git-iris 2.0.9

//! Agent setup service for Git-Iris
//!
//! This service handles all the setup and initialization for the agent framework,
//! including configuration loading, client creation, and agent setup.

use anyhow::Result;
use std::sync::Arc;

use crate::agents::context::TaskContext;
use crate::agents::iris::StructuredResponse;
use crate::agents::tools::with_active_repo_root;
use crate::agents::{AgentBackend, IrisAgent, IrisAgentBuilder};
use crate::common::CommonParams;
use crate::config::Config;
use crate::git::GitRepo;
use crate::providers::Provider;

/// Service for setting up agents with proper configuration
pub struct AgentSetupService {
    config: Config,
    git_repo: Option<GitRepo>,
}

impl AgentSetupService {
    /// Create a new setup service with the given configuration
    #[must_use]
    pub fn new(config: Config) -> Self {
        Self {
            config,
            git_repo: None,
        }
    }

    /// Create setup service from common parameters (following existing patterns)
    ///
    /// # Errors
    ///
    /// Returns an error when config loading, argument application, or repository setup fails.
    pub fn from_common_params(
        common_params: &CommonParams,
        repository_url: Option<String>,
    ) -> Result<Self> {
        let mut config = Config::load()?;

        // Apply common parameters to config (following existing pattern)
        common_params.apply_to_config(&mut config)?;

        let mut setup_service = Self::new(config);

        // Setup git repo if needed
        if let Some(repo_url) = repository_url {
            // Handle remote repository setup (following existing pattern)
            setup_service.git_repo = Some(GitRepo::new_from_url(Some(repo_url))?);
        } else {
            // Use local repository
            setup_service.git_repo = Some(GitRepo::new(&std::env::current_dir()?)?);
        }

        Ok(setup_service)
    }

    /// Create a configured Iris agent
    ///
    /// # Errors
    ///
    /// Returns an error when provider validation or agent construction fails.
    pub fn create_iris_agent(&mut self) -> Result<IrisAgent> {
        let backend = AgentBackend::from_config(&self.config)?;
        // Validate environment (API keys etc) before creating agent
        self.validate_provider(&backend)?;

        let mut agent = IrisAgentBuilder::new()
            .with_provider(&backend.provider_name)
            .with_model(&backend.model)
            .build()?;

        // Pass config and fast model to agent
        agent.set_config(self.config.clone());
        agent.set_fast_model(backend.fast_model);

        Ok(agent)
    }

    /// Validate provider configuration (API keys etc)
    fn validate_provider(&self, backend: &AgentBackend) -> Result<()> {
        let provider: Provider = backend
            .provider_name
            .parse()
            .map_err(|_| anyhow::anyhow!("Unsupported provider: {}", backend.provider_name))?;

        // Check API key - from config or environment
        let has_api_key = self
            .config
            .get_provider_config(provider.name())
            .is_some_and(crate::providers::ProviderConfig::has_api_key);

        if !has_api_key && std::env::var(provider.api_key_env()).is_err() {
            return Err(anyhow::anyhow!(
                "No API key found for {}. Set {} or configure in ~/.config/git-iris/config.toml",
                provider.name(),
                provider.api_key_env()
            ));
        }

        Ok(())
    }

    /// Get the git repository instance
    #[must_use]
    pub fn git_repo(&self) -> Option<&GitRepo> {
        self.git_repo.as_ref()
    }

    /// Get the configuration
    #[must_use]
    pub fn config(&self) -> &Config {
        &self.config
    }
}

/// High-level function to handle tasks with agents using a common pattern
/// This is a convenience function that sets up an agent and executes a task
///
/// # Errors
///
/// Returns an error when setup, agent execution, or the caller-provided handler fails.
pub async fn handle_with_agent<F, Fut, T>(
    common_params: CommonParams,
    repository_url: Option<String>,
    capability: &str,
    task_prompt: &str,
    handler: F,
) -> Result<T>
where
    F: FnOnce(crate::agents::iris::StructuredResponse) -> Fut,
    Fut: std::future::Future<Output = Result<T>>,
{
    // Create setup service
    let mut setup_service = AgentSetupService::from_common_params(&common_params, repository_url)?;

    // Create agent
    let mut agent = setup_service.create_iris_agent()?;

    // Execute task with capability - now returns StructuredResponse
    let result = agent.execute_task(capability, task_prompt).await?;

