use crate::state::AppState;
use axum::{
    Json,
    extract::State,
    http::StatusCode,
    response::{IntoResponse, Response},
};
use chrono::{Duration, Utc};
use serde::{Deserialize, Serialize};
use serde_json::json;
use tracing::{error, info, warn};
use uuid::Uuid;

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct CheckAccountStatusOutput {
    pub activated: bool,
    pub valid_did: bool,
    pub repo_commit: String,
    pub repo_rev: String,
    pub repo_blocks: i64,
    pub indexed_records: i64,
    pub private_state_values: i64,
    pub expected_blobs: i64,
    pub imported_blobs: i64,
}

pub async fn check_account_status(
    State(state): State<AppState>,
    headers: axum::http::HeaderMap,
) -> Response {
    let auth_header = headers.get("Authorization");
    if auth_header.is_none() {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationRequired"})),
        )
            .into_response();
    }

    let token = auth_header
        .unwrap()
        .to_str()
        .unwrap_or("")
        .replace("Bearer ", "");

    let session = sqlx::query!(
        r#"
        SELECT s.did, k.key_bytes, u.id as user_id
        FROM sessions s
        JOIN users u ON s.did = u.did
        JOIN user_keys k ON u.id = k.user_id
        WHERE s.access_jwt = $1
        "#,
        token
    )
    .fetch_optional(&state.db)
    .await;

    let (did, key_bytes, user_id) = match session {
        Ok(Some(row)) => (row.did, row.key_bytes, row.user_id),
        Ok(None) => {
            return (
                StatusCode::UNAUTHORIZED,
                Json(json!({"error": "AuthenticationFailed"})),
            )
                .into_response();
        }
        Err(e) => {
            error!("DB error in check_account_status: {:?}", e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response();
        }
    };

    if let Err(_) = crate::auth::verify_token(&token, &key_bytes) {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationFailed", "message": "Invalid token signature"})),
        )
            .into_response();
    }

    let user_status = sqlx::query!("SELECT deactivated_at FROM users WHERE did = $1", did)
        .fetch_optional(&state.db)
        .await;

    let deactivated_at = match user_status {
        Ok(Some(row)) => row.deactivated_at,
        _ => None,
    };

    let repo_result = sqlx::query!("SELECT repo_root_cid FROM repos WHERE user_id = $1", user_id)
        .fetch_optional(&state.db)
        .await;

    let repo_commit = match repo_result {
        Ok(Some(row)) => row.repo_root_cid,
        _ => String::new(),
    };

    let record_count: i64 = sqlx::query_scalar!("SELECT COUNT(*) FROM records WHERE repo_id = $1", user_id)
        .fetch_one(&state.db)
        .await
        .unwrap_or(Some(0))
        .unwrap_or(0);

    let blob_count: i64 =
        sqlx::query_scalar!("SELECT COUNT(*) FROM blobs WHERE created_by_user = $1", user_id)
            .fetch_one(&state.db)
            .await
            .unwrap_or(Some(0))
            .unwrap_or(0);

    let valid_did = did.starts_with("did:");

    (
        StatusCode::OK,
        Json(CheckAccountStatusOutput {
            activated: deactivated_at.is_none(),
            valid_did,
            repo_commit: repo_commit.clone(),
            repo_rev: chrono::Utc::now().timestamp_millis().to_string(),
            repo_blocks: 0,
            indexed_records: record_count,
            private_state_values: 0,
            expected_blobs: blob_count,
            imported_blobs: blob_count,
        }),
    )
        .into_response()
}

pub async fn activate_account(
    State(state): State<AppState>,
    headers: axum::http::HeaderMap,
) -> Response {
    let auth_header = headers.get("Authorization");
    if auth_header.is_none() {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationRequired"})),
        )
            .into_response();
    }

    let token = auth_header
        .unwrap()
        .to_str()
        .unwrap_or("")
        .replace("Bearer ", "");

    let session = sqlx::query!(
        r#"
        SELECT s.did, k.key_bytes
        FROM sessions s
        JOIN users u ON s.did = u.did
        JOIN user_keys k ON u.id = k.user_id
        WHERE s.access_jwt = $1
        "#,
        token
    )
    .fetch_optional(&state.db)
    .await;

    let (did, key_bytes) = match session {
        Ok(Some(row)) => (row.did, row.key_bytes),
        Ok(None) => {
            return (
                StatusCode::UNAUTHORIZED,
                Json(json!({"error": "AuthenticationFailed"})),
            )
                .into_response();
        }
        Err(e) => {
            error!("DB error in activate_account: {:?}", e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response();
        }
    };

    if let Err(_) = crate::auth::verify_token(&token, &key_bytes) {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationFailed", "message": "Invalid token signature"})),
        )
            .into_response();
    }

