import Testing

@testable import NorgKeyboardToolbar

struct EditorSnippetTests {

  @Test func idMatchesRawValueAndIsUnique() {
    for snippet in EditorSnippet.allCases {
      #expect(snippet.id == snippet.rawValue)
    }
    #expect(Set(EditorSnippet.allCases.map(\.id)).count == EditorSnippet.allCases.count)
  }

  @Test func insertsIntoEmptyDocumentWithoutLeadingNewline() {
    let result = EditorSnippet.heading.apply(to: "", cursor: 0)
    #expect(result.text == "* ")
    #expect(result.cursor == 2)
  }

  @Test func insertsOnNewLineBeneathCurrentLine() {
    let result = EditorSnippet.task.apply(to: "first line", cursor: 3)
    #expect(result.text == "first line\n- ( ) ")
    // Cursor sits at the end of the inserted task marker, ready to type.
    #expect(result.cursor == result.text.count)
  }

  @Test func insertsBetweenLinesNotSplittingThem() {
    let result = EditorSnippet.task.apply(to: "a\nb", cursor: 0)
    #expect(result.text == "a\n- ( ) \nb")
  }

  @Test func delimiterHasNoTrailingSpace() {
    let weak = EditorSnippet.weakReverse.apply(to: "x", cursor: 1)
    #expect(weak.text == "x\n---")
    let strong = EditorSnippet.strongReverse.apply(to: "x", cursor: 1)
    #expect(strong.text == "x\n===")
  }

  @Test func codeBlockPlacesCursorIndentedBetweenMarkers() {
    let result = EditorSnippet.code.apply(to: "note", cursor: 4)
    #expect(result.text == "note\n@code\n\t\n@end")
    // Cursor lands right after the tab on the middle line.
    let index = result.text.index(result.text.startIndex, offsetBy: result.cursor)
    #expect(result.text[result.text.startIndex..<index].hasSuffix("@code\n\t"))
    #expect(String(result.text[index...]) == "\n@end")
  }

  @Test func clampsCursorBeyondBounds() {
    let result = EditorSnippet.heading.apply(to: "abc", cursor: 999)
    #expect(result.text == "abc\n* ")
  }

  // MARK: - Heading promotion (the `*` button's special behaviour)

  @Test func headingPromotesEmptyMarker() {
    // "* |" -> "** |"
    let result = EditorSnippet.heading.apply(to: "* ", cursor: 2)
    #expect(result.text == "** ")
    #expect(result.cursor == 3)
  }

  @Test func headingPromotesWithTrailingContent() {
    // "* |Hello" -> "** |Hello"
    let result = EditorSnippet.heading.apply(to: "* Hello", cursor: 2)
    #expect(result.text == "** Hello")
    #expect(result.cursor == 3)
  }

  @Test func headingPromotesBareStars() {
    // "***|" -> "****|"
    let result = EditorSnippet.heading.apply(to: "***", cursor: 3)
    #expect(result.text == "****")
    #expect(result.cursor == 4)
  }

  @Test func headingInsertsNewLineWhenCursorAfterContent() {
    // "* Hello|" -> new heading line
    let result = EditorSnippet.heading.apply(to: "* Hello", cursor: 7)
    #expect(result.text == "* Hello\n* ")
  }

  @Test func headingInsertsNewLineWhenMarkerNotAtLineStart() {
    // "Hello *|" -> new heading line, not promotion
    let result = EditorSnippet.heading.apply(to: "Hello *", cursor: 7)
    #expect(result.text == "Hello *\n* ")
  }

  @Test func headingPromotesIndentedMarker() {
    let result = EditorSnippet.heading.apply(to: "  ** ", cursor: 5)
    #expect(result.text == "  *** ")
  }

  @Test func headingPromotionKeepsCursorWhenInsertingAfterIt() {
    // "*|*" -> "**|*" : the new star lands after the cursor, so the offset
    // is unchanged.
    let result = EditorSnippet.heading.apply(to: "**", cursor: 1)
    #expect(result.text == "***")
    #expect(result.cursor == 1)
  }

  // MARK: - Task button heading awareness

  @Test func taskAddsMarkerToBareHeading() {
    // "* |" -> "* ( ) |"
    let result = EditorSnippet.task.apply(to: "* ", cursor: 2)
    #expect(result.text == "* ( ) ")
    #expect(result.cursor == 6)
  }

  @Test func taskAddsMarkerToHeadingPreservingLevelAndContent() {
    // "** |Hello" -> "** ( ) |Hello"
    let result = EditorSnippet.task.apply(to: "** Hello", cursor: 3)
    #expect(result.text == "** ( ) Hello")
    #expect(result.cursor == 7)
  }

  @Test func taskInsertsNewLineWhenHeadingHasContent() {
    // "** Hello|" -> "** Hello\n- ( ) "
    let result = EditorSnippet.task.apply(to: "** Hello", cursor: 8)
    #expect(result.text == "** Hello\n- ( ) ")
    #expect(result.cursor == result.text.count)
  }

  @Test func taskAddsMarkerToBareOrderedListItem() {
    // "~ |" -> "~ ( ) |"
    let result = EditorSnippet.task.apply(to: "~ ", cursor: 2)
    #expect(result.text == "~ ( ) ")
    #expect(result.cursor == 6)
  }

  @Test func taskAddsMarkerToOrderedListPreservingLevelAndContent() {
    // "~~ |Hello" -> "~~ ( ) |Hello"
    let result = EditorSnippet.task.apply(to: "~~ Hello", cursor: 3)
    #expect(result.text == "~~ ( ) Hello")
    #expect(result.cursor == 7)
  }

  @Test func taskInsertsNewLineWhenOrderedListHasContent() {
    // "~ Hello|" -> "~ Hello\n- ( ) "
    let result = EditorSnippet.task.apply(to: "~ Hello", cursor: 7)
    #expect(result.text == "~ Hello\n- ( ) ")
    #expect(result.cursor == result.text.count)
  }

  @Test func headingIgnoresOrderedListMarker() {
    // The `*` button only promotes `*` headings, not `~` lists.
    let result = EditorSnippet.heading.apply(to: "~ ", cursor: 2)
    #expect(result.text == "~ \n* ")
  }
}