fix: add defensive checks for queue emptiness and add queue cleanup functions

R/dashboard_module_address_entry.R

@@ -142,6 +142,16 @@ observe_address_validation <- function(input, session, db, current_case, jwt, ap
 
   observeEvent(input$address_validate, {
     logger::log_debug("Address validation button pressed")
+
+    # Check if we have a valid case
+    case_id <- current_case()
+    if (is.null(case_id) || is.na(case_id)) {
+      showModal(modalDialog(
+        title = "No Case Available",
+        "No case is currently available for address validation. Please refresh to get a new case."
+      ))
+      return()
+    }
 
     address_entered$object <- isolate_address_entered(input)
     address_entered$string <- stringify_address_entered(address_entered$object)
@@ -214,7 +224,7 @@ observe_address_validation <- function(input, session, db, current_case, jwt, ap
       } else {
         modal_content <- "Could not validate address."
 
-        query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {current_case()};', .con = db)
+        query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {case_id};', .con = db)
         logger::log_debug("Query: {query}")
 
         DBI::dbExecute(
@@ -226,7 +236,7 @@ observe_address_validation <- function(input, session, db, current_case, jwt, ap
     } else {
       modal_content <- "Bad response from validation server"
 
-      query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {current_case()};', .con = db)
+      query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {case_id};', .con = db)
       logger::log_debug("Query: {query}")
 
       DBI::dbExecute(
@@ -346,14 +356,19 @@ observe_address_submission <- function(input, db, current_case, current_user, ad
   observeEvent(input$address_submit, {
     logger::log_debug("Address submit button pressed")
 
-    current_case <- current_case()
+    case_id <- current_case()
+
+    # Check if we have a valid case
+    if (is.null(case_id) || is.na(case_id)) {
+      rlang::abort("Cannot submit address: no valid case is available.")
+    }
 
     if(is.null(address_validated$object)) {
       rlang::abort("Something is wrong. You submitted an address without first validating.")
     }
 
     new_row <- tibble::tibble(
-      case = current_case(),
+      case = case_id,
       street_number = as.character(address_validated$object$streetNumber),
       street_direction = as.character(address_validated$object$streetDirection),
       street_name = as.character(address_validated$object$streetName),
@@ -399,7 +414,7 @@ observe_address_submission <- function(input, db, current_case, current_user, ad
       logger::log_debug("Wrote new record in 'address' table")
 
       pool::poolWithTransaction(db, function(conn) {
-        query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET success = TRUE, working = FALSE, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {current_case()};', .con = conn)
+        query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET success = TRUE, working = FALSE, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {case_id};', .con = conn)
 
         DBI::dbExecute(
           conn = conn,
@@ -409,7 +424,7 @@ observe_address_submission <- function(input, db, current_case, current_user, ad
 
         # Create a new row in the process_log table associating this address with the current user
         new_row <- tibble::tibble(
-          case = current_case(),
+          case = case_id,
           user = current_user(),
           created_at = lubridate::now(tzone = "America/Chicago"),
           updated_at = lubridate::now(tzone = "America/Chicago")
@@ -432,7 +447,7 @@ observe_address_submission <- function(input, db, current_case, current_user, ad
     } else {
       logger::log_error("Failed to write the new record to table 'address'")
 
-      query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, working = FALSE, success = FALSE, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {current_case()};', .con = db)
+      query <- glue::glue_sql('UPDATE "eviction_addresses"."queue" SET attempts = attempts + 1, working = FALSE, success = FALSE, stopped_at = CURRENT_TIMESTAMP WHERE "case" = {case_id};', .con = db)
 
       update_res <- DBI::dbExecute(
         conn = db,

R/dashboard_module_current_documents.R

@@ -36,7 +36,14 @@ currentDocumentsUI <- function(id) {
 currentDocumentsServer <- function(id, current_case, db) {
   moduleServer(id, function(input, output, session) {
     documents <- reactive({
-      res <- get_documents_by_case(db = db, id = current_case())
+      case_id <- current_case()
+
+      # Return empty data frame if no case is available
+      if (is.null(case_id) || is.na(case_id)) {
+        return(data.frame())
+      }
+
+      res <- get_documents_by_case(db = db, id = case_id)
       logger::log_debug("Documents retrieved: {res}")
       res
     })

R/dashboard_module_entry_detail.R

@@ -30,8 +30,19 @@ entryDetailUI <- function(id) {
 entryDetailServer <- function(id, current_case, total_cases) {
   moduleServer(id, function(input, output, session) {
     output$current_case_ui <- renderUI({
-      current_case <- jsonlite::fromJSON(current_case())
+      case_json <- current_case()
       queue <- total_cases()
+
+      # Handle empty queue - cases unavailable for processing
+      if (is.null(case_json) || length(case_json) == 0 || is.na(case_json) || (case_json == "")) {
+        return(div(
+          h4("No cases available for processing"),
+          h4(glue::glue("{queue} total in queue"))
+        ))
+      }
+
+      # Parse JSON and display valid case
+      current_case <- jsonlite::fromJSON(case_json)
       div(
         h4(glue::glue("Current case: {current_case$case_number}")),
         h4(glue::glue("{queue} cases in queue"))

