import { and, desc, eq, inArray, sql } from "drizzle-orm";
import { agents, agentWakeupRequests, approvals, companies, heartbeatRuns, issueApprovals, issueRecoveryActions,
  issues, issueTreeHoldMembers, issueTreeHolds, projects, type Db } from "@paperclipai/db";
import type { TaskInterruptionPresentation } from "@paperclipai/shared";
import { isAiAuthenticationBlocked } from "./ai-auth-failure.js";
import { readSystemRecovery } from "./system-recovery-state.js";

type ProjectionIssue = Pick<typeof issues.$inferSelect, "id" | "companyId" | "status" | "assigneeAgentId" | "projectId">;
type ProjectionRun = Pick<typeof heartbeatRuns.$inferSelect,
  "id" | "status" | "scheduledRetryAt" | "errorCode" | "livenessState" | "resultJson">;
type ProjectionState = {
  run?: ProjectionRun;
  action?: typeof issueRecoveryActions.$inferSelect;
  wait?: { id: string; requestedAt: Date };
  agent?: Pick<typeof agents.$inferSelect, "status" | "pauseReason">;
  project?: Pick<typeof projects.$inferSelect, "pausedAt" | "pauseReason">;
  company?: Pick<typeof companies.$inferSelect, "status" | "pauseReason">;
  paused: boolean;
  approval: boolean;
};

/** Presentation never grants authority. Dispatch repeats all gates under its
 * locks. The same projection is used in detail, lists and attention surfaces. */
export function projectTaskInterruption(issue: ProjectionIssue, input: ProjectionState, now = Date.now()): TaskInterruptionPresentation | null {
  const { run, wait, action, agent, project, company } = input;
  if (!run) return null;
  const system = readSystemRecovery(action?.evidence);
  const base: TaskInterruptionPresentation = { intentId: wait?.id ?? null, responsibility: "system",
    state: "resolved", nextRetryAt: null, canRetry: false, userAction: null,
    sourceRunIds: [run.id], observedRunId: run.id };
  if (["done", "cancelled"].includes(issue.status) || (run.status === "succeeded" && !wait)) return base;
  const userAction = !issue.assigneeAgentId ? "assign_agent" : input.approval || run.errorCode === "native_provider_approval_required" ? "approval"
    : isAiAuthenticationBlocked(run) ? "reconnect"
      : run.errorCode === "native_provider_model_rejected" ? "choose_model"
      : [agent?.pauseReason, project?.pauseReason, company?.pauseReason].some(reason => reason === "budget" || reason === "budget_exceeded")
        ? "budget" : input.paused || project?.pausedAt || agent?.status === "paused" || company?.status === "paused" ? "resume" : null;
  if (userAction) return { ...base, responsibility: "user", state: "waiting_for_user", userAction };
  if (["running", "queued"].includes(run.status)) return { ...base, state: "working" };
  const retryAt = system?.nextAttemptAt ?? run.scheduledRetryAt?.getTime();
  if (retryAt && retryAt > now) return { ...base, state: "retry_scheduled",
    nextRetryAt: new Date(retryAt).toISOString(), canRetry: true };
  const activeObservation = action?.evidence.systemRecoveryActiveAt;
  if (system?.state === "running" && typeof activeObservation === "number" &&
      activeObservation > now - 45_000) return { ...base, state: "working" };
  if (wait && wait.requestedAt.getTime() > now - 10_000 && system?.state !== "exhausted")
    return { ...base, state: "working" };
  return { ...base, state: "failed", canRetry: true };
}

