use super::*;
use pretty_assertions::assert_eq;
use std::collections::HashMap;
use std::collections::HashSet;

fn make_skill(name: &str, path: &str) -> SkillMetadata {
    SkillMetadata {
        name: name.to_string(),
        description: format!("{name} skill"),
        short_description: None,
        interface: None,
        dependencies: None,
        policy: None,
        path_to_skills_md: PathBuf::from(path),
        scope: codex_protocol::protocol::SkillScope::User,
    }
}

fn set<'a>(items: &'a [&'a str]) -> HashSet<&'a str> {
    items.iter().copied().collect()
}

fn assert_mentions(text: &str, expected_names: &[&str], expected_paths: &[&str]) {
    let mentions = extract_tool_mentions(text);
    assert_eq!(mentions.names, set(expected_names));
    assert_eq!(mentions.paths, set(expected_paths));
}

fn collect_mentions(
    inputs: &[UserInput],
    skills: &[SkillMetadata],
    disabled_paths: &HashSet<PathBuf>,
    connector_slug_counts: &HashMap<String, usize>,
) -> Vec<SkillMetadata> {
    collect_explicit_skill_mentions(inputs, skills, disabled_paths, connector_slug_counts)
}

#[test]
fn text_mentions_skill_requires_exact_boundary() {
    assert_eq!(
        true,
        text_mentions_skill("use $notion-research-doc please", "notion-research-doc")
    );
    assert_eq!(
        true,
        text_mentions_skill("($notion-research-doc)", "notion-research-doc")
    );
    assert_eq!(
        true,
        text_mentions_skill("$notion-research-doc.", "notion-research-doc")
    );
    assert_eq!(
        false,
        text_mentions_skill("$notion-research-docs", "notion-research-doc")
    );
    assert_eq!(
        false,
        text_mentions_skill("$notion-research-doc_extra", "notion-research-doc")
    );
}

#[test]
fn text_mentions_skill_handles_end_boundary_and_near_misses() {
    assert_eq!(true, text_mentions_skill("$alpha-skill", "alpha-skill"));
    assert_eq!(false, text_mentions_skill("$alpha-skillx", "alpha-skill"));
    assert_eq!(
        true,
        text_mentions_skill("$alpha-skillx and later $alpha-skill ", "alpha-skill")
    );
}

#[test]
fn text_mentions_skill_handles_many_dollars_without_looping() {
    let prefix = "$".repeat(256);
    let text = format!("{prefix} not-a-mention");
    assert_eq!(false, text_mentions_skill(&text, "alpha-skill"));
}

#[test]
fn extract_tool_mentions_handles_plain_and_linked_mentions() {
    assert_mentions(
        "use $alpha and [$beta](/tmp/beta)",
        &["alpha", "beta"],
        &["/tmp/beta"],
    );
}

#[test]
fn extract_tool_mentions_skips_common_env_vars() {
    assert_mentions("use $PATH and $alpha", &["alpha"], &[]);
    assert_mentions("use [$HOME](/tmp/skill)", &[], &[]);
    assert_mentions("use $XDG_CONFIG_HOME and $beta", &["beta"], &[]);
}

#[test]
fn extract_tool_mentions_requires_link_syntax() {
    assert_mentions("[beta](/tmp/beta)", &[], &[]);
    assert_mentions("[$beta] /tmp/beta", &["beta"], &[]);
    assert_mentions("[$beta]()", &["beta"], &[]);
}

#[test]
fn extract_tool_mentions_trims_linked_paths_and_allows_spacing() {
    assert_mentions("use [$beta]   ( /tmp/beta )", &["beta"], &["/tmp/beta"]);
}

#[test]
fn extract_tool_mentions_stops_at_non_name_chars() {
    assert_mentions(
        "use $alpha.skill and $beta_extra",
        &["alpha", "beta_extra"],
        &[],
    );
}

#[test]
fn extract_tool_mentions_keeps_plugin_skill_namespaces() {
    assert_mentions(
        "use $slack:search and $alpha",
        &["alpha", "slack:search"],
        &[],
    );
}

#[test]
fn collect_explicit_skill_mentions_text_respects_skill_order() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let beta = make_skill("beta-skill", "/tmp/beta");
    let skills = vec![beta.clone(), alpha.clone()];
    let inputs = vec![UserInput::Text {
        text: "first $alpha-skill then $beta-skill".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    // Text scanning should not change the previous selection ordering semantics.
    assert_eq!(selected, vec![beta, alpha]);
}

