zoi-core 1.25.4

use std::collections::{HashMap, HashSet};
use std::fs;
use std::io::{self, Write};
use std::path::{Path, PathBuf};

use anyhow::{Result, anyhow};
use colored::Colorize;
use serde_yaml::Value;

use crate::sysroot::apply_sysroot;
use crate::types::{Config, Registry, RepoConfig};
use crate::utils::{get_db_root, get_user_home};

/// Returns the default registry URL for Zoi.
///
/// This is typically hardcoded or provided via an environment variable during
/// the build.
pub fn get_default_registry() -> String {
    option_env!("ZOI_DEFAULT_REGISTRY")
        .unwrap_or("community")
        .to_string()
}

/// Returns the built-in PGP authorities for the default registry.
pub fn get_builtin_authorities() -> Vec<String> {
    let auth_str = option_env!("ZOI_BUILTIN_AUTHORITIES").unwrap_or_default();
    if auth_str.is_empty() {
        Vec::new()
    } else {
        auth_str.split(',').map(ToString::to_string).collect()
    }
}

/// Returns the path to the system-wide configuration file.
fn get_system_config_path() -> PathBuf {
    if cfg!(target_os = "windows") {
        apply_sysroot(PathBuf::from("C:\\ProgramData\\zoi\\config.yaml"))
    } else {
        apply_sysroot(PathBuf::from("/etc/zoi/config.yaml"))
    }
}

/// Returns the path to the user-specific configuration file.
fn get_user_config_path() -> Result<PathBuf> {
    let home_dir = get_user_home()
        .ok_or_else(|| anyhow!("Could not find home directory."))?;
    Ok(apply_sysroot(home_dir.join(".zoi"))
        .join("pkgs")
        .join("config.yaml"))
}

/// Returns the path to the project-local configuration file.
fn get_project_config_path() -> Result<PathBuf> {
    let current_dir = std::env::current_dir()?;
    Ok(apply_sysroot(current_dir.join(".zoi"))
        .join("pkgs")
        .join("config.yaml"))
}

/// Returns the path to the directory where git repositories are cloned.
fn get_git_root() -> Result<PathBuf> {
    let home_dir = get_user_home()
        .ok_or_else(|| anyhow!("Could not find home directory."))?;
    Ok(apply_sysroot(home_dir.join(".zoi"))
        .join("pkgs")
        .join("git"))
}

/// Returns the path to the remote policy cache file.
fn get_remote_policy_cache_path() -> PathBuf {
    if cfg!(target_os = "windows") {
        apply_sysroot(PathBuf::from("C:\\ProgramData\\zoi\\policy.cache.yaml"))
    } else {
        apply_sysroot(PathBuf::from("/etc/zoi/policy.cache.yaml"))
    }
}

/// Reads a YAML value from the specified path.
fn read_yaml_value(path: &Path) -> Result<Value> {
    if !path.exists() {
        return Ok(Value::Null);
    }
    let content = fs::read_to_string(path)?;
    serde_yaml::from_str(&content).map_err(Into::into)
}

/// Reads a Zoi configuration from the specified path.
fn read_config_from_path(path: &Path) -> Result<Config> {
    if !path.exists() {
        return Ok(Config::default());
    }
    let content = fs::read_to_string(path)?;
    serde_yaml::from_str(&content).map_err(Into::into)
}

/// Loads and merges configuration from system, user, and project-local paths.
///
/// Zoi uses a hierarchical configuration model with the following precedence:
/// - System: (`/etc/zoi/config.yaml`) - Defines global machine policy.
/// - User: (`~/.zoi/pkgs/config.yaml`) - Defines user preferences.
/// - Project: (`./.zoi/pkgs/config.yaml`) - Local overrides for a specific
///   project.
///
/// Policy Enforcement: If a field is marked as `unoverridable` in the
/// system-level policy, Zoi will ignore any overrides found in user or project
/// configs.
///
/// # Errors
///
/// Returns an error if any of the configuration files cannot be read or parsed.
pub fn read_config() -> Result<Config> {
    let system_val = read_yaml_value(&get_system_config_path())?;
    let user_val = read_yaml_value(&get_user_config_path()?)?;
    let project_val = read_yaml_value(&get_project_config_path()?)?;

