//! `/api/v1/admin/apps/{id}/secrets*` — secrets admin endpoints
//! (v1.1.7).
//!
//!   * `GET    /apps/{id}/secrets`        — list names + updated_at
//!     (NEVER values).
//!   * `POST   /apps/{id}/secrets`        — set/overwrite a secret.
//!   * `DELETE /apps/{id}/secrets/{name}` — delete a secret.
//!
//! Set/delete are gated by `AppSecretsWrite` (→ `script:write`); list by
//! `AppSecretsRead` (→ `script:read`). The list surface deliberately
//! returns only names + timestamps — the dashboard never receives
//! plaintext. Values are encrypted with the process master key before
//! they touch the database (same envelope as the script `secrets::set`).

use std::sync::Arc;

use axum::extract::{Path, Query, State};
use axum::http::StatusCode;
use axum::response::{IntoResponse, Json, Response};
use axum::routing::get;
use axum::{Extension, Router};
use picloud_shared::{validate_secret_name, AppId, MasterKey, Principal, SecretsError};
use serde::Deserialize;
use serde_json::json;

use crate::app_repo::AppRepository;
use crate::authz::{require, AuthzDenied, AuthzError, AuthzRepo, Capability};
use crate::secrets_repo::{SecretsRepo, SecretsRepoError};
use crate::secrets_service::seal;

#[derive(Clone)]
pub struct SecretsState {
    pub repo: Arc<dyn SecretsRepo>,
    pub apps: Arc<dyn AppRepository>,
    pub authz: Arc<dyn AuthzRepo>,
    pub master_key: MasterKey,
    pub max_value_bytes: usize,
}

pub fn secrets_router(state: SecretsState) -> Router {
    Router::new()
        .route("/apps/{app_id}/secrets", get(list_secrets).post(set_secret))
        .route(
            "/apps/{app_id}/secrets/{name}",
            axum::routing::delete(delete_secret),
        )
        .with_state(state)
}

#[derive(Debug, Deserialize)]
pub struct ListQuery {
    #[serde(default)]
    pub cursor: Option<String>,
    #[serde(default)]
    pub limit: Option<u32>,
}

#[derive(Debug, serde::Serialize)]
struct SecretItem {
    name: String,
    updated_at: chrono::DateTime<chrono::Utc>,
}

#[derive(Debug, serde::Serialize)]
struct ListSecretsResponse {
    secrets: Vec<SecretItem>,
    next_cursor: Option<String>,
}

async fn list_secrets(
    State(s): State<SecretsState>,
    Extension(principal): Extension<Principal>,
    Path(app_id): Path<AppId>,
    Query(q): Query<ListQuery>,
) -> Result<Json<ListSecretsResponse>, SecretsApiError> {
    ensure_app_exists(&*s.apps, app_id).await?;
    require(
        s.authz.as_ref(),
        &principal,
        Capability::AppSecretsRead(app_id),
    )
    .await?;
    let page = s
        .repo
        .list_meta(app_id, q.cursor.as_deref(), q.limit.unwrap_or(0))
        .await?;
    Ok(Json(ListSecretsResponse {
        secrets: page
            .items
            .into_iter()
            .map(|m| SecretItem {
                name: m.name,
                updated_at: m.updated_at,
            })
            .collect(),
        next_cursor: page.next_cursor,
    }))
}