#[test]
fn collect_explicit_skill_mentions_prioritizes_structured_inputs() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let beta = make_skill("beta-skill", "/tmp/beta");
    let skills = vec![alpha.clone(), beta.clone()];
    let inputs = vec![
        UserInput::Text {
            text: "please run $alpha-skill".to_string(),
            text_elements: Vec::new(),
        },
        UserInput::Skill {
            name: "beta-skill".to_string(),
            path: PathBuf::from("/tmp/beta"),
        },
    ];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, vec![beta, alpha]);
}

#[test]
fn collect_explicit_skill_mentions_skips_invalid_structured_and_blocks_plain_fallback() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let skills = vec![alpha];
    let inputs = vec![
        UserInput::Text {
            text: "please run $alpha-skill".to_string(),
            text_elements: Vec::new(),
        },
        UserInput::Skill {
            name: "alpha-skill".to_string(),
            path: PathBuf::from("/tmp/missing"),
        },
    ];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_skips_disabled_structured_and_blocks_plain_fallback() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let skills = vec![alpha];
    let inputs = vec![
        UserInput::Text {
            text: "please run $alpha-skill".to_string(),
            text_elements: Vec::new(),
        },
        UserInput::Skill {
            name: "alpha-skill".to_string(),
            path: PathBuf::from("/tmp/alpha"),
        },
    ];
    let disabled = HashSet::from([PathBuf::from("/tmp/alpha")]);
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &disabled, &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_dedupes_by_path() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let skills = vec![alpha.clone()];
    let inputs = vec![UserInput::Text {
        text: "use [$alpha-skill](/tmp/alpha) and [$alpha-skill](/tmp/alpha)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, vec![alpha]);
}

#[test]
fn collect_explicit_skill_mentions_skips_ambiguous_name() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let beta = make_skill("demo-skill", "/tmp/beta");
    let skills = vec![alpha, beta];
    let inputs = vec![UserInput::Text {
        text: "use $demo-skill and again $demo-skill".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_prefers_linked_path_over_name() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let beta = make_skill("demo-skill", "/tmp/beta");
    let skills = vec![alpha, beta.clone()];
    let inputs = vec![UserInput::Text {
        text: "use $demo-skill and [$demo-skill](/tmp/beta)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, vec![beta]);
}

#[test]
fn collect_explicit_skill_mentions_skips_plain_name_when_connector_matches() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let skills = vec![alpha];
    let inputs = vec![UserInput::Text {
        text: "use $alpha-skill".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::from([("alpha-skill".to_string(), 1)]);

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_allows_explicit_path_with_connector_conflict() {
    let alpha = make_skill("alpha-skill", "/tmp/alpha");
    let skills = vec![alpha.clone()];
    let inputs = vec![UserInput::Text {
        text: "use [$alpha-skill](/tmp/alpha)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::from([("alpha-skill".to_string(), 1)]);

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, vec![alpha]);
}

#[test]
fn collect_explicit_skill_mentions_skips_when_linked_path_disabled() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let beta = make_skill("demo-skill", "/tmp/beta");
    let skills = vec![alpha, beta];
    let inputs = vec![UserInput::Text {
        text: "use [$demo-skill](/tmp/alpha)".to_string(),
        text_elements: Vec::new(),
    }];
    let disabled = HashSet::from([PathBuf::from("/tmp/alpha")]);
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &disabled, &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_prefers_resource_path() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let beta = make_skill("demo-skill", "/tmp/beta");
    let skills = vec![alpha, beta.clone()];
    let inputs = vec![UserInput::Text {
        text: "use [$demo-skill](/tmp/beta)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, vec![beta]);
}

#[test]
fn collect_explicit_skill_mentions_skips_missing_path_with_no_fallback() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let beta = make_skill("demo-skill", "/tmp/beta");
    let skills = vec![alpha, beta];
    let inputs = vec![UserInput::Text {
        text: "use [$demo-skill](/tmp/missing)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, Vec::new());
}

#[test]
fn collect_explicit_skill_mentions_skips_missing_path_without_fallback() {
    let alpha = make_skill("demo-skill", "/tmp/alpha");
    let skills = vec![alpha];
    let inputs = vec![UserInput::Text {
        text: "use [$demo-skill](/tmp/missing)".to_string(),
        text_elements: Vec::new(),
    }];
    let connector_counts = HashMap::new();

    let selected = collect_mentions(&inputs, &skills, &HashSet::new(), &connector_counts);

    assert_eq!(selected, Vec::new());
}