/**
 * Time Tracking — Timesheets server actions.
 *
 * Cycle 12 (Phase 2): per-worker pay-period timesheets with a Draft →
 * Submitted → Approved/Locked workflow. Only `platform_admin` /
 * `brand_admin` can unlock a locked timesheet, and that requires a
 * mandatory audit note.
 *
 * Authorisation model:
 *   - platform_admin / brand_admin — full access across their brand
 *   - supervisor (field_workers.role = 'supervisor') — read + approve
 *     timesheets for assigned supervisees only
 *   - worker (field_workers.role IN ('worker','driver')) — can only
 *     read their own timesheets and submit (draft → submitted); cannot
 *     approve / unlock
 *
 * Concurrency:
 *   - All mutations run inside a single `withTx` block so the timesheet
 *     status + the audit row + the recompute RPC commit atomically.
 */
"use server";

import {
  and,
  desc,
  eq,
  gte,
  inArray,
  lte,
  sql,
  type SQL,
} from "drizzle-orm";
import { z } from "zod";
import { getAdminUser } from "@/lib/admin-permissions";
import { getPool, withTx } from "@/lib/db";
import { withBrand, withPlatformAdmin } from "@/db/client";
import {
  timeTrackingLogs,
  timeTrackingTimesheets,
  timeTrackingSupervisorAssignments,
  timeTrackingAuditLog,
  type TimesheetStatus,
} from "@/db/schema/time-tracking";
import { fieldWorkers } from "@/db/schema/field-workers";
import {
  logTimeTrackingEventInTx,
} from "@/lib/time-tracking-audit";
import { payPeriodForDate, toIsoDate } from "@/lib/time-tracking/period";

// ── Period math ────────────────────────────────────────────────────────────
// `payPeriodForDate` / `toIsoDate` live in `@/lib/time-tracking/period`
// so client components can use them too — server-action files
// ("use server") can only export async functions.

// ── Types ──────────────────────────────────────────────────────────────────

export type TimesheetEntry = {
  id: string;
  brand_id: string;
  field_worker_id: string;
  worker_name: string;
  task_id: string | null;
  task_name: string;
  clock_in: string;
  clock_out: string | null;
  lunch_break_minutes: number;
  notes: string | null;
  submitted_via: string;
  entry_kind: "clock" | "manual";
  manual_reason: string | null;
  gps_verified: boolean;
  clock_in_lat: number | null;
  clock_in_lng: number | null;
  clock_in_accuracy_m: number | null;
  clock_out_lat: number | null;
  clock_out_lng: number | null;
  clock_out_accuracy_m: number | null;
  edited_at: string | null;
  edited_by_label: string | null;
  edit_reason: string | null;
  total_minutes: number;
};

export type TimesheetSummary = {
  id: string;
  brand_id: string;
  field_worker_id: string;
  worker_name: string;
  worker_role: string;
  period_start: string;
  period_end: string;
  status: TimesheetStatus;
  total_minutes: number;
  regular_minutes: number;
  overtime_minutes: number;
  break_minutes: number;
  entry_count: number;
  daily_totals: Record<string, number>;
  submitted_at: string | null;
  submitted_notes: string | null;
  reviewed_at: string | null;
  reviewed_by_label: string | null;
  reviewer_comment: string | null;
  rejected_at: string | null;
  rejection_reason: string | null;
  locked_at: string | null;
  unlocked_at: string | null;
  unlock_audit_note: string | null;
  updated_at: string;
};

export type AuditEntry = {
  id: string;
  actor_id: string | null;
  actor_label: string;
  actor_kind: string;
  action: string;
  entity_type: string;
  entity_id: string | null;
  details: Record<string, unknown>;
  created_at: string;
};

// ── Auth helpers ───────────────────────────────────────────────────────────

type CallerKind = "platform_admin" | "brand_admin" | "supervisor" | "worker";

type CallerContext = {
  adminUser: NonNullable<Awaited<ReturnType<typeof getAdminUser>>>;
  kind: CallerKind;
  brandId: string;
  /** When kind === 'supervisor', the field_worker row id of the supervisor. */
  supervisorFieldWorkerId: string | null;
};

