lmrc-cli 0.3.16

//! Application template generation module
//!
//! This module handles generation of applications from embedded templates.
//! It supports multiple template types: gateway (with auth), api (without auth), and migrator.

use colored::Colorize;
use include_dir::{Dir, include_dir};
use lmrc_config_validator::{AppType, ApplicationEntry, LmrcConfig};
use std::fs;
use std::path::Path;

use crate::error::Result;

// Embed template directories at compile time (from embedded-apps/ directory within CLI crate)
static API_SERVICE_TEMPLATE: Dir =
    include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/api-service-template");

// Embed infrastructure apps (ready-to-use, no templating)
static GATEWAY_APP: Dir = include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/gateway");
static INFRA_API_APP: Dir = include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/infra-api");
static INFRA_MIGRATOR_APP: Dir = include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/infra-migrator");
static APP_MIGRATOR_APP: Dir = include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/app-migrator");
static INFRA_FRONT_APP: Dir = include_dir!("$CARGO_MANIFEST_DIR/embedded-apps/infra-front");

/// Generate all applications from config
pub fn generate_applications(project_path: &Path, config: &LmrcConfig) -> Result<()> {
    // First, bundle infrastructure apps (always included)
    bundle_infrastructure_apps(project_path)?;

    // Then generate user-defined applications
    for app in &config.apps.applications {
        generate_single_app_internal(project_path, app, config)?;
    }
    Ok(())
}

/// Generate a single application by name and type (for `lmrc add app` command)
pub fn generate_single_app(
    project_path: &Path,
    app_name: &str,
    app_type: Option<&AppType>,
) -> Result<()> {
    let app = ApplicationEntry {
        name: app_name.to_string(),
        app_type: app_type.cloned(),
        docker: None,
        deployment: None,
    };

    // Create a minimal config for templating
    let config = create_minimal_config_for_templating(app_name);

    generate_single_app_internal(project_path, &app, &config)
}

fn create_minimal_config_for_templating(app_name: &str) -> LmrcConfig {
    use lmrc_config_validator::*;

    LmrcConfig {
        project: ProjectConfig {
            name: "project".to_string(),
            description: "Project".to_string(),
        },
        providers: ProviderConfig {
            server: "hetzner".to_string(),
            kubernetes: "k3s".to_string(),
            database: "postgres".to_string(),
            queue: "rabbitmq".to_string(),
            dns: "cloudflare".to_string(),
            git: "gitlab".to_string(),
        },
        apps: AppsConfig {
            applications: vec![],
        },
        infrastructure: InfrastructureConfig {
            provider: "hetzner".to_string(),
            network: None,
            servers: vec![],
            load_balancer: None,
            k3s: None,
            postgres: None,
            rabbitmq: None,
            vault: None,
            dns: None,
            gitlab: None,
        },
    }
}

/// Bundle ready-to-use infrastructure apps (no templating)
fn bundle_infrastructure_apps(project_path: &Path) -> Result<()> {
    println!("  {} Infrastructure apps...", "Bundling:".cyan());

    // Bundle gateway
    let gateway_path = project_path.join("apps").join("gateway");
    copy_app_as_is(&GATEWAY_APP, &gateway_path)?;
    println!("    {} apps/gateway", "✓".green());

    // Bundle infra-api
    let infra_api_path = project_path.join("apps").join("infra-api");
    copy_app_as_is(&INFRA_API_APP, &infra_api_path)?;
    println!("    {} apps/infra-api", "✓".green());

    // Bundle infra-migrator
    let infra_migrator_path = project_path.join("apps").join("infra-migrator");
    copy_app_as_is(&INFRA_MIGRATOR_APP, &infra_migrator_path)?;
    println!("    {} apps/infra-migrator", "✓".green());

    // Bundle app-migrator
    let app_migrator_path = project_path.join("apps").join("app-migrator");
    copy_app_as_is(&APP_MIGRATOR_APP, &app_migrator_path)?;
    println!("    {} apps/app-migrator", "✓".green());

    // Bundle infra-front
    let infra_front_path = project_path.join("apps").join("infra-front");
    copy_app_as_is(&INFRA_FRONT_APP, &infra_front_path)?;
    println!("    {} apps/infra-front", "✓".green());

    Ok(())
}

/// Copy an app directory as-is without any template processing
fn copy_app_as_is(app_dir: &Dir, dest_path: &Path) -> Result<()> {
    fs::create_dir_all(dest_path)?;

    for entry in app_dir.entries() {
        copy_entry_as_is(entry, dest_path)?;
    }

