use codex_connectors::parse_plugin_app_config;
use codex_core_plugins::ResolvedExecutorPlugin;
use codex_plugin::AppDeclaration;
use codex_plugin::PluginResourceLocator;
use codex_utils_path_uri::PathUri;
use std::io;
use thiserror::Error;

/// Loads connector declarations from a resolved plugin through its owning executor.
#[derive(Clone, Copy, Debug, Default)]
pub struct ExecutorPluginConnectorProvider;

/// Failure to load connector declarations from an executor plugin.
#[derive(Debug, Error)]
pub enum ExecutorPluginConnectorProviderError {
    #[error("failed to read app config for selected plugin `{plugin_id}` at `{path}`: {source}")]
    ReadConfig {
        plugin_id: String,
        path: PathUri,
        #[source]
        source: io::Error,
    },
    #[error("failed to parse app config for selected plugin `{plugin_id}` at `{path}`: {source}")]
    ParseConfig {
        plugin_id: String,
        path: PathUri,
        #[source]
        source: serde_json::Error,
    },
}

impl ExecutorPluginConnectorProvider {
    /// Returns the connector declarations contributed by `plugin`.
    pub async fn load(
        &self,
        plugin: &ResolvedExecutorPlugin,
    ) -> Result<Vec<AppDeclaration>, ExecutorPluginConnectorProviderError> {
        let resolved_plugin = plugin.plugin();
        let plugin_id = resolved_plugin.selected_root_id();
        let Some(PluginResourceLocator::Environment {
            path: config_path, ..
        }) = resolved_plugin.manifest().paths.apps.as_ref()
        else {
            return Ok(Vec::new());
        };
        let contents = plugin
            .file_system()
            .read_file_text(config_path, /*sandbox*/ None)
            .await
            .map_err(|source| ExecutorPluginConnectorProviderError::ReadConfig {
                plugin_id: plugin_id.to_string(),
                path: config_path.clone(),
                source,
            })?;

        parse_plugin_app_config(&contents).map_err(|source| {
            ExecutorPluginConnectorProviderError::ParseConfig {
                plugin_id: plugin_id.to_string(),
                path: config_path.clone(),
                source,
            }
        })
    }
}