    let mut system_cfg: Config =
        serde_yaml::from_value(system_val.clone()).unwrap_or_default();
    let user_cfg: Config =
        serde_yaml::from_value(user_val.clone()).unwrap_or_default();
    let project_cfg: Config =
        serde_yaml::from_value(project_val.clone()).unwrap_or_default();

    let cache_path = get_remote_policy_cache_path();
    if cache_path.exists()
        && let Ok(cache_content) = fs::read_to_string(&cache_path)
        && let Ok(remote_policy) =
            serde_yaml::from_str::<crate::types::Policy>(&cache_content)
    {
        merge_policies(&mut system_cfg.policy, &remote_policy);
    }

    let system_policy = system_cfg.policy.clone();
    let mut merged_cfg = Config {
        policy: system_policy.clone(),
        ..Default::default()
    };

    merged_cfg.repos = system_cfg.repos;
    if !system_policy.repos_unoverridable {
        merged_cfg.repos.extend(user_cfg.repos);
        merged_cfg.repos.extend(project_cfg.repos);
    }
    merged_cfg.repos.sort();
    merged_cfg.repos.dedup();

    merged_cfg.added_registries = system_cfg.added_registries;
    if !system_policy.added_registries_unoverridable {
        merged_cfg
            .added_registries
            .extend(user_cfg.added_registries);
        merged_cfg
            .added_registries
            .extend(project_cfg.added_registries);
    }
    let mut seen_registries = HashSet::new();
    merged_cfg
        .added_registries
        .retain(|r| seen_registries.insert(r.url.clone()));

    merged_cfg.git_repos = system_cfg.git_repos;
    if !system_policy.git_repos_unoverridable {
        merged_cfg.git_repos.extend(user_cfg.git_repos);
        merged_cfg.git_repos.extend(project_cfg.git_repos);
    }
    merged_cfg.git_repos.sort();
    merged_cfg.git_repos.dedup();

    merged_cfg.package_managers = project_cfg
        .package_managers
        .or(user_cfg.package_managers)
        .or(system_cfg.package_managers);
    merged_cfg.native_package_manager = project_cfg
        .native_package_manager
        .or(user_cfg.native_package_manager)
        .or(system_cfg.native_package_manager);
    merged_cfg.registry = project_cfg
        .registry
        .or(user_cfg.registry)
        .or(system_cfg.registry);

    merged_cfg.remote_policy = system_cfg.remote_policy;

    if project_val.get("telemetry_enabled").is_some()
        && !system_policy.telemetry_enabled_unoverridable
    {
        merged_cfg.telemetry_enabled = project_cfg.telemetry_enabled;
    } else if user_val.get("telemetry_enabled").is_some()
        && !system_policy.telemetry_enabled_unoverridable
    {
        merged_cfg.telemetry_enabled = user_cfg.telemetry_enabled;
    } else {
        merged_cfg.telemetry_enabled = system_cfg.telemetry_enabled;
    }

    if project_val.get("audit_log_enabled").is_some()
        && !system_policy.audit_log_enabled_unoverridable
    {
        merged_cfg.audit_log_enabled = project_cfg.audit_log_enabled;
    } else if user_val.get("audit_log_enabled").is_some()
        && !system_policy.audit_log_enabled_unoverridable
    {
        merged_cfg.audit_log_enabled = user_cfg.audit_log_enabled;
    } else {
        merged_cfg.audit_log_enabled = system_cfg.audit_log_enabled;
    }

    if project_val.get("rollback_enabled").is_some()
        && !system_policy.rollback_enabled_unoverridable
    {
        merged_cfg.rollback_enabled = project_cfg.rollback_enabled;
    } else if user_val.get("rollback_enabled").is_some()
        && !system_policy.rollback_enabled_unoverridable
    {
        merged_cfg.rollback_enabled = user_cfg.rollback_enabled;
    } else {
        merged_cfg.rollback_enabled = system_cfg.rollback_enabled;
    }

    if project_val.get("default_registry").is_some()
        && !system_policy.default_registry_unoverridable
    {
        merged_cfg.default_registry = project_cfg.default_registry;
    } else if user_val.get("default_registry").is_some()
        && !system_policy.default_registry_unoverridable
    {
        merged_cfg.default_registry = user_cfg.default_registry;
    } else {
        merged_cfg.default_registry = system_cfg.default_registry;
    }

