use expect_test::{expect, Expect};
use mbe::ast_to_token_tree;
use syntax::{ast, AstNode};

use crate::{CfgAtom, CfgExpr, CfgOptions, DnfExpr};

fn assert_parse_result(input: &str, expected: CfgExpr) {
    let (tt, _) = {
        let source_file = ast::SourceFile::parse(input).ok().unwrap();
        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
        ast_to_token_tree(&tt)
    };
    let cfg = CfgExpr::parse(&tt);
    assert_eq!(cfg, expected);
}

fn check_dnf(input: &str, expect: Expect) {
    let (tt, _) = {
        let source_file = ast::SourceFile::parse(input).ok().unwrap();
        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
        ast_to_token_tree(&tt)
    };
    let cfg = CfgExpr::parse(&tt);
    let actual = format!("#![cfg({})]", DnfExpr::new(cfg));
    expect.assert_eq(&actual);
}

fn check_why_inactive(input: &str, opts: &CfgOptions, expect: Expect) {
    let (tt, _) = {
        let source_file = ast::SourceFile::parse(input).ok().unwrap();
        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
        ast_to_token_tree(&tt)
    };
    let cfg = CfgExpr::parse(&tt);
    let dnf = DnfExpr::new(cfg);
    let why_inactive = dnf.why_inactive(opts).unwrap().to_string();
    expect.assert_eq(&why_inactive);
}

#[track_caller]
fn check_enable_hints(input: &str, opts: &CfgOptions, expected_hints: &[&str]) {
    let (tt, _) = {
        let source_file = ast::SourceFile::parse(input).ok().unwrap();
        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
        ast_to_token_tree(&tt)
    };
    let cfg = CfgExpr::parse(&tt);
    let dnf = DnfExpr::new(cfg);
    let hints = dnf.compute_enable_hints(opts).map(|diff| diff.to_string()).collect::<Vec<_>>();
    assert_eq!(hints, expected_hints);
}

#[test]
fn test_cfg_expr_parser() {
    assert_parse_result("#![cfg(foo)]", CfgAtom::Flag("foo".into()).into());
    assert_parse_result("#![cfg(foo,)]", CfgAtom::Flag("foo".into()).into());
    assert_parse_result(
        "#![cfg(not(foo))]",
        CfgExpr::Not(Box::new(CfgAtom::Flag("foo".into()).into())),
    );
    assert_parse_result("#![cfg(foo(bar))]", CfgExpr::Invalid);

    // Only take the first
    assert_parse_result(r#"#![cfg(foo, bar = "baz")]"#, CfgAtom::Flag("foo".into()).into());

    assert_parse_result(
        r#"#![cfg(all(foo, bar = "baz"))]"#,
        CfgExpr::All(vec![
            CfgAtom::Flag("foo".into()).into(),
            CfgAtom::KeyValue { key: "bar".into(), value: "baz".into() }.into(),
        ]),
    );

    assert_parse_result(
        r#"#![cfg(any(not(), all(), , bar = "baz",))]"#,
        CfgExpr::Any(vec![
            CfgExpr::Not(Box::new(CfgExpr::Invalid)),
            CfgExpr::All(vec![]),
            CfgExpr::Invalid,
            CfgAtom::KeyValue { key: "bar".into(), value: "baz".into() }.into(),
        ]),
    );
}

#[test]
fn smoke() {
    check_dnf("#![cfg(test)]", expect![[r#"#![cfg(test)]"#]]);
    check_dnf("#![cfg(not(test))]", expect![[r#"#![cfg(not(test))]"#]]);
    check_dnf("#![cfg(not(not(test)))]", expect![[r#"#![cfg(test)]"#]]);

    check_dnf("#![cfg(all(a, b))]", expect![[r#"#![cfg(all(a, b))]"#]]);
    check_dnf("#![cfg(any(a, b))]", expect![[r#"#![cfg(any(a, b))]"#]]);

