use std::sync::Arc;

#[cfg(feature = "server")]
use axum::{
    extract::{Extension, Path},
    http::StatusCode,
    response::IntoResponse,
    Json,
};
use serde_json::{json, Value};

use super::ApiResponse;
use crate::core::VaultCore;

/// Helper: Try reading with fallback path reconstruction
#[cfg(feature = "server")]
async fn try_fallback_read(
    vault: &Arc<VaultCore>,
    full_path: &str,
) -> Option<axum::response::Response> {
    for (mount_path, _) in vault.engines.iter() {
        let slash = if full_path.starts_with('/') { "" } else { "/" };
        let reconstructed = format!("{}{}{}", mount_path, slash, full_path);

        let (_, relative_path) = vault.split_path(&reconstructed)?;
        let engine = vault.route_to_engine(&reconstructed)?;
        let engine_path = relative_path.trim_start_matches('/');

        if let Ok(Some(data)) = engine.read(engine_path).await {
            let response = ApiResponse::success(data);
            return Some((StatusCode::OK, Json(response)).into_response());
        }
    }
    None
}

/// GET /v1/* - Read a secret from any mounted engine
#[cfg(feature = "server")]
pub async fn read_secret(
    Extension(vault): Extension<Arc<VaultCore>>,
    Path(path): Path<String>,
) -> impl IntoResponse {
    let full_path = path;

    if let Some((_mount_path, relative_path)) = vault.split_path(&full_path) {
        if let Some(engine) = vault.route_to_engine(&full_path) {
            return match engine.read(&relative_path).await {
                Ok(Some(data)) => {
                    let response = ApiResponse::success(data);
                    (StatusCode::OK, Json(response)).into_response()
                }
                Ok(None) => {
                    let response = ApiResponse::<Value>::error("Secret not found");
                    (StatusCode::NOT_FOUND, Json(response)).into_response()
                }
                Err(e) => {
                    let response = ApiResponse::<Value>::error(format!("Failed to read: {}", e));
                    (StatusCode::INTERNAL_SERVER_ERROR, Json(response)).into_response()
                }
            };
        }
        let response = ApiResponse::<Value>::error("No engine mounted at this path");
        return (StatusCode::NOT_FOUND, Json(response)).into_response();
    }

    // Try fallback path reconstruction
    if let Some(response) = try_fallback_read(&vault, &full_path).await {
        return response;
    }

    let response = ApiResponse::<Value>::error("Path not found");
    (StatusCode::NOT_FOUND, Json(response)).into_response()
}

/// Helper: Try writing with fallback path reconstruction
#[cfg(feature = "server")]
async fn try_fallback_write(
    vault: &Arc<VaultCore>,
    full_path: &str,
    payload: &Value,
) -> Option<axum::response::Response> {
    for (mount_path, _) in vault.engines.iter() {
        let slash = if full_path.starts_with('/') { "" } else { "/" };
        let reconstructed = format!("{}{}{}", mount_path, slash, full_path);

        let (_, relative_path) = vault.split_path(&reconstructed)?;
        let engine = vault.route_to_engine(&reconstructed)?;
        let engine_path = relative_path.trim_start_matches('/');

        if engine.write(engine_path, payload).await.is_ok() {
            let response = ApiResponse::success(json!({"path": full_path}));
            return Some((StatusCode::OK, Json(response)).into_response());
        }
    }
    None
}

/// POST /v1/* - Write a secret to any mounted engine
#[cfg(feature = "server")]
pub async fn write_secret(
    Extension(vault): Extension<Arc<VaultCore>>,
    Path(path): Path<String>,
    Json(payload): Json<Value>,
) -> impl IntoResponse {
    let full_path = path;

    if let Some((_mount_path, relative_path)) = vault.split_path(&full_path) {
        if let Some(engine) = vault.route_to_engine(&full_path) {
            return match engine.write(&relative_path, &payload).await {
                Ok(()) => {
                    let response = ApiResponse::success(json!({"path": full_path}));
                    (StatusCode::OK, Json(response)).into_response()
                }
                Err(e) => {
                    let response = ApiResponse::<Value>::error(format!("Failed to write: {}", e));
                    (StatusCode::BAD_REQUEST, Json(response)).into_response()
                }
            };
        }
        let response = ApiResponse::<Value>::error("No engine mounted at this path");
        return (StatusCode::NOT_FOUND, Json(response)).into_response();
    }