/**
 * Resolve the caller's role + brand context. Admins (platform/brand) are
 * detected by `admin_users.role`. Supervisors are detected by matching
 * `field_workers.role = 'supervisor'` for the admin's email.
 */
async function resolveCaller(brandId?: string): Promise<CallerContext | null> {
  const adminUser = await getAdminUser();
  if (!adminUser) return null;

  const resolvedBrandId = brandId ?? adminUser.brand_id ?? null;
  if (!resolvedBrandId) return null;

  if (adminUser.role === "platform_admin") {
    return {
      adminUser,
      kind: "platform_admin",
      brandId: resolvedBrandId,
      supervisorFieldWorkerId: null,
    };
  }

  if (adminUser.role === "brand_admin") {
    return {
      adminUser,
      kind: "brand_admin",
      brandId: resolvedBrandId,
      supervisorFieldWorkerId: null,
    };
  }

  // store_employee or other: lookup as supervisor via email match
  return withPlatformAdmin(async (db) => {
    const fw = await db
      .select()
      .from(fieldWorkers)
      .where(
        and(
          eq(fieldWorkers.brandId, adminUser.brand_id ?? ""),
          sql`LOWER(${fieldWorkers.name}) = LOWER(${adminUser.email ?? ""})`,
          eq(fieldWorkers.role, "supervisor"),
        ),
      )
      .limit(1);
    if (fw.length > 0) {
      return {
        adminUser,
        kind: "supervisor" as const,
        brandId: resolvedBrandId,
        supervisorFieldWorkerId: fw[0].id,
      };
    }
    return {
      adminUser,
      kind: "worker" as const,
      brandId: resolvedBrandId,
      supervisorFieldWorkerId: null,
    };
  });
}

// ── List timesheets ────────────────────────────────────────────────────────

export async function listTimesheets(
  brandId: string,
  options: {
    status?: TimesheetStatus | "all";
    workerId?: string;
    periodStart?: string; // YYYY-MM-DD
    periodEnd?: string;
    limit?: number;
    offset?: number;
  } = {},
): Promise<{ rows: TimesheetSummary[]; total: number }> {
  const caller = await resolveCaller(brandId);
  if (!caller) return { rows: [], total: 0 };

  return withBrand(caller.brandId, async (db) => {
    const conds: SQL[] = [eq(timeTrackingTimesheets.brandId, caller.brandId)];
    if (options.status && options.status !== "all") {
      conds.push(
        eq(timeTrackingTimesheets.status, options.status as TimesheetStatus),
      );
    }
    if (options.workerId) {
      conds.push(eq(timeTrackingTimesheets.fieldWorkerId, options.workerId));
    }
    if (options.periodStart) {
      conds.push(gte(timeTrackingTimesheets.periodStart, options.periodStart));
    }
    if (options.periodEnd) {
      conds.push(lte(timeTrackingTimesheets.periodEnd, options.periodEnd));
    }

    // Supervisor scoping: only their assigned supervisees
    if (caller.kind === "supervisor" && caller.supervisorFieldWorkerId) {
      const assigned = await db
        .select({
          id: timeTrackingSupervisorAssignments.superviseeFieldWorkerId,
        })
        .from(timeTrackingSupervisorAssignments)
        .where(
          eq(
            timeTrackingSupervisorAssignments.supervisorFieldWorkerId,
            caller.supervisorFieldWorkerId,
          ),
        );
      const ids = assigned.map((a) => a.id);
      if (ids.length === 0) return { rows: [], total: 0 };
      conds.push(inArray(timeTrackingTimesheets.fieldWorkerId, ids));
    }

    const limit = Math.min(options.limit ?? 100, 500);
    const offset = Math.max(options.offset ?? 0, 0);

    const rows = await db
      .select({
        id: timeTrackingTimesheets.id,
        brand_id: timeTrackingTimesheets.brandId,
        field_worker_id: timeTrackingTimesheets.fieldWorkerId,
        worker_name: fieldWorkers.name,
        worker_role: fieldWorkers.role,
        period_start: timeTrackingTimesheets.periodStart,
        period_end: timeTrackingTimesheets.periodEnd,
        status: timeTrackingTimesheets.status,
        total_minutes: timeTrackingTimesheets.totalMinutes,
        regular_minutes: timeTrackingTimesheets.regularMinutes,
        overtime_minutes: timeTrackingTimesheets.overtimeMinutes,
        break_minutes: timeTrackingTimesheets.breakMinutes,
        entry_count: timeTrackingTimesheets.entryCount,
        daily_totals: timeTrackingTimesheets.dailyTotals,
        submitted_at: timeTrackingTimesheets.submittedAt,
        submitted_notes: timeTrackingTimesheets.submittedNotes,
        reviewed_at: timeTrackingTimesheets.reviewedAt,
        reviewer_comment: timeTrackingTimesheets.reviewerComment,
        rejected_at: timeTrackingTimesheets.rejectedAt,
        rejection_reason: timeTrackingTimesheets.rejectionReason,
        locked_at: timeTrackingTimesheets.lockedAt,
        unlocked_at: timeTrackingTimesheets.unlockedAt,
        unlock_audit_note: timeTrackingTimesheets.unlockAuditNote,
        updated_at: timeTrackingTimesheets.updatedAt,
      })
      .from(timeTrackingTimesheets)
      .leftJoin(
        fieldWorkers,
        eq(fieldWorkers.id, timeTrackingTimesheets.fieldWorkerId),
      )
      .where(and(...conds))
      .orderBy(desc(timeTrackingTimesheets.periodStart))
      .limit(limit)
      .offset(offset);