    check_dnf("#![cfg(not(a))]", expect![[r#"#![cfg(not(a))]"#]]);
}

#[test]
fn distribute() {
    check_dnf("#![cfg(all(any(a, b), c))]", expect![[r#"#![cfg(any(all(a, c), all(b, c)))]"#]]);
    check_dnf("#![cfg(all(c, any(a, b)))]", expect![[r#"#![cfg(any(all(c, a), all(c, b)))]"#]]);
    check_dnf(
        "#![cfg(all(any(a, b), any(c, d)))]",
        expect![[r#"#![cfg(any(all(a, c), all(a, d), all(b, c), all(b, d)))]"#]],
    );

    check_dnf(
        "#![cfg(all(any(a, b, c), any(d, e, f), g))]",
        expect![[
            r#"#![cfg(any(all(a, d, g), all(a, e, g), all(a, f, g), all(b, d, g), all(b, e, g), all(b, f, g), all(c, d, g), all(c, e, g), all(c, f, g)))]"#
        ]],
    );
}

#[test]
fn demorgan() {
    check_dnf("#![cfg(not(all(a, b)))]", expect![[r#"#![cfg(any(not(a), not(b)))]"#]]);
    check_dnf("#![cfg(not(any(a, b)))]", expect![[r#"#![cfg(all(not(a), not(b)))]"#]]);

    check_dnf("#![cfg(not(all(not(a), b)))]", expect![[r#"#![cfg(any(a, not(b)))]"#]]);
    check_dnf("#![cfg(not(any(a, not(b))))]", expect![[r#"#![cfg(all(not(a), b))]"#]]);
}

#[test]
fn nested() {
    check_dnf("#![cfg(all(any(a), not(all(any(b)))))]", expect![[r#"#![cfg(all(a, not(b)))]"#]]);

    check_dnf("#![cfg(any(any(a, b)))]", expect![[r#"#![cfg(any(a, b))]"#]]);
    check_dnf("#![cfg(not(any(any(a, b))))]", expect![[r#"#![cfg(all(not(a), not(b)))]"#]]);
    check_dnf("#![cfg(all(all(a, b)))]", expect![[r#"#![cfg(all(a, b))]"#]]);
    check_dnf("#![cfg(not(all(all(a, b))))]", expect![[r#"#![cfg(any(not(a), not(b)))]"#]]);
}

#[test]
fn hints() {
    let mut opts = CfgOptions::default();

    check_enable_hints("#![cfg(test)]", &opts, &["enable test"]);
    check_enable_hints("#![cfg(not(test))]", &opts, &[]);

    check_enable_hints("#![cfg(any(a, b))]", &opts, &["enable a", "enable b"]);
    check_enable_hints("#![cfg(any(b, a))]", &opts, &["enable b", "enable a"]);

    check_enable_hints("#![cfg(all(a, b))]", &opts, &["enable a and b"]);

    opts.insert_atom("test".into());

    check_enable_hints("#![cfg(test)]", &opts, &[]);
    check_enable_hints("#![cfg(not(test))]", &opts, &["disable test"]);
}

/// Tests that we don't suggest hints for cfgs that express an inconsistent formula.
#[test]
fn hints_impossible() {
    let mut opts = CfgOptions::default();

    check_enable_hints("#![cfg(all(test, not(test)))]", &opts, &[]);

    opts.insert_atom("test".into());

    check_enable_hints("#![cfg(all(test, not(test)))]", &opts, &[]);
}

#[test]
fn why_inactive() {
    let mut opts = CfgOptions::default();
    opts.insert_atom("test".into());
    opts.insert_atom("test2".into());

    check_why_inactive("#![cfg(a)]", &opts, expect![["a is disabled"]]);
    check_why_inactive("#![cfg(not(test))]", &opts, expect![["test is enabled"]]);

    check_why_inactive(
        "#![cfg(all(not(test), not(test2)))]",
        &opts,
        expect![["test and test2 are enabled"]],
    );
    check_why_inactive("#![cfg(all(a, b))]", &opts, expect![["a and b are disabled"]]);
    check_why_inactive(
        "#![cfg(all(not(test), a))]",
        &opts,
        expect![["test is enabled and a is disabled"]],
    );
    check_why_inactive(
        "#![cfg(all(not(test), test2, a))]",
        &opts,
        expect![["test is enabled and a is disabled"]],
    );
    check_why_inactive(
        "#![cfg(all(not(test), not(test2), a))]",
        &opts,
        expect![["test and test2 are enabled and a is disabled"]],
    );
}