    Ok(())
}

/// Recursively copy directory entries without any processing
/// Renames .template files back to their original names (e.g., Cargo.toml.template -> Cargo.toml)
fn copy_entry_as_is(entry: &include_dir::DirEntry, base_path: &Path) -> Result<()> {
    match entry {
        include_dir::DirEntry::Dir(dir) => {
            let dir_path = base_path.join(dir.path());
            fs::create_dir_all(&dir_path)?;
            for child in dir.entries() {
                copy_entry_as_is(child, base_path)?;
            }
        }
        include_dir::DirEntry::File(file) => {
            let mut file_path = base_path.join(file.path());

            // Rename .template files back to original (e.g., Cargo.toml.template -> Cargo.toml)
            if let Some(path_str) = file_path.to_str() {
                if path_str.ends_with(".template") {
                    file_path = Path::new(&path_str.trim_end_matches(".template")).to_path_buf();
                }
            }

            if let Some(parent) = file_path.parent() {
                fs::create_dir_all(parent)?;
            }
            fs::write(&file_path, file.contents())?;
        }
    }
    Ok(())
}

/// Generate a single application based on its type (internal version with full config)
fn generate_single_app_internal(
    project_path: &Path,
    app: &ApplicationEntry,
    config: &LmrcConfig,
) -> Result<()> {
    let app_path = project_path.join("apps").join(&app.name);
    fs::create_dir_all(&app_path)?;

    match &app.app_type {
        Some(AppType::Gateway) => {
            // Gateway is bundled as infrastructure app - copy it from embedded
            copy_app_as_is(&GATEWAY_APP, &app_path)?;
            println!("  {} apps/{} (API Gateway with auth)", "Created:".green(), app.name);
        }
        Some(AppType::Api) => {
            generate_from_template(&API_SERVICE_TEMPLATE, &app_path, app, config)?;
            println!("  {} apps/{} (API service)", "Created:".green(), app.name);
        }
        Some(AppType::Migrator) => {
            // Migrator is bundled as app-migrator - copy it from embedded
            copy_app_as_is(&APP_MIGRATOR_APP, &app_path)?;
            println!("  {} apps/{} (Database migrator)", "Created:".green(), app.name);
        }
        Some(AppType::Basic) | None => {
            // Fallback to basic app generation
            generate_basic_app(&app_path, app)?;
            println!("  {} apps/{} (basic app)", "Created:".green(), app.name);
        }
    }

    Ok(())
}

/// Generate application from embedded template
fn generate_from_template(
    template: &Dir,
    app_path: &Path,
    app: &ApplicationEntry,
    config: &LmrcConfig,
) -> Result<()> {
    for entry in template.entries() {
        extract_and_process_entry(entry, app_path, app, config)?;
    }
    Ok(())
}

/// Recursively extract and process template entries
fn extract_and_process_entry(
    entry: &include_dir::DirEntry,
    base_path: &Path,
    app: &ApplicationEntry,
    config: &LmrcConfig,
) -> Result<()> {
    match entry {
        include_dir::DirEntry::Dir(dir) => {
            let dir_path = base_path.join(dir.path());
            fs::create_dir_all(&dir_path)?;
            for child in dir.entries() {
                extract_and_process_entry(child, base_path, app, config)?;
            }
        }
        include_dir::DirEntry::File(file) => {
            let mut file_path = base_path.join(file.path());

            // Rename .template files back to original (e.g., Cargo.toml.template -> Cargo.toml)
            if let Some(path_str) = file_path.to_str() {
                if path_str.ends_with(".template") {
                    file_path = Path::new(&path_str.trim_end_matches(".template")).to_path_buf();
                }
            }

            if let Some(parent) = file_path.parent() {
                fs::create_dir_all(parent)?;
            }

            // Get file contents
            let contents = file.contents();

            // Process text files for placeholder replacement
            if let Ok(text) = std::str::from_utf8(contents) {
                let processed = replace_placeholders(text, app, config);
                fs::write(&file_path, processed)?;
            } else {
                // Binary file, write as-is
                fs::write(&file_path, contents)?;
            }
        }
    }
    Ok(())
}

/// Replace template placeholders with actual values
fn replace_placeholders(content: &str, app: &ApplicationEntry, config: &LmrcConfig) -> String {
    let mut result = content.to_string();

    // Replace app-specific placeholders
    result = result.replace("{{app_name}}", &app.name);

    // Replace port - use deployment port if available, otherwise default
    let port = app
        .deployment
        .as_ref()
        .map(|d| d.port.to_string())
        .unwrap_or_else(|| "8080".to_string());
    result = result.replace("{{app_port}}", &port);