    // Try fallback path reconstruction
    if let Some(response) = try_fallback_write(&vault, &full_path, &payload).await {
        return response;
    }

    let response = ApiResponse::<Value>::error("Path not found");
    (StatusCode::NOT_FOUND, Json(response)).into_response()
}

/// PUT /v1/* - Update a secret in any mounted engine
#[cfg(feature = "server")]
pub async fn update_secret(
    Extension(vault): Extension<Arc<VaultCore>>,
    Path(path): Path<String>,
    Json(payload): Json<Value>,
) -> impl IntoResponse {
    let full_path = path;

    match vault.split_path(&full_path) {
        Some((_mount_path, relative_path)) => match vault.route_to_engine(&full_path) {
            Some(engine) => match engine.write(&relative_path, &payload).await {
                Ok(()) => {
                    let response = ApiResponse::success(json!({"path": full_path}));
                    (StatusCode::OK, Json(response)).into_response()
                }
                Err(e) => {
                    let response = ApiResponse::<Value>::error(format!("Failed to update: {}", e));
                    (StatusCode::BAD_REQUEST, Json(response)).into_response()
                }
            },
            None => {
                let response = ApiResponse::<Value>::error("No engine mounted at this path");
                (StatusCode::NOT_FOUND, Json(response)).into_response()
            }
        },
        None => {
            let response = ApiResponse::<Value>::error("Path not found");
            (StatusCode::NOT_FOUND, Json(response)).into_response()
        }
    }
}

/// DELETE /v1/* - Delete a secret from any mounted engine
#[cfg(feature = "server")]
pub async fn delete_secret(
    Extension(vault): Extension<Arc<VaultCore>>,
    Path(path): Path<String>,
) -> impl IntoResponse {
    let full_path = path;

    match vault.split_path(&full_path) {
        Some((_mount_path, relative_path)) => match vault.route_to_engine(&full_path) {
            Some(engine) => match engine.delete(&relative_path).await {
                Ok(()) => {
                    let response: ApiResponse<Value> = ApiResponse::success(json!({}));
                    (StatusCode::NO_CONTENT, Json(response)).into_response()
                }
                Err(e) => {
                    let response = ApiResponse::<Value>::error(format!("Failed to delete: {}", e));
                    (StatusCode::BAD_REQUEST, Json(response)).into_response()
                }
            },
            None => {
                let response = ApiResponse::<Value>::error("No engine mounted at this path");
                (StatusCode::NOT_FOUND, Json(response)).into_response()
            }
        },
        None => {
            let response = ApiResponse::<Value>::error("Path not found");
            (StatusCode::NOT_FOUND, Json(response)).into_response()
        }
    }
}

/// LIST /v1/* - List secrets at a path prefix
#[cfg(feature = "server")]
pub async fn list_secrets(
    Extension(vault): Extension<Arc<VaultCore>>,
    Path(path): Path<String>,
) -> impl IntoResponse {
    let full_path = path;

    match vault.split_path(&full_path) {
        Some((_mount_path, relative_path)) => match vault.route_to_engine(&full_path) {
            Some(engine) => match engine.list(&relative_path).await {
                Ok(items) => {
                    let response = ApiResponse::success(json!({"keys": items}));
                    (StatusCode::OK, Json(response)).into_response()
                }
                Err(e) => {
                    let response = ApiResponse::<Value>::error(format!("Failed to list: {}", e));
                    (StatusCode::BAD_REQUEST, Json(response)).into_response()
                }
            },
            None => {
                let response = ApiResponse::<Value>::error("No engine mounted at this path");
                (StatusCode::NOT_FOUND, Json(response)).into_response()
            }
        },
        None => {
            let response = ApiResponse::<Value>::error("Path not found");
            (StatusCode::NOT_FOUND, Json(response)).into_response()
        }
    }
}