(** Example: Validating JSON Feeds

    This demonstrates:
    - Validating feed structure
    - Testing various edge cases
    - Handling invalid feeds
    - Best practices for feed construction *)

open Jsonfeed

let test_valid_minimal_feed () =
  Format.printf "=== Test: Minimal Valid Feed ===\n";

  let feed = Jsonfeed.create
    ~title:"Minimal Feed"
    ~items:[]
    () in

  match Jsonfeed.validate feed with
  | Ok () -> Format.printf "✓ Minimal feed is valid\n\n"
  | Error errors ->
      Format.printf "✗ Minimal feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_valid_complete_feed () =
  Format.printf "=== Test: Complete Valid Feed ===\n";

  let author = Author.create
    ~name:"Test Author"
    ~url:"https://example.com/author"
    ~avatar:"https://example.com/avatar.png"
    () in

  let attachment = Attachment.create
    ~url:"https://example.com/file.mp3"
    ~mime_type:"audio/mpeg"
    ~title:"Audio File"
    ~size_in_bytes:1024L
    ~duration_in_seconds:60
    () in

  let item = Item.create
    ~id:"https://example.com/items/1"
    ~url:"https://example.com/items/1"
    ~title:"Test Item"
    ~content:(`Both ("<p>HTML content</p>", "Text content"))
    ~summary:"A test item"
    ~image:"https://example.com/image.jpg"
    ~banner_image:"https://example.com/banner.jpg"
    ~date_published:(Jsonfeed.parse_rfc3339 "2024-11-01T10:00:00Z" |> Option.get)
    ~date_modified:(Jsonfeed.parse_rfc3339 "2024-11-01T15:00:00Z" |> Option.get)
    ~authors:[author]
    ~tags:["test"; "example"]
    ~language:"en"
    ~attachments:[attachment]
    () in

  let hub = Hub.create
    ~type_:"WebSub"
    ~url:"https://pubsubhubbub.appspot.com/"
    () in

  let feed = Jsonfeed.create
    ~title:"Complete Feed"
    ~home_page_url:"https://example.com"
    ~feed_url:"https://example.com/feed.json"
    ~description:"A complete test feed"
    ~user_comment:"This is a test feed"
    ~icon:"https://example.com/icon.png"
    ~favicon:"https://example.com/favicon.ico"
    ~authors:[author]
    ~language:"en-US"
    ~hubs:[hub]
    ~items:[item]
    () in

  match Jsonfeed.validate feed with
  | Ok () -> Format.printf "✓ Complete feed is valid\n\n"
  | Error errors ->
      Format.printf "✗ Complete feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_feed_with_multiple_items () =
  Format.printf "=== Test: Feed with Multiple Items ===\n";

  let items = List.init 10 (fun i ->
    Item.create
      ~id:(Printf.sprintf "https://example.com/items/%d" i)
      ~content:(`Text (Printf.sprintf "Item %d content" i))
      ~title:(Printf.sprintf "Item %d" i)
      ~date_published:(Jsonfeed.parse_rfc3339
        (Printf.sprintf "2024-11-%02dT10:00:00Z" (i + 1)) |> Option.get)
      ()
  ) in

  let feed = Jsonfeed.create
    ~title:"Multi-item Feed"
    ~items
    () in

  match Jsonfeed.validate feed with
  | Ok () ->
      Format.printf "✓ Feed with %d items is valid\n\n" (List.length items)
  | Error errors ->
      Format.printf "✗ Multi-item feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_podcast_feed () =
  Format.printf "=== Test: Podcast Feed ===\n";

  let host = Author.create
    ~name:"Podcast Host"
    ~url:"https://podcast.example.com/host"
    () in

  let episode1 = Attachment.create
    ~url:"https://podcast.example.com/ep1.mp3"
    ~mime_type:"audio/mpeg"
    ~title:"Episode 1"
    ~size_in_bytes:20_971_520L  (* 20 MB *)
    ~duration_in_seconds:1800    (* 30 minutes *)
    () in

  (* Alternate format of the same episode *)
  let episode1_aac = Attachment.create
    ~url:"https://podcast.example.com/ep1.aac"
    ~mime_type:"audio/aac"
    ~title:"Episode 1"
    ~size_in_bytes:16_777_216L
    ~duration_in_seconds:1800
    () in

  let item = Item.create
    ~id:"https://podcast.example.com/episodes/1"
    ~url:"https://podcast.example.com/episodes/1"
    ~title:"Episode 1: Introduction"
    ~content:(`Html "<p>Welcome to the first episode!</p>")
    ~date_published:(Jsonfeed.parse_rfc3339 "2024-11-01T12:00:00Z" |> Option.get)
    ~authors:[host]
    ~attachments:[episode1; episode1_aac]
    ~image:"https://podcast.example.com/ep1-cover.jpg"
    () in