    const totalRes = await db
      .select({ count: sql<number>`COUNT(*)::int` })
      .from(timeTrackingTimesheets)
      .where(and(...conds));

    return {
      rows: rows.map((r) =>
        rowToSummary({
          ...r,
          daily_totals: (r.daily_totals ?? {}) as Record<string, number>,
          reviewed_by_label: null,
        }),
      ),
      total: totalRes[0]?.count ?? 0,
    };
  });
}

function rowToSummary(r: {
  id: string;
  brand_id: string;
  field_worker_id: string;
  worker_name: string | null;
  worker_role: string | null;
  period_start: string;
  period_end: string;
  status: TimesheetStatus;
  total_minutes: number;
  regular_minutes: number;
  overtime_minutes: number;
  break_minutes: number;
  entry_count: number;
  daily_totals: Record<string, number> | null;
  submitted_at: Date | null;
  submitted_notes: string | null;
  reviewed_at: Date | null;
  reviewer_comment: string | null;
  rejected_at: Date | null;
  rejection_reason: string | null;
  locked_at: Date | null;
  unlocked_at: Date | null;
  unlock_audit_note: string | null;
  updated_at: Date;
  reviewed_by_label: string | null;
}): TimesheetSummary {
  return {
    id: r.id,
    brand_id: r.brand_id,
    field_worker_id: r.field_worker_id,
    worker_name: r.worker_name ?? "(unknown)",
    worker_role: r.worker_role ?? "worker",
    period_start: r.period_start,
    period_end: r.period_end,
    status: r.status,
    total_minutes: r.total_minutes,
    regular_minutes: r.regular_minutes,
    overtime_minutes: r.overtime_minutes,
    break_minutes: r.break_minutes,
    entry_count: r.entry_count,
    daily_totals: r.daily_totals ?? {},
    submitted_at: r.submitted_at ? r.submitted_at.toISOString() : null,
    submitted_notes: r.submitted_notes,
    reviewed_at: r.reviewed_at ? r.reviewed_at.toISOString() : null,
    reviewed_by_label: r.reviewed_by_label,
    reviewer_comment: r.reviewer_comment,
    rejected_at: r.rejected_at ? r.rejected_at.toISOString() : null,
    rejection_reason: r.rejection_reason,
    locked_at: r.locked_at ? r.locked_at.toISOString() : null,
    unlocked_at: r.unlocked_at ? r.unlocked_at.toISOString() : null,
    unlock_audit_note: r.unlock_audit_note,
    updated_at: r.updated_at.toISOString(),
  };
}

// ── Get a single timesheet (with entries + audit) ─────────────────────────

export async function getTimesheet(
  timesheetId: string,
): Promise<{
  summary: TimesheetSummary;
  entries: TimesheetEntry[];
  audit: AuditEntry[];
} | null> {
  const caller = await resolveCaller();
  if (!caller) return null;

