// Copyright © SixtyFPS GmbH <info@slint-ui.com>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-commercial

use regex::Regex;

pub struct TestCase {
    pub absolute_path: std::path::PathBuf,
    pub relative_path: std::path::PathBuf,
}

impl TestCase {
    /// Return a string which is a valid C++/Rust identifier
    pub fn identifier(&self) -> String {
        self.relative_path
            .with_extension("")
            .to_string_lossy()
            .replace(std::path::MAIN_SEPARATOR, "_")
            .replace('-', "_")
    }
}

/// Returns a list of all the `.slint` files in the subfolders e.g. `tests/cases` .
pub fn collect_test_cases(sub_folders: &str) -> std::io::Result<Vec<TestCase>> {
    let mut results = vec![];

    let case_root_dir: std::path::PathBuf =
        [env!("CARGO_MANIFEST_DIR"), "..", "..", sub_folders].iter().collect();

    println!("cargo:rerun-if-env-changed=SLINT_TEST_FILTER");
    let filter = std::env::var("SLINT_TEST_FILTER").ok();

    for entry in walkdir::WalkDir::new(case_root_dir.clone()).follow_links(true) {
        let entry = entry?;
        let absolute_path = entry.into_path();
        if absolute_path.is_dir() {
            println!("cargo:rerun-if-changed={}", absolute_path.display());
            continue;
        }
        let relative_path =
            std::path::PathBuf::from(absolute_path.strip_prefix(&case_root_dir).unwrap());
        if let Some(filter) = &filter {
            if !relative_path.to_str().unwrap().contains(filter) {
                continue;
            }
        }
        if let Some(ext) = absolute_path.extension() {
            if ext == "60" || ext == "slint" {
                results.push(TestCase { absolute_path, relative_path });
            }
        }
    }
    Ok(results)
}

/// A test functions looks something like
/// ````text
/// /*
///   ```cpp
///   TestCase instance;
///   assert(instance.x.get() == 0);
///   ```
/// */
/// ````
pub struct TestFunction<'a> {
    /// In the example above: `cpp`
    pub language_id: &'a str,
    /// The content of the test function
    pub source: &'a str,
}

/// Extract the test functions from
pub fn extract_test_functions(source: &str) -> impl Iterator<Item = TestFunction<'_>> {
    lazy_static::lazy_static! {
        static ref RX: Regex = Regex::new(r"(?sU)\r?\n```([a-z]+)\r?\n(.+)\r?\n```\r?\n").unwrap();
    }
    RX.captures_iter(source).map(|mat| TestFunction {
        language_id: mat.get(1).unwrap().as_str(),
        source: mat.get(2).unwrap().as_str(),
    })
}

#[test]
fn test_extract_test_functions() {
    let source = r"
/*
```cpp
auto xx = 0;
auto yy = 0;
```

```rust
let xx = 0;
let yy = 0;
```
*/
";
    let mut r = extract_test_functions(source);

    let r1 = r.next().unwrap();
    assert_eq!(r1.language_id, "cpp");
    assert_eq!(r1.source, "auto xx = 0;\nauto yy = 0;");

    let r2 = r.next().unwrap();
    assert_eq!(r2.language_id, "rust");
    assert_eq!(r2.source, "let xx = 0;\nlet yy = 0;");
}

#[test]
fn test_extract_test_functions_win() {
    let source = "/*\r\n```cpp\r\nfoo\r\nbar\r\n```\r\n*/\r\n";
    let mut r = extract_test_functions(source);
    let r1 = r.next().unwrap();
    assert_eq!(r1.language_id, "cpp");
    assert_eq!(r1.source, "foo\r\nbar");
}

/// Extract extra include paths from a comment in the source if present.
pub fn extract_include_paths(source: &str) -> impl Iterator<Item = &'_ str> {
    lazy_static::lazy_static! {
        static ref RX: Regex = Regex::new(r"//include_path:\s*(.+)\s*\n").unwrap();
    }
    RX.captures_iter(source).map(|mat| mat.get(1).unwrap().as_str().trim())
}

#[test]
fn test_extract_include_paths() {
    assert!(extract_include_paths("something").next().is_none());

    let source = r"
    //include_path: ../first
    //include_path: ../second
    Blah {}
";

    let r = extract_include_paths(source).collect::<Vec<_>>();
    assert_eq!(r, ["../first", "../second"]);

    // Windows \r\n
    let source = "//include_path: ../first\r\n//include_path: ../second\r\nBlah {}\r\n";
    let r = extract_include_paths(source).collect::<Vec<_>>();
    assert_eq!(r, ["../first", "../second"]);
}