//! `links::disarm` where the server's CommonMark parser and the clients' marked may read a reply
//! differently: such text is read as prose, so an image in it still goes in a code span (M5b
//! spec, section 9). Each case names the rule it pins. Do not edit.

use gatewayd::links::disarm;

/// (case, input, clean reply). The untrusted reply is checked by the tests in `links.rs`.
type Case = (&'static str, &'static str, &'static str);

const FENCES: &[Case] = &[
    (
        "an unclosed fence is prose",
        "```\n![i](https://e.example/a)",
        "```\n````![i](https://e.example/a)````",
    ),
    (
        "a closer may end with tildes, and what follows is prose",
        "```\n![i](https://e.example/a)\n```~\n![j](https://e.example/b)",
        "```\n![i](https://e.example/a)\n```~\n````![j](https://e.example/b)````",
    ),
    (
        "a longer closer closes, a shorter one does not",
        "```\n![i](https://e.example/a)\n````\n````\n```\n![j](https://e.example/b)\n````",
        "```\n![i](https://e.example/a)\n````\n````\n```\n![j](https://e.example/b)\n````",
    ),
    (
        "an opener indented four spaces is prose",
        "    ```\n    ![i](https://e.example/a)\n   ```",
        "    ```\n    ````![i](https://e.example/a)````\n   ```",
    ),
    (
        "two backticks are no fence",
        "``\n![i](https://e.example/a)\n``",
        "``\n```![i](https://e.example/a)```\n``",
    ),
    (
        "a closer indented four spaces does not close",
        "```\n![i](https://e.example/a)\n    ```\n![j](https://e.example/b)\n```",
        "```\n![i](https://e.example/a)\n    ```\n![j](https://e.example/b)\n```",
    ),
    (
        "an opener indented three spaces is a fence",
        "   ```\n   ![i](https://e.example/a)\n```",
        "   ```\n   ![i](https://e.example/a)\n```",
    ),
    (
        "an opener with a pipe after it is prose",
        "```|x\n![i](https://e.example/a)\n```",
        "```|x\n````![i](https://e.example/a)````\n```",
    ),
    (
        "an opener with a backtick after it is prose",
        "``` a`b\n![i](https://e.example/a)\n```",
        "``` a`b\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a fence continuing a list item is prose",
        "- item\n```\n![i](https://e.example/a)\n```",
        "- item\n```\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a fence continuing a quote is prose",
        "> quote\n```\n![i](https://e.example/a)\n```",
        "> quote\n```\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a fence continuing a numbered item is prose",
        "1. item\n```\n![i](https://e.example/a)\n```",
        "1. item\n```\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a fence after an empty line below a list is a fence, even with an empty line inside",
        "- item\n\n```\n![i](https://e.example/a)\n\nx\n```",
        "- item\n\n```\n![i](https://e.example/a)\n\nx\n```",
    ),
    (
        "a line indented less than the opener ends it",
        "- item\n\n  ```\n![i](https://e.example/a)\n  ```",
        "- item\n\n  ```\n````![i](https://e.example/a)````\n  ```",
    ),
    (
        "an empty line inside an indented fence does not end it",
        "- item\n\n  ```\n  one\n\n  ![i](https://e.example/a)\n  ```",
        "- item\n\n  ```\n  one\n\n  ![i](https://e.example/a)\n  ```",
    ),
    (
        "a fence after an HTML tag is prose",
        "<div>\n\n```\n![i](https://e.example/a)\n```\n\n</div>",
        "<div>\n\n```\n````![i](https://e.example/a)````\n```\n\n</div>",
    ),
    (
        "a tag after a list marker counts",
        "- <div>\n\n```\n![i](https://e.example/a)\n```",
        "- <div>\n\n```\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a tag inside a line does not",
        "Use `Vec<String>`:\n```\n![i](https://e.example/a)\n```",
        "Use `Vec<String>`:\n```\n![i](https://e.example/a)\n```",
    ),
    (
        "a closing tag counts",
        "</p>\n```\n![i](https://e.example/a)\n```",
        "</p>\n```\n````![i](https://e.example/a)````\n```",
    ),
    (
        "a tag after the fence does not matter",
        "```\n![i](https://e.example/a)\n```\n<div>",
        "```\n![i](https://e.example/a)\n```\n<div>",
    ),
    (
        "a tag inside a fence does not count",
        "```\n<div>\n```\n```\n![i](https://e.example/a)\n```",
        "```\n<div>\n```\n```\n![i](https://e.example/a)\n```",
    ),
];