R/dashboard_server.R

@@ -100,6 +100,11 @@ dashboard_server <- function(config) {
     documents <- reactive({
       current_case <- current_case()
 
+      # Return NULL if no case is available (queue is empty)
+      if (is.null(current_case) || is.na(current_case)) {
+        return(NULL)
+      }
+
       res <- get_documents_by_case(db = db, id = current_case)
 
       res

R/queue.R

@@ -44,12 +44,11 @@ get_queue_length <- function(db, status = "available") {
 #'
 #'
 clean_queue <- function(db) {
-  ## Remove any queue rows where success is true and it's 2 weeks old
-  ## ? Should we check whether the address is found in the db ?
+  ## Remove any queue rows where success is true
 
-  query <- dbplyr::sql("DELETE FROM eviction_addresses.queue WHERE success IS TRUE AND created_at < current_timestamp - interval '14 days';")
+  query <- dbplyr::sql("DELETE FROM eviction_addresses.queue WHERE success IS TRUE;")
   num_deleted_queue_rows <- DBI::dbExecute(db, query)
-  logger::log_debug("{num_deleted_queue_rows} rows deleted")
+  logger::log_info("{num_deleted_queue_rows} completed rows deleted from queue")
 
   return()
 }
@@ -114,6 +113,12 @@ get_case_from_queue <- function(db) {
       conn,
       dbplyr::sql('SELECT q."case" FROM eviction_addresses.queue q LEFT JOIN eviction_addresses."case" c ON q."case" = c."id" LEFT JOIN public."case" pc ON q."case" = pc.id WHERE "success" IS NOT TRUE AND "working" IS NOT TRUE ORDER BY attempts ASC, pc.status DESC, c.date_filed DESC LIMIT 1 FOR UPDATE OF q SKIP LOCKED;')
     )
+
+    # Return NULL if no cases available in queue
+    if (nrow(case) == 0) {
+      return(NULL)
+    }
+
     query <- glue::glue_sql(
       'UPDATE "eviction_addresses"."queue" SET working = TRUE, started_at = CURRENT_TIMESTAMP, stopped_at = NULL WHERE "case" = {case}',
       .con = conn
@@ -126,3 +131,61 @@ get_case_from_queue <- function(db) {
   })
 
 }
+
+
+#' @title Reset Stuck Queue Items
+#'
+#' @description
+#' Resets queue items that have been stuck in 'working' status for over an hour.
+#' These are typically cases from crashed or abandoned sessions.
+#' Items that exceed max retry attempts (3) are logged but not reset.
+#'
+#' @param db A database connection
+#' @param max_retries Maximum number of retry attempts before giving up on a case. Defaults to 3.
+#' @param stale_threshold_hours Number of hours before a working case is considered stuck. Defaults to 1.
+#'
+#' @returns Nothing
+#'
+reset_stuck_queue_items <- function(db, max_retries = 3, stale_threshold_hours = 1) {
+  # Find stuck cases: working=TRUE and started over threshold hours ago
+  stuck_query <- glue::glue_sql(.con = db, "
+    SELECT \"case\", attempts 
+    FROM eviction_addresses.queue 
+    WHERE working = TRUE 
+      AND started_at < CURRENT_TIMESTAMP - INTERVAL '{stale_threshold_hours} hours';
+  ")
+
+  stuck_cases <- DBI::dbGetQuery(db, stuck_query)
+
+  if (nrow(stuck_cases) == 0) {
+    logger::log_info("No stuck queue items found")
+    return(invisible(NULL))
+  }
+
+  num_stuck <- nrow(stuck_cases)
+  num_max_retries <- sum(stuck_cases$attempts >= max_retries)
+  num_to_reset <- num_stuck - num_max_retries
+
+  # Reset cases that haven't exceeded max retries
+  if (num_to_reset > 0) {
+    reset_query <- glue::glue_sql(.con = db, "
+      UPDATE eviction_addresses.queue 
+      SET working = FALSE, 
+          attempts = attempts + 1, 
+          stopped_at = CURRENT_TIMESTAMP 
+      WHERE working = TRUE 
+        AND started_at < CURRENT_TIMESTAMP - INTERVAL '{stale_threshold_hours} hours'
+        AND attempts < {max_retries};
+    ")
+
+    num_reset <- DBI::dbExecute(db, reset_query)
+    logger::log_info("Reset {num_reset} stuck queue items (out of {num_stuck} total stuck)")
+  }
+
+  # Log cases that hit max retries
+  if (num_max_retries > 0) {
+    logger::log_warn("{num_max_retries} queue items reached max retry limit ({max_retries}) and will not be reset")
+  }
+
+  return(invisible(NULL))
+}

R/run_job.R

@@ -16,4 +16,5 @@ run_job <- function(config) {
     refresh_cases(db)
     refresh_minutes(db)
     refresh_queue(db)
+    reset_stuck_queue_items(db)
 }