  return withBrand(caller.brandId, async (db) => {
    const [row] = await db
      .select({
        id: timeTrackingTimesheets.id,
        brand_id: timeTrackingTimesheets.brandId,
        field_worker_id: timeTrackingTimesheets.fieldWorkerId,
        worker_name: fieldWorkers.name,
        worker_role: fieldWorkers.role,
        period_start: timeTrackingTimesheets.periodStart,
        period_end: timeTrackingTimesheets.periodEnd,
        status: timeTrackingTimesheets.status,
        total_minutes: timeTrackingTimesheets.totalMinutes,
        regular_minutes: timeTrackingTimesheets.regularMinutes,
        overtime_minutes: timeTrackingTimesheets.overtimeMinutes,
        break_minutes: timeTrackingTimesheets.breakMinutes,
        entry_count: timeTrackingTimesheets.entryCount,
        daily_totals: timeTrackingTimesheets.dailyTotals,
        submitted_at: timeTrackingTimesheets.submittedAt,
        submitted_notes: timeTrackingTimesheets.submittedNotes,
        reviewed_at: timeTrackingTimesheets.reviewedAt,
        reviewer_comment: timeTrackingTimesheets.reviewerComment,
        rejected_at: timeTrackingTimesheets.rejectedAt,
        rejection_reason: timeTrackingTimesheets.rejectionReason,
        locked_at: timeTrackingTimesheets.lockedAt,
        unlocked_at: timeTrackingTimesheets.unlockedAt,
        unlock_audit_note: timeTrackingTimesheets.unlockAuditNote,
        updated_at: timeTrackingTimesheets.updatedAt,
      })
      .from(timeTrackingTimesheets)
      .leftJoin(
        fieldWorkers,
        eq(fieldWorkers.id, timeTrackingTimesheets.fieldWorkerId),
      )
      .where(
        and(
          eq(timeTrackingTimesheets.id, timesheetId),
          eq(timeTrackingTimesheets.brandId, caller.brandId),
        ),
      )
      .limit(1);
    if (!row) return null;

    // Auth scope check for supervisors
    if (caller.kind === "supervisor" && caller.supervisorFieldWorkerId) {
      const assigned = await db
        .select({
          id: timeTrackingSupervisorAssignments.superviseeFieldWorkerId,
        })
        .from(timeTrackingSupervisorAssignments)
        .where(
          and(
            eq(
              timeTrackingSupervisorAssignments.supervisorFieldWorkerId,
              caller.supervisorFieldWorkerId,
            ),
            eq(
              timeTrackingSupervisorAssignments.superviseeFieldWorkerId,
              row.field_worker_id,
            ),
          ),
        )
        .limit(1);
      if (assigned.length === 0) return null;
    }

    // Entries
    const entryRows = await db
      .select({
        id: timeTrackingLogs.id,
        brand_id: timeTrackingLogs.brandId,
        field_worker_id: timeTrackingLogs.fieldWorkerId,
        worker_name: fieldWorkers.name,
        task_id: timeTrackingLogs.taskId,
        task_name: timeTrackingLogs.taskName,
        clock_in: timeTrackingLogs.clockIn,
        clock_out: timeTrackingLogs.clockOut,
        lunch_break_minutes: timeTrackingLogs.lunchBreakMinutes,
        notes: timeTrackingLogs.notes,
        submitted_via: timeTrackingLogs.submittedVia,
        entry_kind: timeTrackingLogs.entryKind,
        manual_reason: timeTrackingLogs.manualReason,
        gps_verified: timeTrackingLogs.gpsVerified,
        clock_in_lat: timeTrackingLogs.clockInLat,
        clock_in_lng: timeTrackingLogs.clockInLng,
        clock_in_accuracy_m: timeTrackingLogs.clockInAccuracyM,
        clock_out_lat: timeTrackingLogs.clockOutLat,
        clock_out_lng: timeTrackingLogs.clockOutLng,
        clock_out_accuracy_m: timeTrackingLogs.clockOutAccuracyM,
        edited_at: timeTrackingLogs.editedAt,
        edit_reason: timeTrackingLogs.editReason,
      })
      .from(timeTrackingLogs)
      .leftJoin(
        fieldWorkers,
        eq(fieldWorkers.id, timeTrackingLogs.fieldWorkerId),
      )
      .where(
        and(
          eq(timeTrackingLogs.brandId, caller.brandId),
          eq(timeTrackingLogs.fieldWorkerId, row.field_worker_id),
          gte(timeTrackingLogs.clockIn, new Date(row.period_start)),
          lte(timeTrackingLogs.clockIn, endOfDay(row.period_end)),
        ),
      )
      .orderBy(timeTrackingLogs.clockIn);