const LINES: &[Case] = &[
    (
        "a carriage return ends a line",
        "```\r![i](https://e.example/a)\r```\rtext\r![j](https://e.example/b)",
        "```\r![i](https://e.example/a)\r```\rtext\r````![j](https://e.example/b)````",
    ),
    (
        "U+2424 ends a line",
        "```\u{2424}![i](https://e.example/a)\u{2424}```",
        "```\u{2424}![i](https://e.example/a)\u{2424}```",
    ),
    (
        "CRLF is one line end, not an empty line",
        "`a\r\n`![i](https://e.example/a)`",
        "`a\r\n` ``![i](https://e.example/a)`` `",
    ),
    (
        "a line of spaces inside an alt is written as it is",
        "![a\n \nb](https://e.example/x)",
        "`![a`\n \n`b](https://e.example/x)`",
    ),
    (
        "an alt split by CRLF keeps it",
        "![a\r\nb](https://e.example/x)",
        "`![a`\r\n`b](https://e.example/x)`",
    ),
];

const SPANS: &[Case] = &[
    (
        "a span on one line is code",
        "a\n`![i](https://e.example/a)`",
        "a\n`![i](https://e.example/a)`",
    ),
    (
        "after a lone backtick, a span of its length is prose",
        "`a\n`![i](https://e.example/a)`",
        "`a\n` ``![i](https://e.example/a)`` `",
    ),
    (
        "a span of another length is still code",
        "`a\n``![i](https://e.example/a)``",
        "`a\n``![i](https://e.example/a)``",
    ),
    (
        "a span holding a run of that length is prose",
        "`lone\n``a ` ![i](https://e.example/a) ``",
        "`lone\n``a ` ```![i](https://e.example/a)``` ``",
    ),
    (
        "an empty line starts afresh",
        "`a\n\n`![i](https://e.example/a)`",
        "`a\n\n`![i](https://e.example/a)`",
    ),
    (
        "a line of spaces does not",
        "`a\n \n`![i](https://e.example/a)`",
        "`a\n \n` ``![i](https://e.example/a)`` `",
    ),
    (
        "a span that does not close on its line is prose",
        "`a\nb` ![i](https://e.example/a)",
        "`a\nb` ``![i](https://e.example/a)``",
    ),
    (
        "a span holding a pipe is prose (a table cell ends there)",
        "| `x | ![i](https://e.example/a) | y` |",
        "| `x | ``![i](https://e.example/a)`` | y` |",
    ),
    (
        "an escaped backtick opens nothing",
        "\\`![i](https://e.example/a)`",
        "\\` ``![i](https://e.example/a)`` `",
    ),
    (
        "a backtick in a URL opens nothing (marked reads it as the URL's)",
        "https://x.example/a`b ![i](https://e.example/a) `",
        "https://x.example/a`b ``![i](https://e.example/a)`` `",
    ),
    (
        "a backtick in a link destination opens nothing",
        "[a](x `) ![i](https://e.example/a) `",
        "[a](x `) ``![i](https://e.example/a)`` `",
    ),
];

const BRACKETS: &[Case] = &[
    (
        "a label holding a bracket in code",
        "![a `]` b](https://e.example/a)",
        "``![a ``\\` ``]``\\` `` b](https://e.example/a)``",
    ),
    (
        "a label holding a lone backtick",
        "![a ``](https://e.example/a) `",
        "```![a ```\\`\\` ```](https://e.example/a)``` `",
    ),
    (
        "nested brackets and escapes in the label",
        "![a [b] \\] c](https://e.example/a)",
        "`![a [b] \\] c](https://e.example/a)`",
    ),
    (
        "nested parentheses in the destination; a backslash does not escape one",
        "![a](https://e.example/a_(b)\\)c) d",
        "`![a](https://e.example/a_(b)\\)`c) d",
    ),
    (
        "no parenthesis closes the destination",
        "![a](https://e.example/a b",
        "`![a]`(https://e.example/a b",
    ),
];

