use actix_web::{HttpResponse, web};
use serde::Deserialize;
use utoipa::IntoParams;

use crate::api::response::{ApiErrorResponse, ApiResponse};
use crate::error::AppError;
use crate::models::issues::IssueTemplate;
use crate::service::AppService;
use crate::service::issues::templates::{CreateTemplateParams, UpdateTemplateParams};
use crate::session::Session;

#[derive(Debug, Deserialize, IntoParams)]
pub struct PathParams {
    /// Workspace name (unique identifier)
    pub workspace_name: String,
    /// Repository name (unique within the workspace)
    pub repo_name: String,
}

#[derive(Debug, Deserialize, IntoParams)]
pub struct QueryParams {
    /// Maximum number of templates to return (default: 50, max: 100)
    pub limit: Option<i64>,
    /// Number of templates to skip for pagination (default: 0)
    pub offset: Option<i64>,
}

/// List issue templates in a repository
///
/// Returns a paginated list of all active issue templates in the repository.
/// Templates provide pre-filled content for creating new issues.
/// Sorted alphabetically by name.
/// Requires read access to the repository.
#[utoipa::path(
    get,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/issues/templates",
    tag = "Issues",
    operation_id = "issueListTemplates",
    params(PathParams, QueryParams),
    responses(
        (status = 200, description = "Templates listed successfully. Returns array of template objects.", body = ApiResponse<Vec<IssueTemplate>>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions to access this repository", body = ApiErrorResponse),
        (status = 404, description = "Repository or workspace not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn list_templates(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    query: web::Query<QueryParams>,
) -> Result<HttpResponse, AppError> {
    let templates = service
        .issue
        .issue_templates(
            &session,
            &path.workspace_name,
            &path.repo_name,
            query.limit.unwrap_or(50),
            query.offset.unwrap_or(0),
        )
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new(templates)))
}

/// Create an issue template
///
/// Creates a new issue template in the repository.
/// Requires at least Member role in the repository.
///
/// Parameters:
/// - name: Template name (required)
/// - description: Template description (optional)
/// - title_template: Default title for issues (optional, supports placeholders)
/// - body_template: Default body content in markdown (required)
/// - labels: List of label names to auto-apply (optional)
///
/// Returns the created template with metadata.
#[utoipa::path(
    post,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/issues/templates",
    tag = "Issues",
    operation_id = "issueCreateTemplate",
    params(PathParams),
    request_body(
        content = CreateTemplateParams,
        description = "Template creation parameters",
        content_type = "application/json"
    ),
    responses(
        (status = 201, description = "Template created successfully. Returns the newly created template.", body = ApiResponse<IssueTemplate>),
        (status = 400, description = "Invalid parameters: empty name or body template", body = ApiErrorResponse),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions (requires Member role or higher)", body = ApiErrorResponse),
        (status = 404, description = "Repository or workspace not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn create_template(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    params: web::Json<CreateTemplateParams>,
) -> Result<HttpResponse, AppError> {
    let template = service
        .issue
        .issue_create_template(
            &session,
            &path.workspace_name,
            &path.repo_name,
            params.into_inner(),
        )
        .await?;
    Ok(HttpResponse::Created().json(ApiResponse::new(template)))
}

#[derive(Debug, Deserialize, IntoParams)]
pub struct TemplatePathParams {
    /// Workspace name (unique identifier)
    pub workspace_name: String,
    /// Repository name (unique within the workspace)
    pub repo_name: String,
    /// Template ID (UUID)
    pub template_id: uuid::Uuid,
}

/// Update an issue template
///
/// Updates an existing issue template's metadata and content.
/// Requires Admin role in the repository.
///
/// All fields are optional; only provided fields are updated.
/// Returns the updated template.
#[utoipa::path(
    put,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/issues/templates/{template_id}",
    tag = "Issues",
    operation_id = "issueUpdateTemplate",
    params(TemplatePathParams),
    request_body(
        content = UpdateTemplateParams,
        description = "Template update parameters (all fields optional)",
        content_type = "application/json"
    ),
    responses(
        (status = 200, description = "Template updated successfully. Returns the updated template.", body = ApiResponse<IssueTemplate>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions (requires Admin role)", body = ApiErrorResponse),
        (status = 404, description = "Repository, workspace, or template not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn update_template(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<TemplatePathParams>,
    params: web::Json<UpdateTemplateParams>,
) -> Result<HttpResponse, AppError> {
    let template = service
        .issue
        .issue_update_template(
            &session,
            &path.workspace_name,
            &path.repo_name,
            path.template_id,
            params.into_inner(),
        )
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new(template)))
}

/// Delete an issue template
///
/// Permanently removes an issue template from the repository.
/// Requires Admin role in the repository.
///
/// Returns success message on completion.
#[utoipa::path(
    delete,
    path = "/api/v1/workspaces/{workspace_name}/repos/{repo_name}/issues/templates/{template_id}",
    tag = "Issues",
    operation_id = "issueDeleteTemplate",
    params(TemplatePathParams),
    responses(
        (status = 200, description = "Template deleted successfully.", body = ApiResponse<String>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions (requires Admin role)", body = ApiErrorResponse),
        (status = 404, description = "Template not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn delete_template(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<TemplatePathParams>,
) -> Result<HttpResponse, AppError> {
    service
        .issue
        .issue_delete_template(
            &session,
            &path.workspace_name,
            &path.repo_name,
            path.template_id,
        )
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new("Template deleted".to_string())))
}