/** Batch list reads rather than doing seven queries per row. Keep run logs and
 * large result bodies out of this projection; only authentication evidence is
 * needed for the typed reconnect action. */
export async function taskInterruptionPresentations(db: Db, companyId: string, input: ProjectionIssue[]) {
  const selected = input.filter(issue => issue.companyId === companyId);
  const result = new Map<string, TaskInterruptionPresentation | null>();
  if (!selected.length) return result;
  const ids = selected.map(issue => issue.id);
  const runIssue = sql<string>`coalesce(${heartbeatRuns.nativeIssueId}::text, ${heartbeatRuns.issueId}::text, ${heartbeatRuns.contextSnapshot}->>'issueId')`;
  const wakeIssue = sql<string>`${agentWakeupRequests.payload}->>'issueId'`;
  const agentIds = selected.flatMap(issue => issue.assigneeAgentId ? [issue.assigneeAgentId] : []);
  const projectIds = selected.flatMap(issue => issue.projectId ? [issue.projectId] : []);
  const [runs, waits, agentRows, projectRows, pauseRows, approvalRows, companyRows] = await Promise.all([
    db.selectDistinctOn([runIssue], { issueId: runIssue, id: heartbeatRuns.id, status: heartbeatRuns.status,
      errorCode: heartbeatRuns.errorCode, livenessState: heartbeatRuns.livenessState, scheduledRetryAt: heartbeatRuns.scheduledRetryAt,
      resultJson: sql<Record<string, unknown>>`jsonb_build_object('configurationIncomplete', ${heartbeatRuns.resultJson}->'configurationIncomplete')`,
    }).from(heartbeatRuns).where(and(eq(heartbeatRuns.companyId, companyId), inArray(runIssue, ids)))
      .orderBy(runIssue, desc(heartbeatRuns.createdAt), desc(heartbeatRuns.id)),
    db.selectDistinctOn([wakeIssue], { issueId: wakeIssue, id: agentWakeupRequests.id, requestedAt: agentWakeupRequests.requestedAt })
      .from(agentWakeupRequests).where(and(eq(agentWakeupRequests.companyId, companyId), inArray(wakeIssue, ids),
        eq(agentWakeupRequests.status, "deferred_issue_execution"), eq(agentWakeupRequests.requestedByActorType, "user")))
      .orderBy(wakeIssue, desc(agentWakeupRequests.requestedAt)),
    agentIds.length ? db.select({ id: agents.id, status: agents.status, pauseReason: agents.pauseReason }).from(agents)
      .where(and(eq(agents.companyId, companyId), inArray(agents.id, agentIds))) : [],
    projectIds.length ? db.select({ id: projects.id, pausedAt: projects.pausedAt, pauseReason: projects.pauseReason }).from(projects)
      .where(and(eq(projects.companyId, companyId), inArray(projects.id, projectIds))) : [],
    db.select({ issueId: issueTreeHoldMembers.issueId }).from(issueTreeHoldMembers).innerJoin(issueTreeHolds, and(
      eq(issueTreeHolds.companyId, issueTreeHoldMembers.companyId), eq(issueTreeHolds.id, issueTreeHoldMembers.holdId)))
      .where(and(eq(issueTreeHoldMembers.companyId, companyId), inArray(issueTreeHoldMembers.issueId, ids),
        eq(issueTreeHolds.status, "active"), eq(issueTreeHolds.mode, "pause"))),
    db.select({ issueId: issueApprovals.issueId }).from(issueApprovals).innerJoin(approvals, and(
      eq(approvals.companyId, issueApprovals.companyId), eq(approvals.id, issueApprovals.approvalId)))
      .where(and(eq(issueApprovals.companyId, companyId), inArray(issueApprovals.issueId, ids),
        inArray(approvals.status, ["pending", "revision_requested"]))),
    db.select({ status: companies.status, pauseReason: companies.pauseReason }).from(companies).where(eq(companies.id, companyId)),
  ]);
  const runIds = runs.map(run => run.id);
  const actions = runIds.length ? await db.selectDistinctOn([issueRecoveryActions.sourceIssueId]).from(issueRecoveryActions).where(and(
    eq(issueRecoveryActions.companyId, companyId), inArray(issueRecoveryActions.sourceIssueId, ids),
    inArray(sql`${issueRecoveryActions.evidence}->>'runId'`, runIds),
    sql`${issueRecoveryActions.evidence} ? 'systemRecovery'`,
  )).orderBy(issueRecoveryActions.sourceIssueId, desc(issueRecoveryActions.createdAt)) : [];
  const byIssue = <T extends { issueId: string }>(rows: T[]) => new Map(rows.map(row => [row.issueId, row]));
  const runMap = byIssue(runs), waitMap = byIssue(waits);
  const actionMap = new Map(actions.map(action => [action.sourceIssueId, action]));
  const agentMap = new Map(agentRows.map(agent => [agent.id, agent]));
  const projectMap = new Map(projectRows.map(project => [project.id, project]));
  const pauses = new Set(pauseRows.map(row => row.issueId)), approvalsSet = new Set(approvalRows.map(row => row.issueId));
  for (const issue of selected) result.set(issue.id, projectTaskInterruption(issue, {
    run: runMap.get(issue.id), action: actionMap.get(issue.id), wait: waitMap.get(issue.id),
    agent: agentMap.get(issue.assigneeAgentId ?? ""), project: projectMap.get(issue.projectId ?? ""),
    company: companyRows[0], paused: pauses.has(issue.id), approval: approvalsSet.has(issue.id),
  }));
  return result;
}

export async function taskInterruptionPresentation(db: Db, issue: ProjectionIssue) {
  return (await taskInterruptionPresentations(db, issue.companyId, [issue])).get(issue.id) ?? null;
}