    if project_val.get("jobs").is_some() && !system_policy.jobs_unoverridable {
        merged_cfg.jobs = project_cfg.jobs;
    } else if user_val.get("jobs").is_some()
        && !system_policy.jobs_unoverridable
    {
        merged_cfg.jobs = user_cfg.jobs;
    } else {
        merged_cfg.jobs = system_cfg.jobs;
    }

    if project_val.get("protect_db").is_some()
        && !system_policy.protect_db_unoverridable
    {
        merged_cfg.protect_db = project_cfg.protect_db;
    } else if user_val.get("protect_db").is_some()
        && !system_policy.protect_db_unoverridable
    {
        merged_cfg.protect_db = user_cfg.protect_db;
    } else {
        merged_cfg.protect_db = system_cfg.protect_db;
    }

    if project_val.get("max_resolution_depth").is_some()
        && !system_policy.max_resolution_depth_unoverridable
    {
        merged_cfg.max_resolution_depth = project_cfg.max_resolution_depth;
    } else if user_val.get("max_resolution_depth").is_some()
        && !system_policy.max_resolution_depth_unoverridable
    {
        merged_cfg.max_resolution_depth = user_cfg.max_resolution_depth;
    } else {
        merged_cfg.max_resolution_depth = system_cfg.max_resolution_depth;
    }

    if project_val.get("offline_mode").is_some()
        && !system_policy.offline_mode_unoverridable
    {
        merged_cfg.offline_mode = project_cfg.offline_mode;
    } else if user_val.get("offline_mode").is_some()
        && !system_policy.offline_mode_unoverridable
    {
        merged_cfg.offline_mode = user_cfg.offline_mode;
    } else {
        merged_cfg.offline_mode = system_cfg.offline_mode;
    }

    if project_val
        .get("policy")
        .and_then(|p| p.get("advisory_enforcement_unoverridable"))
        .is_some()
        && !system_policy.advisory_enforcement_unoverridable
    {
        merged_cfg.policy.advisory_enforcement_unoverridable =
            project_cfg.policy.advisory_enforcement_unoverridable;
    } else if user_val
        .get("policy")
        .and_then(|p| p.get("advisory_enforcement_unoverridable"))
        .is_some()
        && !system_policy.advisory_enforcement_unoverridable
    {
        merged_cfg.policy.advisory_enforcement_unoverridable =
            user_cfg.policy.advisory_enforcement_unoverridable;
    } else {
        merged_cfg.policy.advisory_enforcement_unoverridable =
            system_cfg.policy.advisory_enforcement_unoverridable;
    }

    merged_cfg.versions = system_cfg.versions;
    merged_cfg.versions.extend(user_cfg.versions);
    merged_cfg.versions.extend(project_cfg.versions);

    merged_cfg.pkg_dirs = system_cfg.pkg_dirs;
    if !system_policy.pkg_dirs_unoverridable {
        merged_cfg.pkg_dirs.extend(user_cfg.pkg_dirs);
        merged_cfg.pkg_dirs.extend(project_cfg.pkg_dirs);
    }
    merged_cfg.pkg_dirs.sort();
    merged_cfg.pkg_dirs.dedup();

    merged_cfg.cache_mirrors = system_cfg.cache_mirrors;
    if !system_policy.cache_mirrors_unoverridable {
        merged_cfg.cache_mirrors.extend(user_cfg.cache_mirrors);
        merged_cfg.cache_mirrors.extend(project_cfg.cache_mirrors);
    }
    merged_cfg.cache_mirrors.sort();
    merged_cfg.cache_mirrors.dedup();

