use std::collections::HashMap;
use std::collections::HashSet;
use std::fs;
use std::path::Path;
use std::path::PathBuf;
use std::sync::Arc;
use std::sync::Mutex;

use crate::OPENAI_API_CURATED_MARKETPLACE_NAME;
use crate::OPENAI_CURATED_MARKETPLACE_NAME;
use crate::PluginsConfigInput;
use crate::PluginsManager;
use crate::http_client_selector::HttpClientSelector;
use crate::remote::RemotePluginServiceConfig;
use codex_config::LoaderOverrides;
use codex_config::NoopThreadConfigLoader;
use codex_config::loader::load_config_layers_state;
use codex_exec_server::LOCAL_FS;
use codex_http_client::ClientRouteClass;
use codex_http_client::HttpClientFactory;
use codex_http_client::OutboundProxyPolicy;
use codex_http_client::RouteAwareClientPool;
use codex_http_client::RouteAwareRequestBuilder;
use codex_protocol::auth::AuthMode;
use codex_protocol::protocol::Product;
use codex_protocol::protocol::SkillScope;
use codex_skills::LoadedSkillRoot;
use codex_skills::LoadedSkills;
use codex_skills::SkillError;
use codex_skills::SkillLoadFuture;
use codex_skills::SkillMetadata;
use codex_skills::SkillRootLoadRequest;
use codex_skills::SkillRootLoader;
use codex_skills::parse_skill_frontmatter_metadata;
use codex_utils_absolute_path::AbsolutePathBuf;
use codex_utils_plugins::PluginSkillRoot;
use codex_utils_plugins::SkillDiscoveryMode;
use codex_utils_plugins::migrated_command_skills_root;
use http::Method;
use toml::Value;

pub(crate) const TEST_CURATED_PLUGIN_SHA: &str = "0123456789abcdef0123456789abcdef01234567";
pub(crate) const TEST_CURATED_PLUGIN_CACHE_VERSION: &str = "01234567";

pub(crate) fn test_plugins_manager(codex_home: PathBuf) -> PluginsManager {
    PluginsManager::new(
        codex_home,
        /*auth_mode*/ None,
        test_skill_root_loader(),
    )
}

pub(crate) fn test_plugins_manager_with_options(
    codex_home: PathBuf,
    restriction_product: Option<Product>,
    auth_mode: Option<AuthMode>,
) -> PluginsManager {
    PluginsManager::new_with_options(
        codex_home,
        restriction_product,
        auth_mode,
        test_skill_root_loader(),
    )
}

pub(crate) fn test_skill_root_loader() -> Arc<dyn SkillRootLoader<PluginSkillRoot>> {
    Arc::new(TestSkillRootLoader)
}

struct TestSkillRootLoader;

impl SkillRootLoader<PluginSkillRoot> for TestSkillRootLoader {
    fn load_roots(
        &self,
        request: SkillRootLoadRequest<PluginSkillRoot>,
    ) -> SkillLoadFuture<'_, LoadedSkills> {
        Box::pin(async move {
            let mut loaded_roots = Vec::new();
            for root in request.roots {
                let cached = request
                    .snapshots
                    .as_ref()
                    .and_then(|cache| cache.get(&root));
                let snapshot = match cached {
                    Some(snapshot) => snapshot,
                    None => {
                        let snapshot = load_test_skill_root(&root);
                        if let Some(snapshots) = &request.snapshots {
                            snapshots.insert(root.clone(), snapshot.clone());
                        }
                        snapshot
                    }
                };
                let migrated_root = migrated_command_skills_root(&root.plugin_root);
                let canonical_migrated_root = fs::canonicalize(migrated_root.as_path())
                    .ok()
                    .and_then(|path| AbsolutePathBuf::from_absolute_path_checked(path).ok())
                    .unwrap_or(migrated_root);
                loaded_roots.push((snapshot.root == canonical_migrated_root, snapshot));
            }

            let native_names = loaded_roots
                .iter()
                .filter(|(migrated, _)| !migrated)
                .flat_map(|(_, snapshot)| &snapshot.skills)
                .map(|skill| (skill.plugin_id.clone(), skill.name.clone()))
                .collect::<HashSet<_>>();
            let mut seen_paths = HashSet::new();
            let mut outcome = LoadedSkills::default();
            for (migrated, snapshot) in loaded_roots {
                outcome
                    .skills
                    .extend(snapshot.skills.into_iter().filter(|skill| {
                        (!migrated
                            || !native_names
                                .contains(&(skill.plugin_id.clone(), skill.name.clone())))
                            && skill.matches_product_restriction_for_product(
                                request.restriction_product,
                            )
                            && seen_paths.insert(skill.path_to_skills_md.clone())
                    }));
                outcome.errors.extend(snapshot.errors);
            }
            outcome.skills.sort_by(|left, right| {
                left.name
                    .cmp(&right.name)
                    .then_with(|| left.path_to_skills_md.cmp(&right.path_to_skills_md))
            });
            outcome
        })
    }
}