    // Call the handler with the result
    handler(result).await
}

/// Simple factory function for creating agents with minimal configuration
///
/// # Errors
///
/// Returns an error when the provider configuration is invalid or agent construction fails.
pub fn create_agent_with_defaults(provider: &str, model: &str) -> Result<IrisAgent> {
    IrisAgentBuilder::new()
        .with_provider(provider)
        .with_model(model)
        .build()
}

/// Create an agent from environment variables
///
/// # Errors
///
/// Returns an error when agent construction fails.
pub fn create_agent_from_env() -> Result<IrisAgent> {
    let provider_str = std::env::var("IRIS_PROVIDER").unwrap_or_else(|_| "openai".to_string());
    let provider: Provider = provider_str.parse().unwrap_or_default();

    let model =
        std::env::var("IRIS_MODEL").unwrap_or_else(|_| provider.default_model().to_string());

    create_agent_with_defaults(provider.name(), &model)
}

// =============================================================================
// IrisAgentService - The primary interface for agent task execution
// =============================================================================

/// High-level service for executing agent tasks with structured context.
///
/// This is the primary interface for all agent-based operations in git-iris.
/// It handles:
/// - Configuration management
/// - Agent lifecycle
/// - Task context validation and formatting
/// - Environment validation
///
/// # Example
/// ```ignore
/// let service = IrisAgentService::from_common_params(&params, None)?;
/// let context = TaskContext::for_gen();
/// let result = service.execute_task("commit", context).await?;
/// ```
pub struct IrisAgentService {
    config: Config,
    git_repo: Option<Arc<GitRepo>>,
    provider: String,
    model: String,
    fast_model: String,
}

impl IrisAgentService {
    /// Create a new service with explicit provider configuration
    #[must_use]
    pub fn new(config: Config, provider: String, model: String, fast_model: String) -> Self {
        Self {
            config,
            git_repo: None,
            provider,
            model,
            fast_model,
        }
    }

    /// Create service from common CLI parameters
    ///
    /// This is the primary constructor for CLI usage. It:
    /// - Loads and applies configuration
    /// - Sets up the git repository (local or remote)
    /// - Validates the environment
    ///
    /// # Errors
    ///
    /// Returns an error when config loading, agent backend resolution, or repository setup fails.
    pub fn from_common_params(
        common_params: &CommonParams,
        repository_url: Option<String>,
    ) -> Result<Self> {
        let mut config = Config::load()?;
        common_params.apply_to_config(&mut config)?;

        // Determine backend (provider/model) from config
        let backend = AgentBackend::from_config(&config)?;

        let mut service = Self::new(
            config,
            backend.provider_name,
            backend.model,
            backend.fast_model,
        );

        // Setup git repo
        if let Some(repo_url) = repository_url {
            service.git_repo = Some(Arc::new(GitRepo::new_from_url(Some(repo_url))?));
        } else {
            service.git_repo = Some(Arc::new(GitRepo::new(&std::env::current_dir()?)?));
        }

        Ok(service)
    }

    /// Check that the environment is properly configured
    ///
    /// # Errors
    ///
    /// Returns an error when the active provider configuration is incomplete.
    pub fn check_environment(&self) -> Result<()> {
        self.config.check_environment()
    }

    /// Execute an agent task with structured context
    ///
    /// # Arguments
    /// * `capability` - The capability to invoke (e.g., "commit", "review", "pr")
    /// * `context` - Structured context describing what to analyze
    ///
    /// # Returns
    /// The structured response from the agent
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or task execution fails.
    pub async fn execute_task(
        &self,
        capability: &str,
        context: TaskContext,
    ) -> Result<StructuredResponse> {
        let run_task = async {
            let mut agent = self.create_agent()?;
            let task_prompt = Self::build_task_prompt(
                capability,
                &context,
                self.config.temp_instructions.as_deref(),
            );
            agent.execute_task(capability, &task_prompt).await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Execute a task with a custom prompt (for backwards compatibility)
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or task execution fails.
    pub async fn execute_task_with_prompt(
        &self,
        capability: &str,
        task_prompt: &str,
    ) -> Result<StructuredResponse> {
        let run_task = async {
            let mut agent = self.create_agent()?;
            agent.execute_task(capability, task_prompt).await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Execute an agent task with style overrides
    ///
    /// Allows runtime override of preset and gitmoji settings without
    /// modifying the underlying config. Useful for UI flows where the
    /// user can change settings per-invocation.
    ///
    /// # Arguments
    /// * `capability` - The capability to invoke
    /// * `context` - Structured context describing what to analyze
    /// * `preset` - Optional preset name override (e.g., "conventional", "cosmic")
    /// * `use_gitmoji` - Optional gitmoji setting override
    /// * `instructions` - Optional custom instructions from the user
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or task execution fails.
    pub async fn execute_task_with_style(
        &self,
        capability: &str,
        context: TaskContext,
        preset: Option<&str>,
        use_gitmoji: Option<bool>,
        instructions: Option<&str>,
    ) -> Result<StructuredResponse> {
        let run_task = async {
            let mut config = self.config.clone();
            if let Some(p) = preset {
                config.temp_preset = Some(p.to_string());
            }
            if let Some(gitmoji) = use_gitmoji {
                config.use_gitmoji = gitmoji;
            }