    const entryIds = entryRows.map((e) => e.id);
    const auditRows = entryIds.length
      ? await db
          .select()
          .from(timeTrackingAuditLog)
          .where(
            and(
              eq(timeTrackingAuditLog.brandId, caller.brandId),
              sql`(${timeTrackingAuditLog.entityType} = 'timesheet' AND ${timeTrackingAuditLog.entityId} = ${timesheetId}) OR (${timeTrackingAuditLog.entityType} = 'log' AND ${timeTrackingAuditLog.entityId} IN (${sql.join(entryIds.map((id) => sql`${id}`), sql`, `)}))`,
            ),
          )
          .orderBy(desc(timeTrackingAuditLog.createdAt))
          .limit(200)
      : [];

    return {
      summary: rowToSummary({
        ...row,
        daily_totals: (row.daily_totals ?? {}) as Record<string, number>,
        reviewed_by_label: null,
      }),
      entries: entryRows.map(
        (e): TimesheetEntry => ({
          id: e.id,
          brand_id: e.brand_id,
          field_worker_id: e.field_worker_id,
          worker_name: e.worker_name ?? "(unknown)",
          task_id: e.task_id,
          task_name: e.task_name,
          clock_in: e.clock_in.toISOString(),
          clock_out: e.clock_out ? e.clock_out.toISOString() : null,
          lunch_break_minutes: e.lunch_break_minutes,
          notes: e.notes,
          submitted_via: e.submitted_via,
          entry_kind: e.entry_kind,
          manual_reason: e.manual_reason,
          gps_verified: e.gps_verified,
          clock_in_lat: e.clock_in_lat,
          clock_in_lng: e.clock_in_lng,
          clock_in_accuracy_m: e.clock_in_accuracy_m,
          clock_out_lat: e.clock_out_lat,
          clock_out_lng: e.clock_out_lng,
          clock_out_accuracy_m: e.clock_out_accuracy_m,
          edited_at: e.edited_at ? e.edited_at.toISOString() : null,
          edited_by_label: null,
          edit_reason: e.edit_reason,
          total_minutes: computeMinutes(
            e.clock_in,
            e.clock_out,
            e.lunch_break_minutes,
          ),
        }),
      ),
      audit: auditRows.map((a) => ({
        id: a.id,
        actor_id: a.actorId,
        actor_label: a.actorLabel,
        actor_kind: a.actorKind,
        action: a.action,
        entity_type: a.entityType,
        entity_id: a.entityId,
        details: (a.details as Record<string, unknown>) ?? {},
        created_at: a.createdAt.toISOString(),
      })),
    };
  });
}

function endOfDay(iso: string): Date {
  const d = new Date(iso);
  d.setHours(23, 59, 59, 999);
  return d;
}

function computeMinutes(
  clockIn: Date,
  clockOut: Date | null,
  lunchMinutes: number,
): number {
  if (!clockOut) return 0;
  return Math.max(
    0,
    Math.round((clockOut.getTime() - clockIn.getTime()) / 60000) - lunchMinutes,
  );
}

// ── Ensure the timesheet exists for a (worker, period) ────────────────────

export async function ensureTimesheetForPeriod(
  brandId: string,
  workerId: string,
  periodStart: string,
  periodEnd: string,
): Promise<string> {
  const caller = await resolveCaller(brandId);
  if (!caller) throw new Error("Not authenticated");

  const pool = getPool();
  const res = await pool.query<{ get_or_create_timesheet: string }>(
    "SELECT get_or_create_timesheet($1::uuid, $2::uuid, $3::date, $4::date) AS get_or_create_timesheet",
    [brandId, workerId, periodStart, periodEnd],
  );
  return res.rows[0]?.get_or_create_timesheet ?? "";
}

// ── Submit, approve, reject, unlock ────────────────────────────────────────

const SubmitSchema = z.object({
  timesheetId: z.string().uuid(),
  notes: z.string().max(1000).optional(),
});

export async function submitTimesheet(
  timesheetId: string,
  notes?: string,
): Promise<{ success: boolean; error?: string }> {
  const caller = await resolveCaller();
  if (!caller) return { success: false, error: "Not authenticated" };

  const parsed = SubmitSchema.safeParse({ timesheetId, notes });
  if (!parsed.success) return { success: false, error: "Invalid input" };

  return withTx(async (client) => {
    const ts = await client.query<{
      brand_id: string;
      field_worker_id: string;
      status: string;
    }>(
      `SELECT brand_id, field_worker_id, status
         FROM time_tracking_timesheets
        WHERE id = $1
        FOR UPDATE`,
      [timesheetId],
    );
    if (ts.rows.length === 0) return { success: false, error: "Not found" };
    const t = ts.rows[0];