fn load_test_skill_root(root: &PluginSkillRoot) -> LoadedSkillRoot {
    let canonical_root = fs::canonicalize(root.path.as_path())
        .ok()
        .and_then(|path| AbsolutePathBuf::from_absolute_path_checked(path).ok())
        .unwrap_or_else(|| root.path.clone());
    let mut skills = Vec::new();
    let mut errors = Vec::new();
    let mut discovery_paths = HashMap::new();
    let mut directories = vec![root.path.clone()];
    while let Some(directory) = directories.pop() {
        let Ok(entries) = fs::read_dir(directory.as_path()) else {
            continue;
        };
        for entry in entries.flatten() {
            let path = entry.path();
            if path.is_dir() {
                if (root.discovery_mode == SkillDiscoveryMode::Recursive || directory == root.path)
                    && let Ok(path) = AbsolutePathBuf::from_absolute_path_checked(path)
                {
                    directories.push(path);
                }
                continue;
            }
            if path.file_name().is_none_or(|name| name != "SKILL.md")
                || (root.discovery_mode == SkillDiscoveryMode::DirectChildren
                    && directory == root.path)
            {
                continue;
            }
            let Ok(path) = AbsolutePathBuf::from_absolute_path_checked(path) else {
                continue;
            };
            let canonical_path = fs::canonicalize(path.as_path())
                .ok()
                .and_then(|path| AbsolutePathBuf::from_absolute_path_checked(path).ok())
                .unwrap_or_else(|| path.clone());
            let parsed = fs::read_to_string(path.as_path())
                .map_err(|error| error.to_string())
                .and_then(|contents| {
                    parse_skill_frontmatter_metadata(&contents, || {
                        directory
                            .as_path()
                            .file_name()
                            .and_then(|name| name.to_str())
                            .unwrap_or_default()
                            .to_string()
                    })
                    .map_err(|error| error.to_string())
                });
            match parsed {
                Ok(parsed) => {
                    discovery_paths.insert(canonical_path.clone(), path);
                    skills.push(SkillMetadata {
                        name: format!("{}:{}", root.plugin_namespace, parsed.name),
                        description: parsed.description,
                        short_description: parsed.short_description,
                        interface: None,
                        dependencies: None,
                        policy: None,
                        path_to_skills_md: canonical_path,
                        scope: SkillScope::User,
                        plugin_id: Some(root.plugin_identity.plugin_id.clone()),
                        remote_plugin_id: root.plugin_identity.remote_plugin_id.clone(),
                    });
                }
                Err(message) => errors.push(SkillError {
                    path: canonical_path,
                    message,
                }),
            }
        }
    }

    LoadedSkillRoot {
        root: canonical_root,
        skills,
        skill_discovery_path_by_path: Arc::new(discovery_paths),
        errors,
        is_agent_plugin: root.discovery_mode == SkillDiscoveryMode::DirectChildren,
    }
}

pub(crate) fn test_http_client_factory() -> HttpClientFactory {
    HttpClientFactory::new(OutboundProxyPolicy::ReqwestDefault)
}

#[derive(Debug)]
pub(crate) struct RecordingHttpClientSelector {
    selected_urls: Arc<Mutex<Vec<String>>>,
    delegate: RouteAwareClientPool,
}

impl RecordingHttpClientSelector {
    pub(crate) fn new() -> (Arc<Self>, Arc<Mutex<Vec<String>>>) {
        let selected_urls = Arc::new(Mutex::new(Vec::new()));
        let delegate = RouteAwareClientPool::with_chatgpt_cloudflare_cookies(
            test_http_client_factory(),
            ClientRouteClass::Api,
        );
        (
            Arc::new(Self {
                selected_urls: Arc::clone(&selected_urls),
                delegate,
            }),
            selected_urls,
        )
    }
}

impl HttpClientSelector for RecordingHttpClientSelector {
    fn request(&self, method: Method, url: &str) -> RouteAwareRequestBuilder {
        match self.selected_urls.lock() {
            Ok(mut selected_urls) => selected_urls.push(url.to_string()),
            Err(error) => panic!("selected URL recorder lock should not be poisoned: {error}"),
        }
        self.delegate.request(method, url)
    }
    fn outbound_proxy_policy(&self) -> OutboundProxyPolicy {
        self.delegate.outbound_proxy_policy()
    }
}

pub(crate) fn recording_remote_plugin_service_config(
    chatgpt_base_url: String,
) -> (RemotePluginServiceConfig, Arc<Mutex<Vec<String>>>) {
    let (http_clients, selected_urls) = RecordingHttpClientSelector::new();
    (
        RemotePluginServiceConfig {
            chatgpt_base_url,
            http_clients,
        },
        selected_urls,
    )
}