            let mut agent = IrisAgentBuilder::new()
                .with_provider(&self.provider)
                .with_model(&self.model)
                .build()?;
            agent.set_config(config);
            agent.set_fast_model(self.fast_model.clone());

            let task_prompt = Self::build_task_prompt(capability, &context, instructions);
            agent.execute_task(capability, &task_prompt).await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Build a task prompt incorporating the context information and optional instructions
    fn build_task_prompt(
        capability: &str,
        context: &TaskContext,
        instructions: Option<&str>,
    ) -> String {
        let context_json = context.to_prompt_context();
        let diff_hint = context.diff_hint();

        // Build instruction suffix if provided
        let instruction_suffix = instructions
            .filter(|i| !i.trim().is_empty())
            .map(|i| format!("\n\n## Custom Instructions\n{}", i))
            .unwrap_or_default();

        // Extract version and date info if this is a Changelog context
        let version_info = if let TaskContext::Changelog {
            version_name, date, ..
        } = context
        {
            let version_str = version_name
                .as_ref()
                .map_or_else(|| "(derive from git refs)".to_string(), String::clone);
            format!(
                "\n\n## Version Information\n- Version: {}\n- Release Date: {}\n\nIMPORTANT: Use the exact version name and date provided above. Do NOT guess or make up version numbers or dates.",
                version_str, date
            )
        } else {
            String::new()
        };
        let existing_pr_body = context.existing_pull_request_body().map_or_else(
            String::new,
            |body| {
                format!(
                    "\n\n## Existing Pull Request Description\nRevise this existing PR description instead of blindly replacing it. Preserve accurate reviewer-facing sections, remove stale content, and update it for the current changes:\n\n----- BEGIN EXISTING PR DESCRIPTION -----\n{body}\n----- END EXISTING PR DESCRIPTION -----"
                )
            },
        );
        let pr_template = context.pull_request_template().map_or_else(
            String::new,
            |template| {
                format!(
                    "\n\n## Pull Request Template\nAdapt the generated description around this GitHub PR template from `{}`. Preserve the template's required headings, checklist items, and prompts when they apply. Fill useful sections with evidence from the changes, remove placeholder text, and omit sections only when they are clearly irrelevant:\n\n----- BEGIN PR TEMPLATE -----\n{}\n----- END PR TEMPLATE -----",
                    template.path, template.body
                )
            },
        );

        match capability {
            "commit" => format!(
                "Generate a commit message for the following context:\n{}\n\nUse: {}{}",
                context_json, diff_hint, instruction_suffix
            ),
            "review" => format!(
                "Review the code changes for the following context:\n{}\n\nUse: {}{}",
                context_json, diff_hint, instruction_suffix
            ),
            "pr" => format!(
                "Generate a pull request description for:\n{}\n\nUse: {}{}{}{}",
                context_json, diff_hint, pr_template, existing_pr_body, instruction_suffix
            ),
            "changelog" => format!(
                "Generate a changelog for:\n{}\n\nUse: {}{}{}",
                context_json, diff_hint, version_info, instruction_suffix
            ),
            "release_notes" => format!(
                "Generate release notes for:\n{}\n\nUse: {}{}{}",
                context_json, diff_hint, version_info, instruction_suffix
            ),
            _ => format!(
                "Execute task with context:\n{}\n\nHint: {}{}",
                context_json, diff_hint, instruction_suffix
            ),
        }
    }