/// What marked lets take a backtick before a code span starts: emphasis, a tag, a URL, a link.
const STEALS: &[Case] = &[
    (
        "emphasis before a span that holds its closer makes it prose",
        "** `** ![i](https://e.example/a) `",
        "** `** ``![i](https://e.example/a)`` `",
    ),
    (
        "a tag before a span that holds a `>` makes it prose",
        "<b x='`'> ![i](https://e.example/a) `",
        "<b x='`'> ``![i](https://e.example/a)`` `",
    ),
    (
        "a `[` that starts no link is escaped when a `](` follows",
        "[x [y](https://l.example) and [z]",
        "\\[x [y](https://l.example) and [z]",
    ),
    (
        "the characters of a clean link count as seen",
        "[a*b](https://l.example) `*![i](https://e.example/a)`",
        "[a*b](https://l.example) `* ``![i](https://e.example/a)`` `",
    ),
    (
        "inline LaTeX before a span that holds a `$` makes it prose",
        "$a `$ ![i](https://e.example/a) `",
        "$a `$ ``![i](https://e.example/a)`` `",
    ),
    (
        "a new span splits at a `$` seen before it, which marked does not escape",
        "$x ![i](https://e.example/a$b)",
        "$x `![i](https://e.example/a`$ `b)`",
    ),
    (
        "but not at a `$` seen only after it",
        "![i](https://e.example/a$b) $x",
        "`![i](https://e.example/a$b)` $x",
    ),
    (
        "a new span splits at a closer seen before it",
        "*a* ![i](https://e.example/b*c)",
        "*a* `![i](https://e.example/b`\\* `c)`",
    ),
    (
        "but not at one seen only after it",
        "![i](https://e.example/b*c) *a*",
        "`![i](https://e.example/b*c)` *a*",
    ),
    (
        "marked may read part of a run into a clean URL",
        "www.x.example/p```)`![i](https://e.example/a)`",
        "www.x.example/p```)` ````![i](https://e.example/a)```` `",
    ),
    (
        "a clean URL ends at a `<` before a line end, which may start an autolink",
        "e.org/p<\ne.org/p<https://a.example>![i](https://e.example/x)",
        "e.org/p<\ne.org/p<https://a.example> `![i](https://e.example/x)`",
    ),
    (
        "a clean URL holding an image goes in code whole",
        "https://x.example/![i](https://e.example/a) end",
        "`https://x.example/![i](https://e.example/a)` end",
    ),
];

fn check(table: &[Case]) {
    for &(case, input, clean) in table {
        let once = disarm(input, false);
        assert_eq!(once.text, clean, "{case}");
        assert_eq!(disarm(clean, false).text, clean, "{case}: twice");
    }
}

#[test]
fn fences_both_parsers_read_as_code() {
    check(FENCES);
}

#[test]
fn lines_end_where_marked_ends_them() {
    check(LINES);
}

#[test]
fn spans_both_parsers_read_as_code() {
    check(SPANS);
}

#[test]
fn labels_and_destinations_end_where_either_parser_ends_them() {
    check(BRACKETS);
}

#[test]
fn what_marked_lets_take_a_backtick_leaves_no_image() {
    check(STEALS);
}

#[test]
fn a_construct_is_looked_for_in_its_first_2048_characters() {
    // From its `[` to its `)`: 2048 characters, found whole.
    let image = |alt: usize| format!("![{}](https://e.example/x)", "a".repeat(alt));
    assert_eq!(
        disarm(&image(2025), false).text,
        format!("`{}`", image(2025))
    );
    // One more, and the `)` is out of reach: the image is read as `![alt]`.
    let alt = "a".repeat(2026);
    let got = disarm(&image(2026), false).text;
    assert_eq!(got, format!("`![{alt}]`(https://e.example/x)"));
    // With the `]` out of reach too, only the `![` goes in code; in an untrusted reply, the URL
    // as well.
    let alt = "a".repeat(2047);
    let got = disarm(&image(2047), false).text;
    assert_eq!(got, format!("`![`{alt}](https://e.example/x)"));
    let got = disarm(&image(2047), true).text;
    assert_eq!(got, format!("`![`{alt}]( `https://e.example/x`)"));
    // A link out of reach keeps only its URL in code.
    let got = disarm(&format!("[{alt}](https://l.example/x)"), true);
    assert_eq!(got.text, format!("[{alt}]( `https://l.example/x`)"));
    assert!(got.links);
}

#[test]
fn an_untrusted_reply_follows_the_same_rules() {
    let text = "- item\n```\nhttps://e.example/a\n```\n\n```\nhttps://e.example/b\n```";
    let got = disarm(text, true);
    assert_eq!(
        got.text,
        "- item\n```\n````https://e.example/a````\n```\n\n```\nhttps://e.example/b\n```"
    );
    assert!(got.links);
}