//! Custom link API: create, update, delete, reorder.

use axum::{
    extract::{Path, State},
    http::{header::HeaderMap, StatusCode},
    response::{Html, IntoResponse, Response},
    Form, Json,
};
use serde::{Deserialize, Serialize};

use crate::{
    auth::AuthUser,
    db::{self, CustomLinkId},
    error::{AppError, Result},
    helpers::{htmx_toast_response, is_htmx_request},
    templates::LinkRowTemplate,
    validation,
    AppState,
};

// =============================================================================
// Custom Links API
// =============================================================================

/// Form input for creating a custom profile link.
#[derive(Debug, Deserialize)]
pub struct CreateLinkRequest {
    pub url: String,
    pub title: String,
    pub description: Option<String>,
}

/// JSON response representing a custom profile link.
#[derive(Debug, Serialize)]
pub struct LinkResponse {
    pub id: CustomLinkId,
    pub url: String,
    pub title: String,
    pub description: Option<String>,
    pub sort_order: i32,
}

/// Create a new custom profile link for the authenticated user.
#[tracing::instrument(skip_all, name = "links::create_link")]
pub(super) async fn create_link(
    State(state): State<AppState>,
    headers: HeaderMap,
    AuthUser(user): AuthUser,
    Form(req): Form<CreateLinkRequest>,
) -> Result<Response> {
    user.check_not_suspended()?;
    // Validate input
    validation::validate_link_url(&req.url)?;
    validation::validate_link_title(&req.title)?;

    let link = db::custom_links::create_custom_link(
        &state.db,
        user.id,
        &req.url,
        &req.title,
        req.description.as_deref(),
    )
    .await?;

    if is_htmx_request(&headers) {
        return Ok(Html(LinkRowTemplate {
            id: link.id.to_string(),
            title: link.title,
            url: link.url,
        }.render_string()).into_response());
    }

    Ok(Json(LinkResponse {
        id: link.id,
        url: link.url,
        title: link.title,
        description: link.description,
        sort_order: link.sort_order,
    }).into_response())
}

/// JSON input for updating a custom profile link.
#[derive(Debug, Deserialize)]
pub struct UpdateLinkRequest {
    pub url: Option<String>,
    pub title: Option<String>,
    pub description: Option<String>,
}

/// Update an existing custom profile link owned by the user.
#[tracing::instrument(skip_all, name = "links::update_link")]
pub(super) async fn update_link(
    State(state): State<AppState>,
    AuthUser(user): AuthUser,
    Path(id): Path<CustomLinkId>,
    Json(req): Json<UpdateLinkRequest>,
) -> Result<impl IntoResponse> {
    user.check_not_suspended()?;

    // Validate input (same rules as create_link, but all fields are optional)
    if let Some(ref url) = req.url {
        validation::validate_link_url(url)?;
    }
    if let Some(ref title) = req.title {
        validation::validate_link_title(title)?;
    }

    // Verify ownership with efficient single-row check
    if !db::custom_links::user_owns_custom_link(&state.db, user.id, id).await? {
        return Err(AppError::NotFound);
    }

    let link = db::custom_links::update_custom_link(
        &state.db,
        id,
        user.id,
        req.url.as_deref(),
        req.title.as_deref(),
        req.description.as_deref(),
    )
    .await?;

    Ok(Json(LinkResponse {
        id: link.id,
        url: link.url,
        title: link.title,
        description: link.description,
        sort_order: link.sort_order,
    }))
}

/// Delete a custom profile link owned by the user.
#[tracing::instrument(skip_all, name = "links::delete_link")]
pub(super) async fn delete_link(
    State(state): State<AppState>,
    headers: HeaderMap,
    AuthUser(user): AuthUser,
    Path(id): Path<CustomLinkId>,
) -> Result<Response> {
    user.check_not_suspended()?;
    // Verify ownership with efficient single-row check
    if !db::custom_links::user_owns_custom_link(&state.db, user.id, id).await? {
        return Err(AppError::NotFound);
    }

    db::custom_links::delete_custom_link(&state.db, id, user.id).await?;

    if is_htmx_request(&headers) {
        return Ok(htmx_toast_response("Link removed", "success").into_response());
    }

    Ok(StatusCode::NO_CONTENT.into_response())
}

/// JSON input for reordering custom profile links.
#[derive(Debug, Deserialize)]
pub struct ReorderLinksRequest {
    pub link_ids: Vec<CustomLinkId>,
}

/// Reorder the authenticated user's custom profile links.
#[tracing::instrument(skip_all, name = "links::reorder_links")]
pub(super) async fn reorder_links(
    State(state): State<AppState>,
    AuthUser(user): AuthUser,
    Json(req): Json<ReorderLinksRequest>,
) -> Result<impl IntoResponse> {
    user.check_not_suspended()?;
    db::custom_links::reorder_custom_links(&state.db, user.id, &req.link_ids).await?;
    Ok(StatusCode::NO_CONTENT)
}