    if !system_policy.allow_deny_lists_unoverridable {
        if project_cfg.policy.allowed_licenses.is_some() {
            merged_cfg.policy.allowed_licenses =
                project_cfg.policy.allowed_licenses;
        } else if user_cfg.policy.allowed_licenses.is_some() {
            merged_cfg.policy.allowed_licenses =
                user_cfg.policy.allowed_licenses;
        }
        if project_cfg.policy.denied_licenses.is_some() {
            merged_cfg.policy.denied_licenses =
                project_cfg.policy.denied_licenses;
        } else if user_cfg.policy.denied_licenses.is_some() {
            merged_cfg.policy.denied_licenses = user_cfg.policy.denied_licenses;
        }
        if project_cfg.policy.allowed_packages.is_some() {
            merged_cfg.policy.allowed_packages =
                project_cfg.policy.allowed_packages;
        } else if user_cfg.policy.allowed_packages.is_some() {
            merged_cfg.policy.allowed_packages =
                user_cfg.policy.allowed_packages;
        }
        if project_cfg.policy.denied_packages.is_some() {
            merged_cfg.policy.denied_packages =
                project_cfg.policy.denied_packages;
        } else if user_cfg.policy.denied_packages.is_some() {
            merged_cfg.policy.denied_packages = user_cfg.policy.denied_packages;
        }
        if project_cfg.policy.allowed_repos.is_some() {
            merged_cfg.policy.allowed_repos = project_cfg.policy.allowed_repos;
        } else if user_cfg.policy.allowed_repos.is_some() {
            merged_cfg.policy.allowed_repos = user_cfg.policy.allowed_repos;
        }
        if project_cfg.policy.denied_repos.is_some() {
            merged_cfg.policy.denied_repos = project_cfg.policy.denied_repos;
        } else if user_cfg.policy.denied_repos.is_some() {
            merged_cfg.policy.denied_repos = user_cfg.policy.denied_repos;
        }
    }

    if !system_policy.signature_enforcement_unoverridable {
        if project_cfg.policy.signature_enforcement.is_some() {
            merged_cfg.policy.signature_enforcement =
                project_cfg.policy.signature_enforcement;
        } else if user_cfg.policy.signature_enforcement.is_some() {
            merged_cfg.policy.signature_enforcement =
                user_cfg.policy.signature_enforcement;
        }
    }

    if let Some(url) = merged_cfg.registry.take()
        && merged_cfg.default_registry.is_none()
    {
        merged_cfg.default_registry = Some(Registry {
            handle: String::new(),
            url,
            advisory_prefix: None,
            authorities: None
        });
    }

    if merged_cfg.default_registry.is_none() {
        merged_cfg.default_registry = Some(Registry {
            handle: "zoidberg".to_string(),
            url: get_default_registry(),
            advisory_prefix: Some("ZSA".to_string()),
            authorities: Some(get_builtin_authorities())
        });
    } else if let Some(ref mut reg) = merged_cfg.default_registry
        && reg.url == get_default_registry()
        && reg.authorities.as_ref().is_none_or(Vec::is_empty)
    {
        let builtin = get_builtin_authorities();
        if !builtin.is_empty() {
            reg.authorities = Some(builtin);
        }
    }

    if merged_cfg.repos.is_empty()
        && let Some(reg) = &merged_cfg.default_registry
        && !reg.handle.is_empty()
    {
        let db_root = get_db_root()?;
        let repo_path = db_root.join(&reg.handle);
        if repo_path.join("repo.yaml").exists()
            && let Ok(repo_config) = read_repo_config(&repo_path)
        {
            merged_cfg.repos = repo_config
                .repos
                .into_iter()
                .filter(|r| r.active)
                .map(|r| r.name)
                .collect();
        }
    }

    if project_val.get("system_generations_limit").is_some()
        && !system_policy.system_generations_limit_unoverridable
    {
        merged_cfg.system_generations_limit =
            project_cfg.system_generations_limit;
    } else if user_val.get("system_generations_limit").is_some()
        && !system_policy.system_generations_limit_unoverridable
    {
        merged_cfg.system_generations_limit = user_cfg.system_generations_limit;
    } else {
        merged_cfg.system_generations_limit =
            system_cfg.system_generations_limit;
    }

    Ok(merged_cfg)
}

/// Writes the user-specific configuration to disk.
///
/// # Errors
///
/// Returns an error if the configuration directory cannot be created or the
/// file cannot be written.
pub fn write_user_config(config: &Config) -> Result<()> {
    let config_path = get_user_config_path()?;
    let parent_dir = config_path
        .parent()
        .ok_or_else(|| anyhow!("Invalid config path"))?;
    fs::create_dir_all(parent_dir)?;
    let content = serde_yaml::to_string(config)?;
    fs::write(config_path, content)?;
    Ok(())
}

