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::IssueReaction;
use crate::service::AppService;
use crate::service::issues::reactions::CreateIssueReactionParams;
use crate::session::Session;

#[derive(Debug, Deserialize, IntoParams)]
pub struct PathParams {
    /// Workspace name (unique identifier)
    pub workspace_name: String,
    /// Issue number (unique within the workspace)
    pub number: i64,
}

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

/// List reactions on an issue
///
/// Returns a paginated list of all emoji reactions on the given issue.
/// Includes reaction content, target type, and user who added each reaction.
/// Requires read access to the issue.
#[utoipa::path(
    get,
    path = "/api/v1/workspaces/{workspace_name}/issues/{number}/reactions",
    tag = "Issues",
    operation_id = "issueListReactions",
    params(PathParams, QueryParams),
    responses(
        (status = 200, description = "Reactions listed successfully. Returns array of reaction objects.", body = ApiResponse<Vec<IssueReaction>>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions to view this issue", body = ApiErrorResponse),
        (status = 404, description = "Issue not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn list_reactions(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    query: web::Query<QueryParams>,
) -> Result<HttpResponse, AppError> {
    let reactions = service
        .issue
        .issue_reactions(
            &session,
            &path.workspace_name,
            path.number,
            query.limit.unwrap_or(50),
            query.offset.unwrap_or(0),
        )
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new(reactions)))
}

/// Add a reaction to an issue
///
/// Adds an emoji reaction to the given issue.
/// Requires read access to the issue.
///
/// Parameters:
/// - content: Reaction content (e.g., "👍", "❤️", "🎉")
/// - target_type: Target type for the reaction (defaults to "Issue")
/// - target_id: Target ID for reactions on specific comments (optional)
///
/// Returns the created reaction.
#[utoipa::path(
    post,
    path = "/api/v1/workspaces/{workspace_name}/issues/{number}/reactions",
    tag = "Issues",
    operation_id = "issueAddReaction",
    params(PathParams),
    request_body(
        content = CreateIssueReactionParams,
        description = "Reaction creation parameters",
        content_type = "application/json"
    ),
    responses(
        (status = 201, description = "Reaction added successfully. Returns the created reaction.", body = ApiResponse<IssueReaction>),
        (status = 400, description = "Invalid parameters: empty content or invalid target type", body = ApiErrorResponse),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Insufficient permissions", body = ApiErrorResponse),
        (status = 404, description = "Issue not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn add_reaction(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<PathParams>,
    params: web::Json<CreateIssueReactionParams>,
) -> Result<HttpResponse, AppError> {
    let reaction = service
        .issue
        .issue_add_reaction(
            &session,
            &path.workspace_name,
            path.number,
            params.into_inner(),
        )
        .await?;
    Ok(HttpResponse::Created().json(ApiResponse::new(reaction)))
}

#[derive(Debug, Deserialize, IntoParams)]
pub struct ReactionPathParams {
    /// Workspace name (unique identifier)
    pub workspace_name: String,
    /// Issue number (unique within the workspace)
    pub number: i64,
    /// Reaction ID (UUID)
    pub reaction_id: uuid::Uuid,
}

/// Remove a reaction from an issue
///
/// Removes a previously added reaction. Only the user who added the reaction can remove it.
/// Requires read access to the issue.
///
/// Returns success message on completion.
#[utoipa::path(
    delete,
    path = "/api/v1/workspaces/{workspace_name}/issues/{number}/reactions/{reaction_id}",
    tag = "Issues",
    operation_id = "issueRemoveReaction",
    params(ReactionPathParams),
    responses(
        (status = 200, description = "Reaction removed successfully.", body = ApiResponse<String>),
        (status = 401, description = "Authentication required or session expired", body = ApiErrorResponse),
        (status = 403, description = "Cannot remove another user's reaction", body = ApiErrorResponse),
        (status = 404, description = "Reaction not found", body = ApiErrorResponse),
        (status = 500, description = "Internal server error", body = ApiErrorResponse),
    ),
    security(
        ("session_cookie" = [])
    )
)]
pub async fn remove_reaction(
    service: web::Data<AppService>,
    session: Session,
    path: web::Path<ReactionPathParams>,
) -> Result<HttpResponse, AppError> {
    service
        .issue
        .issue_remove_reaction(
            &session,
            &path.workspace_name,
            path.number,
            path.reaction_id,
        )
        .await?;
    Ok(HttpResponse::Ok().json(ApiResponse::new("Reaction removed".to_string())))
}