    let result = sqlx::query!("UPDATE users SET deactivated_at = NULL WHERE did = $1", did)
        .execute(&state.db)
        .await;

    match result {
        Ok(_) => (StatusCode::OK, Json(json!({}))).into_response(),
        Err(e) => {
            error!("DB error activating account: {:?}", e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response()
        }
    }
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct DeactivateAccountInput {
    pub delete_after: Option<String>,
}

pub async fn deactivate_account(
    State(state): State<AppState>,
    headers: axum::http::HeaderMap,
    Json(_input): Json<DeactivateAccountInput>,
) -> Response {
    let auth_header = headers.get("Authorization");
    if auth_header.is_none() {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationRequired"})),
        )
            .into_response();
    }

    let token = auth_header
        .unwrap()
        .to_str()
        .unwrap_or("")
        .replace("Bearer ", "");

    let session = sqlx::query!(
        r#"
        SELECT s.did, k.key_bytes
        FROM sessions s
        JOIN users u ON s.did = u.did
        JOIN user_keys k ON u.id = k.user_id
        WHERE s.access_jwt = $1
        "#,
        token
    )
    .fetch_optional(&state.db)
    .await;

    let (did, key_bytes) = match session {
        Ok(Some(row)) => (row.did, row.key_bytes),
        Ok(None) => {
            return (
                StatusCode::UNAUTHORIZED,
                Json(json!({"error": "AuthenticationFailed"})),
            )
                .into_response();
        }
        Err(e) => {
            error!("DB error in deactivate_account: {:?}", e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response();
        }
    };

    if let Err(_) = crate::auth::verify_token(&token, &key_bytes) {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationFailed", "message": "Invalid token signature"})),
        )
            .into_response();
    }

    let result = sqlx::query!("UPDATE users SET deactivated_at = NOW() WHERE did = $1", did)
        .execute(&state.db)
        .await;

    match result {
        Ok(_) => (StatusCode::OK, Json(json!({}))).into_response(),
        Err(e) => {
            error!("DB error deactivating account: {:?}", e);
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response()
        }
    }
}

pub async fn request_account_delete(
    State(state): State<AppState>,
    headers: axum::http::HeaderMap,
) -> Response {
    let auth_header = headers.get("Authorization");
    if auth_header.is_none() {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationRequired"})),
        )
            .into_response();
    }

    let token = auth_header
        .unwrap()
        .to_str()
        .unwrap_or("")
        .replace("Bearer ", "");

    let session = sqlx::query!(
        r#"
        SELECT s.did, u.id as user_id, u.email, u.handle, k.key_bytes
        FROM sessions s
        JOIN users u ON s.did = u.did
        JOIN user_keys k ON u.id = k.user_id
        WHERE s.access_jwt = $1
        "#,
        token
    )
    .fetch_optional(&state.db)
    .await;

    let (did, user_id, email, handle, key_bytes) = match session {
        Ok(Some(row)) => (row.did, row.user_id, row.email, row.handle, row.key_bytes),
        Ok(None) => {
            return (
                StatusCode::UNAUTHORIZED,
                Json(json!({"error": "AuthenticationFailed"})),
            )
                .into_response();
        }
        Err(e) => {
            error!("DB error in request_account_delete: {:?}", e);
            return (
                StatusCode::INTERNAL_SERVER_ERROR,
                Json(json!({"error": "InternalError"})),
            )
                .into_response();
        }
    };

    if let Err(_) = crate::auth::verify_token(&token, &key_bytes) {
        return (
            StatusCode::UNAUTHORIZED,
            Json(json!({"error": "AuthenticationFailed", "message": "Invalid token signature"})),
        )
            .into_response();
    }

    let confirmation_token = Uuid::new_v4().to_string();
    let expires_at = Utc::now() + Duration::minutes(15);

    let insert = sqlx::query!(
        "INSERT INTO account_deletion_requests (token, did, expires_at) VALUES ($1, $2, $3)",
        confirmation_token,
        did,
        expires_at
    )
    .execute(&state.db)
    .await;

    if let Err(e) = insert {
        error!("DB error creating deletion token: {:?}", e);
        return (
            StatusCode::INTERNAL_SERVER_ERROR,
            Json(json!({"error": "InternalError"})),
        )
            .into_response();
    }

    let hostname = std::env::var("PDS_HOSTNAME").unwrap_or_else(|_| "localhost".to_string());
    if let Err(e) = crate::notifications::enqueue_account_deletion(
        &state.db,
        user_id,
        &email,
        &handle,
        &confirmation_token,
        &hostname,
    )
    .await
    {
        warn!("Failed to enqueue account deletion notification: {:?}", e);
    }

    info!("Account deletion requested for user {}", did);

    (StatusCode::OK, Json(json!({}))).into_response()
}