/// Verifies a remote file against a set of trusted PGP keys.
///
/// # Errors
///
/// Returns an error if:
/// - The file or its signature cannot be fetched.
/// - The signature is invalid or not signed by a trusted key.
pub fn verify_remote_file(
    url: &str,
    trusted_keys: &[String]
) -> Result<Vec<u8>> {
    let client = crate::utils::get_http_client()?;

    let response = client.get(url).send()?;
    if !response.status().is_success() {
        return Err(anyhow!(
            "Failed to fetch remote file '{url}': {}",
            response.status()
        ));
    }
    let data = response.bytes()?;

    let sig_url = format!("{url}.sig");
    let sig_response = client.get(&sig_url).send()?;
    if !sig_response.status().is_success() {
        return Err(anyhow!(
            "Failed to fetch signature for '{url}': {}",
            sig_response.status()
        ));
    }
    let sig = sig_response.bytes()?;

    let trusted_certs =
        crate::pgp::get_certs_by_name_or_fingerprint(trusted_keys)?;

    let temp_dir = tempfile::Builder::new().prefix("zoi-verify-").tempdir()?;
    let data_path = temp_dir.path().join("data");
    let sig_path = temp_dir.path().join("sig");

    fs::write(&data_path, &data)?;
    fs::write(&sig_path, &sig)?;

    crate::pgp::verify_detached_signature_multi_key(
        &data_path,
        &sig_path,
        trusted_certs
    )?;

    Ok(data.to_vec())
}

/// Adds a repository to the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the repository already exists or if the configuration
/// cannot be written.
pub fn add_repo(repo_name: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    let lower_repo_name = repo_name.to_lowercase();
    if config.repos.contains(&lower_repo_name) {
        return Err(anyhow!(
            "Repository '{repo_name}' already exists in user config."
        ));
    }
    config.repos.push(lower_repo_name);
    write_user_config(&config)
}

/// Removes a repository from the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the repository is not found or if the configuration
/// cannot be written.
pub fn remove_repo(repo_name: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    let lower_repo_name = repo_name.to_lowercase();
    if let Some(pos) = config.repos.iter().position(|r| r == &lower_repo_name) {
        config.repos.remove(pos);
        write_user_config(&config)
    } else {
        Err(anyhow!(
            "Repository '{repo_name}' not found in user config."
        ))
    }
}

/// Prompts the user to interactively add a repository.
///
/// # Errors
///
/// Returns an error if:
/// - Input/output operations fail.
/// - The user provides invalid input.
/// - The repository cannot be added.
pub fn interactive_add_repo() -> Result<()> {
    let config = read_config()?;
    let all_repos = get_all_repos()?;

    let available_repos: Vec<_> = all_repos
        .into_iter()
        .filter(|r| !config.repos.contains(&r.to_lowercase()))
        .collect();

    if available_repos.is_empty() {
        println!("{}", "No new repositories available to add.".yellow());
        return Ok(());
    }

    println!("{}", "Available repositories to add:".green());
    for (i, repo) in available_repos.iter().enumerate() {
        println!("[{}] {}", i + 1, repo);
    }

    print!(
        "\n{}",
        "Select a repository to add (or 'q' to quit): ".yellow()
    );
    io::stdout().flush()?;

    let mut input = String::new();
    io::stdin().read_line(&mut input)?;
    let input = input.trim();

    if input == "q" {
        println!("Aborted.");
        return Ok(());
    }

    let choice: usize = match input.parse() {
        Ok(num) => num,
        Err(_) => return Err(anyhow!("Invalid input."))
    };

    if choice > 0 && choice <= available_repos.len() {
        let repo_to_add = available_repos
            .get(choice - 1)
            .ok_or_else(|| anyhow!("Invalid choice"))?;
        add_repo(repo_to_add)?;
        println!("Repository '{}' added successfully.", repo_to_add.green());
    } else {
        return Err(anyhow!("Invalid selection."));
    }