  let feed = Jsonfeed.create
    ~title:"Example Podcast"
    ~home_page_url:"https://podcast.example.com"
    ~feed_url:"https://podcast.example.com/feed.json"
    ~authors:[host]
    ~items:[item]
    () in

  match Jsonfeed.validate feed with
  | Ok () -> Format.printf "✓ Podcast feed is valid\n\n"
  | Error errors ->
      Format.printf "✗ Podcast feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_microblog_feed () =
  Format.printf "=== Test: Microblog Feed (no titles) ===\n";

  let author = Author.create
    ~name:"Microblogger"
    ~url:"https://micro.example.com"
    () in

  let items = [
    Item.create
      ~id:"https://micro.example.com/1"
      ~content:(`Text "Just posted a new photo!")
      ~date_published:(Jsonfeed.parse_rfc3339 "2024-11-01T08:00:00Z" |> Option.get)
      ();
    Item.create
      ~id:"https://micro.example.com/2"
      ~content:(`Text "Having a great day! ☀️")
      ~date_published:(Jsonfeed.parse_rfc3339 "2024-11-01T12:30:00Z" |> Option.get)
      ();
    Item.create
      ~id:"https://micro.example.com/3"
      ~content:(`Html "<p>Check out this <a href=\"#\">link</a></p>")
      ~date_published:(Jsonfeed.parse_rfc3339 "2024-11-01T16:45:00Z" |> Option.get)
      ()
  ] in

  let feed = Jsonfeed.create
    ~title:"Microblog"
    ~home_page_url:"https://micro.example.com"
    ~authors:[author]
    ~items
    () in

  match Jsonfeed.validate feed with
  | Ok () ->
      Format.printf "✓ Microblog feed with %d items is valid\n\n"
        (List.length items)
  | Error errors ->
      Format.printf "✗ Microblog feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_expired_feed () =
  Format.printf "=== Test: Expired Feed ===\n";

  let feed = Jsonfeed.create
    ~title:"Archived Blog"
    ~home_page_url:"https://archive.example.com"
    ~description:"This blog is no longer updated"
    ~expired:true
    ~items:[]
    () in

  match Jsonfeed.validate feed with
  | Ok () -> Format.printf "✓ Expired feed is valid\n\n"
  | Error errors ->
      Format.printf "✗ Expired feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_paginated_feed () =
  Format.printf "=== Test: Paginated Feed ===\n";

  let items = List.init 25 (fun i ->
    Item.create
      ~id:(Printf.sprintf "https://example.com/items/%d" i)
      ~content:(`Text (Printf.sprintf "Item %d" i))
      ()
  ) in

  let feed = Jsonfeed.create
    ~title:"Large Feed"
    ~home_page_url:"https://example.com"
    ~feed_url:"https://example.com/feed.json?page=1"
    ~next_url:"https://example.com/feed.json?page=2"
    ~items
    () in

  match Jsonfeed.validate feed with
  | Ok () ->
      Format.printf "✓ Paginated feed is valid (page 1 with next_url)\n\n"
  | Error errors ->
      Format.printf "✗ Paginated feed validation failed:\n";
      List.iter (Format.printf "  - %s\n") errors;
      Format.printf "\n"

let test_invalid_feed_from_json () =
  Format.printf "=== Test: Parsing Invalid JSON ===\n";

  (* Missing required version field *)
  let invalid_json1 = {|{
    "title": "Test",
    "items": []
  }|} in

  (match Jsonfeed.of_string invalid_json1 with
   | Ok _ -> Format.printf "✗ Should have failed (missing version)\n"
   | Error (`Msg err) ->
       Format.printf "✓ Correctly rejected invalid feed: %s\n" err);

  (* Missing required title field *)
  let invalid_json2 = {|{
    "version": "https://jsonfeed.org/version/1.1",
    "items": []
  }|} in

  (match Jsonfeed.of_string invalid_json2 with
   | Ok _ -> Format.printf "✗ Should have failed (missing title)\n"
   | Error (`Msg err) ->
       Format.printf "✓ Correctly rejected invalid feed: %s\n" err);

  (* Item without id *)
  let invalid_json3 = {|{
    "version": "https://jsonfeed.org/version/1.1",
    "title": "Test",
    "items": [{
      "content_text": "Hello"
    }]
  }|} in

  (match Jsonfeed.of_string invalid_json3 with
   | Ok _ -> Format.printf "✗ Should have failed (item without id)\n"
   | Error (`Msg err) ->
       Format.printf "✓ Correctly rejected invalid feed: %s\n" err);

  Format.printf "\n"

let main () =
  Format.printf "\n=== JSON Feed Validation Tests ===\n\n";

  test_valid_minimal_feed ();
  test_valid_complete_feed ();
  test_feed_with_multiple_items ();
  test_podcast_feed ();
  test_microblog_feed ();
  test_expired_feed ();
  test_paginated_feed ();
  test_invalid_feed_from_json ();

  Format.printf "=== All Tests Complete ===\n"

let () = main ()