pub(crate) fn recorded_http_client_urls(selected_urls: &Mutex<Vec<String>>) -> Vec<String> {
    match selected_urls.lock() {
        Ok(selected_urls) => selected_urls.clone(),
        Err(error) => panic!("selected URL recorder lock should not be poisoned: {error}"),
    }
}

pub(crate) fn write_file(path: &Path, contents: &str) {
    fs::create_dir_all(path.parent().expect("file should have a parent")).unwrap();
    fs::write(path, contents).unwrap();
}

pub(crate) fn write_curated_plugin(root: &Path, plugin_name: &str) {
    let plugin_root = root.join("plugins").join(plugin_name);
    write_file(
        &plugin_root.join(".codex-plugin/plugin.json"),
        &format!(
            r#"{{
  "name": "{plugin_name}",
  "description": "Plugin that includes skills, MCP servers, and app connectors"
}}"#
        ),
    );
    write_file(
        &plugin_root.join("skills/SKILL.md"),
        "---\nname: sample\ndescription: sample\n---\n",
    );
    write_file(
        &plugin_root.join(".mcp.json"),
        r#"{
  "mcpServers": {
    "sample-docs": {
      "type": "http",
      "url": "https://sample.example/mcp"
    }
  }
}"#,
    );
    write_file(
        &plugin_root.join(".app.json"),
        r#"{
  "apps": {
    "calendar": {
      "id": "connector_calendar"
    }
  }
}"#,
    );
}

pub(crate) fn write_openai_curated_marketplace(root: &Path, plugin_names: &[&str]) {
    write_curated_marketplace(
        root,
        "marketplace.json",
        OPENAI_CURATED_MARKETPLACE_NAME,
        /*display_name*/ None,
        plugin_names,
    );
}

pub(crate) fn write_openai_api_curated_marketplace(root: &Path, plugin_names: &[&str]) {
    write_curated_marketplace(
        root,
        "api_marketplace.json",
        OPENAI_API_CURATED_MARKETPLACE_NAME,
        Some("OpenAI Curated"),
        plugin_names,
    );
}

fn write_curated_marketplace(
    root: &Path,
    manifest_name: &str,
    marketplace_name: &str,
    display_name: Option<&str>,
    plugin_names: &[&str],
) {
    let plugins = plugin_names
        .iter()
        .map(|plugin_name| {
            format!(
                r#"{{
      "name": "{plugin_name}",
      "source": {{
        "source": "local",
        "path": "./plugins/{plugin_name}"
      }}
    }}"#
            )
        })
        .collect::<Vec<_>>()
        .join(",\n");
    let interface = display_name
        .map(|display_name| {
            format!(
                r#"
  "interface": {{
    "displayName": "{display_name}"
  }},"#
            )
        })
        .unwrap_or_default();
    write_file(
        &root.join(".agents/plugins").join(manifest_name),
        &format!(
            r#"{{
  "name": "{marketplace_name}",{interface}
  "plugins": [
{plugins}
  ]
}}"#
        ),
    );
    for plugin_name in plugin_names {
        write_curated_plugin(root, plugin_name);
    }
}

pub(crate) fn write_curated_plugin_sha_with(codex_home: &Path, sha: &str) {
    write_file(&codex_home.join(".tmp/plugins.sha"), &format!("{sha}\n"));
}

pub(crate) async fn load_plugins_config(codex_home: &Path, cwd: &Path) -> PluginsConfigInput {
    let codex_home = AbsolutePathBuf::try_from(codex_home).expect("codex home should be absolute");
    let cwd = AbsolutePathBuf::try_from(cwd).expect("cwd should be absolute");
    let config_layer_stack = load_config_layers_state(
        LOCAL_FS.as_ref(),
        codex_home.as_path(),
        Some(cwd),
        &[],
        LoaderOverrides::without_managed_config_for_tests(),
        &NoopThreadConfigLoader,
    )
    .await
    .expect("config should load");
    let effective_config = config_layer_stack.effective_config();
    let model_provider_id = effective_config
        .get("model_provider")
        .and_then(toml::Value::as_str)
        .unwrap_or_default()
        .to_string();
    PluginsConfigInput::new(
        config_layer_stack,
        model_provider_id,
        feature_enabled(&effective_config, "plugins", /*default_enabled*/ true),
        feature_enabled(
            &effective_config,
            "remote_plugin",
            /*default_enabled*/ true,
        ),
        "https://chatgpt.com/backend-api/".to_string(),
        test_http_client_factory(),
    )
}

fn feature_enabled(config: &Value, key: &str, default_enabled: bool) -> bool {
    config
        .get("features")
        .and_then(Value::as_table)
        .and_then(|features| features.get(key))
        .and_then(Value::as_bool)
        .unwrap_or(default_enabled)
}