    Ok(())
}

/// Returns a list of all available repositories from the default registry.
///
/// # Errors
///
/// Returns an error if the repository configuration cannot be read.
pub fn get_all_repos() -> Result<Vec<String>> {
    let db_root = get_db_root()?;
    let config = read_config()?;

    if let Some(default_reg) = config.default_registry
        && !default_reg.handle.is_empty()
    {
        let default_reg_path = db_root.join(default_reg.handle);
        if default_reg_path.join("repo.yaml").exists() {
            let repo_config = read_repo_config(&default_reg_path)?;
            return Ok(repo_config.repos.into_iter().map(|r| r.name).collect());
        }
    }

    Ok(Vec::new())
}

/// Clones a git repository into the local git root.
///
/// # Errors
///
/// Returns an error if:
/// - The target directory already exists.
/// - The `git clone` command fails.
/// - The user configuration cannot be updated.
pub fn clone_git_repo(url: &str) -> Result<()> {
    let git_root = get_git_root()?;
    fs::create_dir_all(&git_root)?;
    let repo_name = url
        .trim_end_matches('/')
        .split('/')
        .next_back()
        .unwrap_or("repo")
        .trim_end_matches(".git");
    let target = git_root.join(repo_name);
    if target.exists() {
        return Err(anyhow!(
            "Git repo '{repo_name}' already exists at {}",
            target.display()
        ));
    }
    println!("Cloning '{}' into {}...", url.cyan(), target.display());
    let status = std::process::Command::new("git")
        .arg("clone")
        .arg("--depth=1")
        .arg(url)
        .arg(&target)
        .status()?;
    if !status.success() {
        return Err(anyhow!("git clone failed"));
    }

    let mut config = read_config_from_path(&get_user_config_path()?)?;
    if !config.git_repos.iter().any(|repo_url| repo_url == url) {
        config.git_repos.push(url.to_string());
        write_user_config(&config)?;
    }

    println!(
        "Cloned git repo as '{}' (use with '#git@{}/<pkg>')",
        repo_name.green(),
        repo_name
    );
    Ok(())
}

/// Lists all cloned git repositories.
///
/// # Errors
///
/// Returns an error if the git root directory cannot be read.
pub fn list_git_repos() -> Result<Vec<String>> {
    let git_root = get_git_root()?;
    if !git_root.exists() {
        return Ok(Vec::new());
    }

    let mut repos = Vec::new();
    for entry in fs::read_dir(git_root)? {
        let entry = entry?;
        if entry.path().is_dir() {
            repos.push(entry.file_name().to_string_lossy().into_owned());
        }
    }
    repos.sort();
    Ok(repos)
}

/// Removes a cloned git repository.
///
/// # Errors
///
/// Returns an error if the repository is not found or cannot be removed.
pub fn remove_git_repo(repo_name: &str) -> Result<()> {
    let git_root = get_git_root()?;
    let target = git_root.join(repo_name);
    if !target.exists() {
        return Err(anyhow!("Git repository '{repo_name}' not found."));
    }

    let mut config = read_config_from_path(&get_user_config_path()?)?;
    let mut removed = false;
    config.git_repos.retain(|url| {
        let name_from_url = url
            .trim_end_matches('/')
            .split('/')
            .next_back()
            .unwrap_or_default()
            .trim_end_matches(".git");
        if name_from_url == repo_name {
            removed = true;
            false
        } else {
            true
        }
    });

    if removed {
        write_user_config(&config)?;
    }

    fs::remove_dir_all(&target)?;
    println!(
        "Removed git repository '{}' from {}",
        repo_name.green(),
        target.display()
    );
    Ok(())
}

/// Adds a cache mirror URL to the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the mirror already exists or the configuration cannot be
/// written.
pub fn add_cache_mirror(url: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    if config.cache_mirrors.iter().any(|existing| existing == url) {
        return Err(anyhow!("Cache mirror '{url}' already exists."));
    }
    config.cache_mirrors.push(url.to_string());
    write_user_config(&config)
}

/// Removes a cache mirror URL from the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the mirror is not found or the configuration cannot be
/// written.
pub fn remove_cache_mirror(url: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    if let Some(pos) = config
        .cache_mirrors
        .iter()
        .position(|existing| existing == url)
    {
        config.cache_mirrors.remove(pos);
        write_user_config(&config)
    } else {
        Err(anyhow!("Cache mirror '{url}' not found."))
    }
}

