use std::collections::{HashMap, HashSet};
use std::fs;
use std::process::Command;

#[test]
fn a1_all_members_build() {
    let output = Command::new("cargo")
        .args(&["build", "--workspace"])
        .output()
        .expect("Failed to run cargo build");

    assert!(
        output.status.success(),
        "cargo build --workspace failed:\nstdout: {}\nstderr: {}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr)
    );
}

#[test]
fn a2_mem_core_has_no_sibling_deps() {
    let cargo_toml_path = "crates/mem-core/Cargo.toml";
    let content = fs::read_to_string(cargo_toml_path)
        .expect("Failed to read mem-core Cargo.toml");

    let table: toml::Table = toml::from_str(&content)
        .expect("Failed to parse Cargo.toml");

    // Check dependencies section
    if let Some(deps) = table.get("dependencies") {
        if let Some(deps_table) = deps.as_table() {
            for key in deps_table.keys() {
                assert!(
                    !key.starts_with("mem-"),
                    "mem-core should not depend on {}, found dependency in Cargo.toml",
                    key
                );
            }
        }
    }

    // Check dev-dependencies section
    if let Some(dev_deps) = table.get("dev-dependencies") {
        if let Some(dev_deps_table) = dev_deps.as_table() {
            for key in dev_deps_table.keys() {
                assert!(
                    !key.starts_with("mem-"),
                    "mem-core should not have dev-dependency on {}",
                    key
                );
            }
        }
    }
}

#[test]
fn a3_dependency_direction() {
    // Define the allowed edges (dependency direction)
    let allowed_edges: HashSet<(String, String)> = vec![
        ("mem-cli".to_string(), "mem-ingest".to_string()),
        ("mem-cli".to_string(), "mem-store".to_string()),
        ("mem-cli".to_string(), "mem-llm".to_string()),
        ("mem-cli".to_string(), "mem-chunk".to_string()),
        ("mem-cli".to_string(), "mem-core".to_string()),
        ("mem-store".to_string(), "mem-core".to_string()),
        ("mem-ingest".to_string(), "mem-chunk".to_string()),
        ("mem-ingest".to_string(), "mem-core".to_string()),
        ("mem-chunk".to_string(), "mem-core".to_string()),
        ("mem-llm".to_string(), "mem-core".to_string()),
    ]
    .into_iter()
    .collect();

    let crates = vec!["mem-core", "mem-chunk", "mem-llm", "mem-ingest", "mem-store", "mem-cli"];
    let mut edges: HashSet<(String, String)> = HashSet::new();

    // Parse each crate's Cargo.toml
    for crate_name in &crates {
        let cargo_toml_path = format!("crates/{}/Cargo.toml", crate_name);
        let content = fs::read_to_string(&cargo_toml_path)
            .unwrap_or_else(|_| panic!("Failed to read {}", cargo_toml_path));

        let table: toml::Table = toml::from_str(&content)
            .unwrap_or_else(|_| panic!("Failed to parse {}", cargo_toml_path));

        // Check dependencies
        if let Some(deps) = table.get("dependencies") {
            if let Some(deps_table) = deps.as_table() {
                for key in deps_table.keys() {
                    if key.starts_with("mem-") {
                        edges.insert((crate_name.to_string(), key.clone()));
                    }
                }
            }
        }
    }

    // Check that all edges are allowed
    for (from, to) in &edges {
        assert!(
            allowed_edges.contains(&(from.clone(), to.clone())),
            "Invalid edge: {} -> {} not in allowed dependency graph",
            from,
            to
        );
    }

    // Check for cycles using DFS
    let mut graph: HashMap<String, Vec<String>> = HashMap::new();
    for crate_name in &crates {
        graph.insert(crate_name.to_string(), Vec::new());
    }
    for (from, to) in &edges {
        graph.entry(from.clone()).or_insert_with(Vec::new).push(to.clone());
    }

    // DFS to detect cycles
    fn has_cycle(
        node: &str,
        graph: &HashMap<String, Vec<String>>,
        visited: &mut HashSet<String>,
        rec_stack: &mut HashSet<String>,
    ) -> bool {
        visited.insert(node.to_string());
        rec_stack.insert(node.to_string());

        if let Some(neighbors) = graph.get(node) {
            for neighbor in neighbors {
                if !visited.contains(neighbor) {
                    if has_cycle(neighbor, graph, visited, rec_stack) {
                        return true;
                    }
                } else if rec_stack.contains(neighbor) {
                    return true;
                }
            }
        }

        rec_stack.remove(node);
        false
    }

    let mut visited = HashSet::new();
    let mut rec_stack = HashSet::new();
    for crate_name in &crates {
        if !visited.contains(*crate_name) {
            assert!(
                !has_cycle(crate_name, &graph, &mut visited, &mut rec_stack),
                "Cycle detected in dependency graph"
            );
        }
    }
}

#[test]
fn a4_log_and_tasks_are_tracked() {
    let gitignore_path = ".gitignore";
    let content = fs::read_to_string(gitignore_path)
        .expect("Failed to read .gitignore");

    // Check that log/ is NOT ignored
    let log_lines: Vec<&str> = content.lines()
        .filter(|line| line.trim() == "log/")
        .collect();
    
    for line in log_lines {
        assert!(
            line.starts_with("#"),
            ".gitignore should not ignore log/ (the authoritative JSONL event log)"
        );
    }

    // Check that tasks/ is NOT ignored
    let has_tasks_ignored = content.lines()
        .filter(|line| {
            let trimmed = line.trim();
            (trimmed == "tasks/" || trimmed == "memory-tasks/") && !line.starts_with("#")
        })
        .count() > 0;

    assert!(
        !has_tasks_ignored,
        ".gitignore should not ignore tasks/ (the task board)"
    );
}