    if (t.status !== "draft" && t.status !== "rejected") {
      return {
        success: false,
        error: `Cannot submit a timesheet in status '${t.status}'`,
      };
    }

    await client.query(
      `UPDATE time_tracking_timesheets
          SET status = 'submitted',
              submitted_at = NOW(),
              submitted_by = $2,
              submitted_notes = $3,
              rejected_at = NULL,
              rejected_by = NULL,
              rejection_reason = NULL,
              updated_at = NOW()
        WHERE id = $1`,
      [timesheetId, caller.adminUser.id, notes ?? null],
    );

    await logTimeTrackingEventInTx(client, {
      brandId: t.brand_id,
      actorId: caller.adminUser.id,
      actorLabel:
        caller.adminUser.display_name ?? caller.adminUser.email ?? "admin",
      action: "timesheet.submit",
      entityType: "timesheet",
      entityId: timesheetId,
      details: { notes: notes ?? null },
    });
    return { success: true };
  });
}

const ApprovalSchema = z.object({
  timesheetId: z.string().uuid(),
  comment: z.string().max(2000).optional(),
});

export async function approveTimesheet(
  timesheetId: string,
  comment?: string,
): Promise<{ success: boolean; error?: string }> {
  const caller = await resolveCaller();
  if (!caller) return { success: false, error: "Not authenticated" };
  if (
    caller.kind !== "platform_admin" &&
    caller.kind !== "brand_admin" &&
    caller.kind !== "supervisor"
  ) {
    return { success: false, error: "Not authorized" };
  }

  const parsed = ApprovalSchema.safeParse({ timesheetId, comment });
  if (!parsed.success) return { success: false, error: "Invalid input" };

  return withTx(async (client) => {
    const ts = await client.query<{
      brand_id: string;
      field_worker_id: string;
      status: string;
    }>(
      `SELECT brand_id, field_worker_id, status
         FROM time_tracking_timesheets
        WHERE id = $1
        FOR UPDATE`,
      [timesheetId],
    );
    if (ts.rows.length === 0) return { success: false, error: "Not found" };
    const t = ts.rows[0];

    // Supervisor must be assigned to this worker
    if (caller.kind === "supervisor" && caller.supervisorFieldWorkerId) {
      const ok = await client.query(
        `SELECT 1 FROM time_tracking_supervisor_assignments
          WHERE supervisor_field_worker_id = $1
            AND supervisee_field_worker_id = $2
          LIMIT 1`,
        [caller.supervisorFieldWorkerId, t.field_worker_id],
      );
      if (ok.rows.length === 0)
        return { success: false, error: "Not authorized for this worker" };
    }

    if (t.status !== "submitted") {
      return {
        success: false,
        error: `Only submitted timesheets can be approved (status='${t.status}')`,
      };
    }

    const now = new Date();
    await client.query(
      `UPDATE time_tracking_timesheets
          SET status = 'approved',
              reviewed_at = $2,
              reviewed_by = $3,
              reviewer_comment = $4,
              locked_at = $2,
              locked_by = $3,
              updated_at = NOW()
        WHERE id = $1`,
      [timesheetId, now, caller.adminUser.id, comment ?? null],
    );

    await logTimeTrackingEventInTx(client, {
      brandId: t.brand_id,
      actorId: caller.adminUser.id,
      actorLabel:
        caller.adminUser.display_name ?? caller.adminUser.email ?? "admin",
      action: "timesheet.approve",
      entityType: "timesheet",
      entityId: timesheetId,
      details: { comment: comment ?? null },
    });

    // Recompute totals so the locked snapshot is accurate
    await client.query("SELECT recompute_timesheet_totals($1)", [timesheetId]);

    return { success: true };
  });
}

const RejectSchema = z.object({
  timesheetId: z.string().uuid(),
  reason: z.string().min(3).max(2000),
});

export async function rejectTimesheet(
  timesheetId: string,
  reason: string,
): Promise<{ success: boolean; error?: string }> {
  const caller = await resolveCaller();
  if (!caller) return { success: false, error: "Not authenticated" };
  if (
    caller.kind !== "platform_admin" &&
    caller.kind !== "brand_admin" &&
    caller.kind !== "supervisor"
  ) {
    return { success: false, error: "Not authorized" };
  }

  const parsed = RejectSchema.safeParse({ timesheetId, reason });
  if (!parsed.success) return { success: false, error: "Reason is required" };