    /// Create a configured Iris agent
    fn create_agent(&self) -> Result<IrisAgent> {
        let mut agent = IrisAgentBuilder::new()
            .with_provider(&self.provider)
            .with_model(&self.model)
            .build()?;

        // Pass config and fast model to agent
        agent.set_config(self.config.clone());
        agent.set_fast_model(self.fast_model.clone());

        Ok(agent)
    }

    /// Create a configured Iris agent with content update tools (for Studio chat)
    fn create_agent_with_content_updates(
        &self,
        sender: crate::agents::tools::ContentUpdateSender,
    ) -> Result<IrisAgent> {
        let mut agent = self.create_agent()?;
        agent.set_content_update_sender(sender);
        Ok(agent)
    }

    /// Execute a chat task with content update capabilities
    ///
    /// This is used by Studio to enable Iris to update content via tool calls.
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or chat execution fails.
    pub async fn execute_chat_with_updates(
        &self,
        task_prompt: &str,
        content_update_sender: crate::agents::tools::ContentUpdateSender,
    ) -> Result<StructuredResponse> {
        let run_task = async {
            let mut agent = self.create_agent_with_content_updates(content_update_sender)?;
            agent.execute_task("chat", task_prompt).await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Execute a chat task with streaming and content update capabilities
    ///
    /// Combines streaming output with tool-based content updates for the TUI chat.
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or chat streaming fails.
    pub async fn execute_chat_streaming<F>(
        &self,
        task_prompt: &str,
        content_update_sender: crate::agents::tools::ContentUpdateSender,
        on_chunk: F,
    ) -> Result<StructuredResponse>
    where
        F: FnMut(&str, &str) + Send,
    {
        let run_task = async {
            let mut agent = self.create_agent_with_content_updates(content_update_sender)?;
            agent
                .execute_task_streaming("chat", task_prompt, on_chunk)
                .await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Execute an agent task with streaming
    ///
    /// This method streams LLM output in real-time, calling the callback with each
    /// text chunk as it arrives. Ideal for TUI display of generation progress.
    ///
    /// # Arguments
    /// * `capability` - The capability to invoke (e.g., "review", "pr", "changelog")
    /// * `context` - Structured context describing what to analyze
    /// * `on_chunk` - Callback receiving `(chunk, aggregated_text)` for each delta
    ///
    /// # Returns
    /// The final structured response after streaming completes
    ///
    /// # Errors
    ///
    /// Returns an error when agent construction or streaming execution fails.
    pub async fn execute_task_streaming<F>(
        &self,
        capability: &str,
        context: TaskContext,
        on_chunk: F,
    ) -> Result<StructuredResponse>
    where
        F: FnMut(&str, &str) + Send,
    {
        let run_task = async {
            let mut agent = self.create_agent()?;
            let task_prompt = Self::build_task_prompt(
                capability,
                &context,
                self.config.temp_instructions.as_deref(),
            );
            agent
                .execute_task_streaming(capability, &task_prompt, on_chunk)
                .await
        };

        if let Some(repo) = &self.git_repo {
            with_active_repo_root(repo.repo_path(), run_task).await
        } else {
            run_task.await
        }
    }

    /// Get the configuration
    #[must_use]
    pub fn config(&self) -> &Config {
        &self.config
    }

    /// Get a mutable reference to the configuration
    pub fn config_mut(&mut self) -> &mut Config {
        &mut self.config
    }

    /// Attach a git repository to this service
    pub fn set_git_repo(&mut self, repo: GitRepo) {
        self.git_repo = Some(Arc::new(repo));
    }

    /// Get the git repository if available
    #[must_use]
    pub fn git_repo(&self) -> Option<&Arc<GitRepo>> {
        self.git_repo.as_ref()
    }

    /// Get the provider name
    #[must_use]
    pub fn provider(&self) -> &str {
        &self.provider
    }

    /// Get the model name
    #[must_use]
    pub fn model(&self) -> &str {
        &self.model
    }

    /// Get the fast model name (for subagents and simple tasks)
    #[must_use]
    pub fn fast_model(&self) -> &str {
        &self.fast_model
    }

    /// Get the API key for the current provider from config
    #[must_use]
    pub fn api_key(&self) -> Option<String> {
        self.config
            .get_provider_config(&self.provider)
            .and_then(|pc| pc.api_key_if_set())
            .map(String::from)
    }
}