#[derive(Debug, Deserialize)]
pub struct SetSecretRequest {
    pub name: String,
    /// Any JSON value — the dashboard sends a single-line string, but
    /// maps/arrays/numbers round-trip too (matching `secrets::set`).
    pub value: serde_json::Value,
}

async fn set_secret(
    State(s): State<SecretsState>,
    Extension(principal): Extension<Principal>,
    Path(app_id): Path<AppId>,
    Json(input): Json<SetSecretRequest>,
) -> Result<StatusCode, SecretsApiError> {
    ensure_app_exists(&*s.apps, app_id).await?;
    require(
        s.authz.as_ref(),
        &principal,
        Capability::AppSecretsWrite(app_id),
    )
    .await?;
    validate_secret_name(&input.name)?;
    let (ciphertext, nonce) = seal(&s.master_key, &input.value, s.max_value_bytes)?;
    s.repo.set(app_id, &input.name, &ciphertext, &nonce).await?;
    Ok(StatusCode::NO_CONTENT)
}

async fn delete_secret(
    State(s): State<SecretsState>,
    Extension(principal): Extension<Principal>,
    Path((app_id, name)): Path<(AppId, String)>,
) -> Result<StatusCode, SecretsApiError> {
    ensure_app_exists(&*s.apps, app_id).await?;
    require(
        s.authz.as_ref(),
        &principal,
        Capability::AppSecretsWrite(app_id),
    )
    .await?;
    if !s.repo.delete(app_id, &name).await? {
        return Err(SecretsApiError::NotFound);
    }
    Ok(StatusCode::NO_CONTENT)
}

async fn ensure_app_exists(apps: &dyn AppRepository, app_id: AppId) -> Result<(), SecretsApiError> {
    apps.get_by_id(app_id)
        .await
        .map_err(|e| SecretsApiError::Backend(e.to_string()))?
        .ok_or(SecretsApiError::AppNotFound)?;
    Ok(())
}

#[derive(Debug, thiserror::Error)]
pub enum SecretsApiError {
    #[error("app not found")]
    AppNotFound,
    #[error("secret not found")]
    NotFound,
    #[error("invalid request: {0}")]
    Invalid(String),
    #[error("forbidden")]
    Forbidden,
    #[error("authorization repo error: {0}")]
    AuthzRepo(String),
    #[error("secrets backend: {0}")]
    Backend(String),
}

impl From<AuthzDenied> for SecretsApiError {
    fn from(d: AuthzDenied) -> Self {
        match d {
            AuthzDenied::Denied => Self::Forbidden,
            AuthzDenied::Repo(e) => Self::AuthzRepo(e.to_string()),
        }
    }
}

impl From<AuthzError> for SecretsApiError {
    fn from(e: AuthzError) -> Self {
        Self::AuthzRepo(e.to_string())
    }
}

impl From<SecretsRepoError> for SecretsApiError {
    fn from(e: SecretsRepoError) -> Self {
        match e {
            SecretsRepoError::InvalidCursor => Self::Invalid("invalid pagination cursor".into()),
            SecretsRepoError::Db(e) => Self::Backend(e.to_string()),
        }
    }
}

impl From<SecretsError> for SecretsApiError {
    fn from(e: SecretsError) -> Self {
        match e {
            SecretsError::InvalidName(m) => Self::Invalid(m),
            SecretsError::TooLarge { .. } => Self::Invalid(e.to_string()),
            SecretsError::Forbidden => Self::Forbidden,
            other => Self::Backend(other.to_string()),
        }
    }
}

impl IntoResponse for SecretsApiError {
    fn into_response(self) -> Response {
        let (status, body) = match &self {
            Self::AppNotFound | Self::NotFound => {
                (StatusCode::NOT_FOUND, json!({ "error": self.to_string() }))
            }
            Self::Invalid(_) => (
                StatusCode::UNPROCESSABLE_ENTITY,
                json!({ "error": self.to_string() }),
            ),
            Self::Forbidden => (StatusCode::FORBIDDEN, json!({ "error": self.to_string() })),
            Self::AuthzRepo(e) => {
                tracing::error!(error = %e, "secrets admin authz repo error");
                (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    json!({ "error": "internal error" }),
                )
            }
            Self::Backend(e) => {
                tracing::error!(error = %e, "secrets admin backend error");
                (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    json!({ "error": "internal error" }),
                )
            }
        };
        (status, Json(body)).into_response()
    }
}