  return withTx(async (client) => {
    const ts = await client.query<{
      brand_id: string;
      field_worker_id: string;
      status: string;
    }>(
      `SELECT brand_id, field_worker_id, status
         FROM time_tracking_timesheets
        WHERE id = $1
        FOR UPDATE`,
      [timesheetId],
    );
    if (ts.rows.length === 0) return { success: false, error: "Not found" };
    const t = ts.rows[0];

    if (caller.kind === "supervisor" && caller.supervisorFieldWorkerId) {
      const ok = await client.query(
        `SELECT 1 FROM time_tracking_supervisor_assignments
          WHERE supervisor_field_worker_id = $1
            AND supervisee_field_worker_id = $2
          LIMIT 1`,
        [caller.supervisorFieldWorkerId, t.field_worker_id],
      );
      if (ok.rows.length === 0)
        return { success: false, error: "Not authorized" };
    }

    if (t.status !== "submitted") {
      return {
        success: false,
        error: `Only submitted timesheets can be rejected (status='${t.status}')`,
      };
    }

    await client.query(
      `UPDATE time_tracking_timesheets
          SET status = 'rejected',
              rejected_at = NOW(),
              rejected_by = $2,
              rejection_reason = $3,
              locked_at = NULL,
              locked_by = NULL,
              updated_at = NOW()
        WHERE id = $1`,
      [timesheetId, caller.adminUser.id, reason],
    );

    await logTimeTrackingEventInTx(client, {
      brandId: t.brand_id,
      actorId: caller.adminUser.id,
      actorLabel:
        caller.adminUser.display_name ?? caller.adminUser.email ?? "admin",
      action: "timesheet.reject",
      entityType: "timesheet",
      entityId: timesheetId,
      details: { reason },
    });

    return { success: true };
  });
}

const UnlockSchema = z.object({
  timesheetId: z.string().uuid(),
  auditNote: z.string().min(5).max(2000),
});

export async function unlockTimesheet(
  timesheetId: string,
  auditNote: string,
): Promise<{ success: boolean; error?: string }> {
  const caller = await resolveCaller();
  if (!caller) return { success: false, error: "Not authenticated" };

  // Only platform_admin or brand_admin can unlock a locked timesheet.
  if (caller.kind !== "platform_admin" && caller.kind !== "brand_admin") {
    return {
      success: false,
      error: "Only admins can unlock a locked timesheet",
    };
  }

  const parsed = UnlockSchema.safeParse({ timesheetId, auditNote });
  if (!parsed.success)
    return {
      success: false,
      error: "An audit note of at least 5 characters is required",
    };

  return withTx(async (client) => {
    const ts = await client.query<{
      brand_id: string;
      field_worker_id: string;
      status: string;
      locked_at: Date | null;
    }>(
      `SELECT brand_id, field_worker_id, status, locked_at
         FROM time_tracking_timesheets
        WHERE id = $1
        FOR UPDATE`,
      [timesheetId],
    );
    if (ts.rows.length === 0) return { success: false, error: "Not found" };
    const t = ts.rows[0];

    if (!t.locked_at) {
      return { success: false, error: "Timesheet is not currently locked" };
    }

    await client.query(
      `UPDATE time_tracking_timesheets
          SET status = 'draft',
              locked_at = NULL,
              locked_by = NULL,
              unlocked_at = NOW(),
              unlocked_by = $2,
              unlock_audit_note = $3,
              updated_at = NOW()
        WHERE id = $1`,
      [timesheetId, caller.adminUser.id, auditNote],
    );

    await logTimeTrackingEventInTx(client, {
      brandId: t.brand_id,
      actorId: caller.adminUser.id,
      actorLabel:
        caller.adminUser.display_name ?? caller.adminUser.email ?? "admin",
      action: "timesheet.unlock",
      entityType: "timesheet",
      entityId: timesheetId,
      details: { audit_note: auditNote },
    });

    return { success: true };
  });
}

// ── Helpers for client components ──────────────────────────────────────────

/** Compute and return the [start, end] of the current pay period for a brand. */
export async function getCurrentPayPeriod(
  brandId: string,
): Promise<{ start: string; end: string }> {
  const { getTimeTrackingSettings } = await import("./index");
  const settings = await getTimeTrackingSettings(brandId);
  const { start, end } = payPeriodForDate(new Date(), settings);
  return { start: toIsoDate(start), end: toIsoDate(end) };
}