/// Sets the default registry URL in the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the configuration cannot be written.
pub fn set_default_registry(url: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    config.default_registry = Some(Registry {
        handle: String::new(),
        url: url.to_string(),
        advisory_prefix: None,
        authorities: None
    });
    write_user_config(&config)
}

/// Sets the default registry in the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the configuration cannot be written.
pub fn set_user_default_registry(
    default_registry: Option<Registry>
) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    config.default_registry = default_registry;
    write_user_config(&config)
}

/// Adds a registry URL to the list of added registries in the user-specific
/// configuration.
///
/// # Errors
///
/// Returns an error if the registry already exists or the configuration cannot
/// be written.
pub fn add_added_registry(url: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    if config.added_registries.iter().any(|r| r.url == url) {
        return Err(anyhow!("Registry with URL '{url}' already exists."));
    }
    config.added_registries.push(Registry {
        handle: String::new(),
        url: url.to_string(),
        advisory_prefix: None,
        authorities: None
    });
    write_user_config(&config)
}

/// Removes an added registry by its handle or URL.
///
/// # Errors
///
/// Returns an error if the registry is not found or the configuration cannot be
/// updated.
pub fn remove_added_registry(handle_or_url: &str) -> Result<()> {
    let mut config = read_config_from_path(&get_user_config_path()?)?;
    if let Some(pos) = config
        .added_registries
        .iter()
        .position(|r| r.handle == handle_or_url || r.url == handle_or_url)
    {
        let removed_registry = config.added_registries.remove(pos);
        if !removed_registry.handle.is_empty() {
            let db_root = get_db_root()?;
            let repo_path = db_root.join(removed_registry.handle);
            if repo_path.exists() {
                fs::remove_dir_all(repo_path)?;
            }
        }
        write_user_config(&config)
    } else {
        Err(anyhow!(
            "Added registry with handle or URL '{handle_or_url}' not found."
        ))
    }
}

/// Reads the repository configuration from the specified database path.
///
/// # Errors
///
/// Returns an error if `repo.yaml` is not found or cannot be parsed.
pub fn read_repo_config(db_path: &Path) -> Result<RepoConfig> {
    let config_path = db_path.join("repo.yaml");
    if !config_path.exists() {
        return Err(anyhow!(
            "repo.yaml not found in the root of the package database."
        ));
    }
    let content = fs::read_to_string(config_path)?;
    let config: RepoConfig = serde_yaml::from_str(&content)?;
    Ok(config)
}

/// Reads the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the configuration cannot be read or parsed.
pub fn read_user_config() -> Result<Config> {
    read_config_from_path(&get_user_config_path()?)
}

/// Updates the global package versions in the user-specific configuration.
///
/// # Errors
///
/// Returns an error if the configuration cannot be read or written.
pub fn update_global_versions<S: ::std::hash::BuildHasher>(
    versions: HashMap<String, String, S>
) -> Result<()> {
    let mut config = read_user_config()?;
    config.versions.extend(versions);
    write_user_config(&config)
}

/// Synchronizes the remote security policy if configured in system
/// `config.yaml`.
///
/// This allows organizations to manage security constraints (allowed/denied
/// lists) centrally. It verifies the policy's PGP signature before caching it
/// locally.
///
/// # Errors
///
/// Returns an error if:
/// - The configuration cannot be read.
/// - The system is in offline mode and a sync is required.
/// - The remote policy or its signature cannot be downloaded.
/// - The signature verification fails.
pub fn sync_remote_policy() -> Result<()> {
    let config = read_config()?;
    let Some(remote_cfg) = &config.remote_policy else {
        return Ok(());
    };

    println!("{} Syncing remote security policy...", "::".bold().blue());

    if crate::offline::is_offline() {
        return Err(anyhow!("Cannot sync remote policy in offline mode."));
    }

    let client = crate::utils::get_http_client()?;

    let policy_content = client.get(&remote_cfg.url).send()?.text()?;
    let sig_content = client.get(&remote_cfg.signature_url).send()?.bytes()?;

    let trusted_certs =
        crate::pgp::get_certs_by_name_or_fingerprint(&remote_cfg.trusted_keys)?;

