence: parseExperienceJson(input.evidence ?? input.evidenceJson, null),
    parentExperienceId: nonEmptyString(input.parentExperienceId, 36),
    supersedesId: nonEmptyString(input.supersedesId, 36),
    status: normalizeStatus(input.status),
  };
}

export function mapExperienceRow(row) {
  return {
    id: row.id,
    scope: row.scope,
    kind: row.kind,
    title: row.title,
    body: row.body,
    tags: parseExperienceJson(row.tags_json ?? row.tags, []) ?? [],
    sourceSessionId: row.source_session_id ?? null,
    sourceUserId: row.source_user_id ?? null,
    useCount: Number(row.use_count ?? 0),
    createdAt: Number(row.created_at),
    updatedAt: Number(row.updated_at),
    problem: row.problem ?? null,
    environment: parseExperienceJson(row.environment_json, null),
    hypothesis: row.hypothesis ?? null,
    action: parseExperienceJson(row.action_json, null),
    result: row.result ?? null,
    confidence: row.confidence == null ? null : Number(row.confidence),
    evidence: parseExperienceJson(row.evidence_json, null),
    parentExperienceId: row.parent_experience_id ?? null,
    supersedesId: row.supersedes_id ?? null,
    status: row.status ?? 'active',
  };
}

export function experienceSearchHaystack(row) {
  const environmentText = row.environment_json
    ? JSON.stringify(parseExperienceJson(row.environment_json, {}))
    : '';
  return [
    row.title,
    row.body,
    row.problem,
    environmentText,
  ]
    .filter(Boolean)
    .join('\n')
    .toLowerCase();
}

export function formatExperienceInjectionBlock(hits = []) {
  if (!Array.isArray(hits) || hits.length === 0) return '';
  const lines = hits.map((hit) => formatExperienceInjectionLine(hit));
  return `# 相关经验（供参考，来自历史任务）\n${lines.join('\n')}`;
}

export function formatExperienceInjectionLine(hit) {
  const parts = [`- ${hit.title}: ${hit.body}`];
  if (hit.problem) parts.push(`  问题: ${hit.problem}`);
  if (hit.result) {
    const conf = hit.confidence == null ? '' : `, conf=${hit.confidence}`;
    parts.push(`  结果: ${hit.result}${conf}`);
  }
  const runtime = hit.environment?.runtime;
  const components = Array.isArray(hit.environment?.components)
    ? hit.environment.components.filter(Boolean).join(' + ')
    : '';
  if (runtime || components) {
    parts.push(`  环境: ${[runtime, components].filter(Boolean).join(' · ')}`);
  }
  return parts.join('\n');
}

/**
 * Build a structured task_outcome payload for MindSpace agent jobs.
 */
export function buildMindspaceJobExperiencePayload({ claim, sessionId, parsed, jobId = null } = {}) {
  const title = String(parsed?.title ?? claim?.instruction ?? '').trim().slice(0, 200);
  const summary = String(parsed?.summary ?? '').trim();
  if (!title || !summary) return null;

  const runRef = jobId ? String(jobId) : null;
  return normalizeExperienceRecordInput({
    kind: 'task_outcome',
    title,
    body: summary,
    problem: claim?.instruction ?? title,
    result: parsed?.status === 'failed' ? 'failure' : 'success',
    sourceSessionId: sessionId ?? null,
    sourceUserId: claim?.userId ?? null,
    environment: {
      runtime: 'mindspace-agent-job',
      components: ['goose', 'portal'],
    },
    action: {
      executor: 'goose',
      steps: ['agent_job_complete'],
      artifacts: Array.isArray(parsed?.sourceAssetIds) ? parsed.sourceAssetIds : [],
    },
    evidence: {
      sources: runRef
        ? [{
          source_id: `job:${runRef}`,
          source_type: 'agent_job',
          actor: 'goose',
          timestamp_ms: Date.now(),
          modality: 'task_result',
        }]
        : [],
      provenance: {
        session_id: sessionId ?? null,
        user_id: claim?.userId ?? null,
        job_id: runRef,
      },
    },
  });
}