    // Replace project-specific placeholders
    result = result.replace("{{project_name}}", &config.project.name);
    result = result.replace("{{project_description}}", &config.project.description);

    result
}

/// Generate a basic application (fallback for unknown types)
fn generate_basic_app(app_path: &Path, app: &ApplicationEntry) -> Result<()> {
    use lmrc_toml_writer::PackageToml;

    // Create Cargo.toml
    let cargo_toml = PackageToml::new(&app.name)
        .version("0.1.0")
        .edition("2021")
        .dependency_inline("tokio", r#"{ version = "1.0", features = ["full"] }"#)
        .build();

    fs::write(app_path.join("Cargo.toml"), cargo_toml)?;

    // Create src directory and main.rs
    let src_dir = app_path.join("src");
    fs::create_dir_all(&src_dir)?;

    let main_rs = format!(
        r#"#[tokio::main]
async fn main() {{
    println!("Hello from {}!");
}}
"#,
        app.name
    );

    fs::write(src_dir.join("main.rs"), main_rs)?;

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;
    use lmrc_config_validator::*;

    #[test]
    fn test_gateway_app_is_embedded() {
        assert!(GATEWAY_APP.get_file("Cargo.toml.template").is_some());
        assert!(GATEWAY_APP.get_file("src/main.rs").is_some());
    }

    #[test]
    fn test_infra_api_app_is_embedded() {
        assert!(INFRA_API_APP.get_file("Cargo.toml.template").is_some());
        assert!(INFRA_API_APP.get_file("src/main.rs").is_some());
    }

    #[test]
    fn test_infra_migrator_app_is_embedded() {
        assert!(INFRA_MIGRATOR_APP.get_file("Cargo.toml.template").is_some());
        assert!(INFRA_MIGRATOR_APP.get_file("src/main.rs").is_some());
    }

    #[test]
    fn test_app_migrator_app_is_embedded() {
        assert!(APP_MIGRATOR_APP.get_file("Cargo.toml.template").is_some());
        assert!(APP_MIGRATOR_APP.get_file("src/main.rs").is_some());
    }

    #[test]
    fn test_api_service_template_is_embedded() {
        assert!(
            API_SERVICE_TEMPLATE
                .get_file("Cargo.toml.template")
                .is_some()
        );
        assert!(API_SERVICE_TEMPLATE.get_file("src/main.rs").is_some());
    }

    #[test]
    fn test_replace_placeholders() {
        let app = ApplicationEntry {
            name: "my-gateway".to_string(),
            app_type: Some(AppType::Gateway),
            docker: None,
            deployment: Some(DeploymentConfig {
                replicas: 1,
                port: 3000,
                cpu_request: None,
                memory_request: None,
                cpu_limit: None,
                memory_limit: None,
                env: vec![],
            }),
        };

        let config = create_test_config();

        let template =
            "name = \"{{app_name}}\"\nport = {{app_port}}\nproject = \"{{project_name}}\"";
        let result = replace_placeholders(template, &app, &config);

        assert!(result.contains("name = \"my-gateway\""));
        assert!(result.contains("port = 3000"));
        assert!(result.contains("project = \"test-project\""));
    }

    #[test]
    fn test_replace_placeholders_with_default_port() {
        let app = ApplicationEntry {
            name: "my-api".to_string(),
            app_type: Some(AppType::Api),
            docker: None,
            deployment: None, // No deployment config = use default port
        };

        let config = create_test_config();

        let template = "PORT={{app_port}}";
        let result = replace_placeholders(template, &app, &config);

        assert!(result.contains("PORT=8080"));
    }

    fn create_test_config() -> LmrcConfig {
        LmrcConfig {
            project: ProjectConfig {
                name: "test-project".to_string(),
                description: "Test project".to_string(),
            },
            providers: ProviderConfig {
                server: "hetzner".to_string(),
                kubernetes: "k3s".to_string(),
                database: "postgres".to_string(),
                queue: "rabbitmq".to_string(),
                dns: "cloudflare".to_string(),
                git: "gitlab".to_string(),
            },
            apps: AppsConfig {
                applications: vec![],
            },
            infrastructure: InfrastructureConfig {
                provider: "hetzner".to_string(),
                network: None,
                servers: vec![],
                k3s: None,
                postgres: None,
                rabbitmq: None,
                vault: None,
                dns: None,
                gitlab: None,
                load_balancer: None,
            },
        }
    }
}