    let temp_dir = tempfile::Builder::new().prefix("zoi-policy-").tempdir()?;
    let temp_policy_path = temp_dir.path().join("policy.yaml");
    let temp_sig_path = temp_dir.path().join("policy.yaml.sig");

    fs::write(&temp_policy_path, &policy_content)?;
    fs::write(&temp_sig_path, &sig_content)?;

    crate::pgp::verify_detached_signature_multi_key(
        &temp_policy_path,
        &temp_sig_path,
        trusted_certs
    )?;

    let cache_path = get_remote_policy_cache_path();
    if let Some(parent) = cache_path.parent() {
        fs::create_dir_all(parent)?;
    }
    fs::write(cache_path, policy_content)?;

    println!(
        "{}",
        "Remote policy verified and cached successfully.".green()
    );
    Ok(())
}

/// Merges a remote security policy into the local machine policy.
///
/// Precedence: If a field is already unoverridable in the base (machine)
/// policy, it remains so. Otherwise, the remote policy's unoverridable flags
/// and lists are added/merged into the local state.
fn merge_policies(
    base: &mut crate::types::Policy,
    remote: &crate::types::Policy
) {
    if remote.repos_unoverridable {
        base.repos_unoverridable = true;
    }
    if remote.telemetry_enabled_unoverridable {
        base.telemetry_enabled_unoverridable = true;
    }
    if remote.audit_log_enabled_unoverridable {
        base.audit_log_enabled_unoverridable = true;
    }
    if remote.rollback_enabled_unoverridable {
        base.rollback_enabled_unoverridable = true;
    }
    if remote.default_registry_unoverridable {
        base.default_registry_unoverridable = true;
    }
    if remote.added_registries_unoverridable {
        base.added_registries_unoverridable = true;
    }
    if remote.git_repos_unoverridable {
        base.git_repos_unoverridable = true;
    }
    if remote.allow_deny_lists_unoverridable {
        base.allow_deny_lists_unoverridable = true;
    }
    if remote.signature_enforcement_unoverridable {
        base.signature_enforcement_unoverridable = true;
    }
    if remote.protect_db_unoverridable {
        base.protect_db_unoverridable = true;
    }
    if remote.max_resolution_depth_unoverridable {
        base.max_resolution_depth_unoverridable = true;
    }
    if remote.offline_mode_unoverridable {
        base.offline_mode_unoverridable = true;
    }
    if remote.pkg_dirs_unoverridable {
        base.pkg_dirs_unoverridable = true;
    }
    if remote.cache_mirrors_unoverridable {
        base.cache_mirrors_unoverridable = true;
    }
    if remote.jobs_unoverridable {
        base.jobs_unoverridable = true;
    }
    if remote.advisory_enforcement_unoverridable {
        base.advisory_enforcement_unoverridable = true;
    }

    if let Some(allowed) = &remote.allowed_licenses {
        base.allowed_licenses
            .get_or_insert_with(Vec::new)
            .extend(allowed.clone());
    }
    if let Some(denied) = &remote.denied_licenses {
        base.denied_licenses
            .get_or_insert_with(Vec::new)
            .extend(denied.clone());
    }
    if let Some(allowed) = &remote.allowed_packages {
        base.allowed_packages
            .get_or_insert_with(Vec::new)
            .extend(allowed.clone());
    }
    if let Some(denied) = &remote.denied_packages {
        base.denied_packages
            .get_or_insert_with(Vec::new)
            .extend(denied.clone());
    }
    if let Some(allowed) = &remote.allowed_repos {
        base.allowed_repos
            .get_or_insert_with(Vec::new)
            .extend(allowed.clone());
    }
    if let Some(denied) = &remote.denied_repos {
        base.denied_repos
            .get_or_insert_with(Vec::new)
            .extend(denied.clone());
    }

    if let Some(remote_sig) = &remote.signature_enforcement {
        if let Some(ref mut base_sig) = base.signature_enforcement {
            if remote_sig.enable {
                base_sig.enable = true;
            }
            base_sig
                .trusted_keys
                .extend(remote_sig.trusted_keys.clone());
            base_sig.trusted_keys.sort();
            base_sig.trusted_keys.dedup();
        } else {
            base.signature_enforcement = Some(remote_sig.clone());
        }
    }
}