fix: show an error for invalid pages

src/error.rs

@@ -8,6 +8,8 @@ pub enum Error {
   MissingElement(String),
   #[fail(display = "the content scraped from the Lodestone was invalid: {}", _0)]
   InvalidContent(String),
+  #[fail(display = "invalid page (1 through {} available)", _0)]
+  InvalidPage(u64),
 
   #[fail(display = "invalid number: {}", _0)]
   InvalidNumber(std::num::ParseIntError),

src/logic/search.rs

@@ -21,6 +21,8 @@ selectors!(
 );
 
 crate fn parse_pagination(html: &Html) -> Result<Pagination> {
+  const LODESTONE_PER_PAGE: f32 = 50.0;
+
   let total_str = crate::logic::plain_parse(&html, &*PAGINATION_TOTAL)?;
   let total_results: u64 = total_str
     .split(' ')
@@ -29,20 +31,27 @@ crate fn parse_pagination(html: &Html) -> Result<Pagination> {
     .parse()
     .map_err(Error::InvalidNumber)?;
 
-  let pages_str = crate::logic::plain_parse(&html, &*PAGINATION_PAGES)?;
-  let mut pages_split = pages_str.split(' ');
+  let (total_pages, current_page) = if parse_no_results(html) {
+    let total_pages = (total_results as f32 / LODESTONE_PER_PAGE).ceil() as u64;
+    let current_page = 0;
+    (total_pages, current_page)
+  } else {
+    let pages_str = crate::logic::plain_parse(&html, &*PAGINATION_PAGES)?;
+    let mut pages_split = pages_str.split(' ');
 
-  let current_page: u64 = pages_split
-    .nth(1)
-    .ok_or_else(|| Error::invalid_content("4 items in pages string", None))?
-    .parse()
-    .map_err(Error::InvalidNumber)?;
+    let current_page: u64 = pages_split
+      .nth(1)
+      .ok_or_else(|| Error::invalid_content("4 items in pages string", None))?
+      .parse()
+      .map_err(Error::InvalidNumber)?;
 
-  let total_pages: u64 = pages_split
-    .nth(1)
-    .ok_or_else(|| Error::invalid_content("4 items in pages string", None))?
-    .parse()
-    .map_err(Error::InvalidNumber)?;
+    let total_pages: u64 = pages_split
+      .nth(1)
+      .ok_or_else(|| Error::invalid_content("4 items in pages string", None))?
+      .parse()
+      .map_err(Error::InvalidNumber)?;
+    (total_pages, current_page)
+  };
 
   Ok(Pagination {
     current_page,

src/logic/search/character.rs

@@ -32,15 +32,13 @@ selectors!(
 pub fn parse(html: &str) -> Result<Paginated<CharacterSearchItem>> {
   let html = Html::parse_document(html);
 
-  if crate::logic::search::parse_no_results(&html) {
-    return Ok(Paginated {
-      pagination: Default::default(),
-      results: Default::default(),
-    });
-  }
-
   let pagination = crate::logic::search::parse_pagination(&html)?;
 
+  // has results but requested an invalid page
+  if pagination.total_results != 0 && pagination.current_page == 0 {
+    return Err(Error::InvalidPage(pagination.total_pages));
+  }
+
   let results: Vec<CharacterSearchItem> = html
     .select(&*ITEM_ENTRY)
     .map(|x| parse_single(x))

src/logic/search/free_company.rs

@@ -38,15 +38,13 @@ selectors!(
 pub fn parse(s: &str) -> Result<Paginated<FreeCompanySearchItem>> {
   let html = Html::parse_document(s);
 
-  if crate::logic::search::parse_no_results(&html) {
-    return Ok(Paginated {
-      pagination: Default::default(),
-      results: Default::default(),
-    });
-  }
-
   let pagination = crate::logic::search::parse_pagination(&html)?;
 
+  // has results but requested an invalid page
+  if pagination.total_results != 0 && pagination.current_page == 0 {
+    return Err(Error::InvalidPage(pagination.total_pages));
+  }
+
   let results: Vec<FreeCompanySearchItem> = html
     .select(&*ITEM_ENTRY)
     .map(|x| parse_single(x))