use axum::{
    extract::State,
    Json,
    response::{IntoResponse, Response},
    http::StatusCode,
};
use serde::{Deserialize, Serialize};
use serde_json::json;
use crate::state::AppState;
use chrono::Utc;
use sqlx::Row;
use cid::Cid;
use std::str::FromStr;
use jacquard_repo::{mst::Mst, commit::Commit, storage::BlockStore};
use jacquard::types::{string::{Nsid, Tid}, did::Did, integer::LimitedU32};
use tracing::error;
use std::sync::Arc;

#[derive(Deserialize)]
#[allow(dead_code)]
pub struct CreateRecordInput {
    pub repo: String,
    pub collection: String,
    pub rkey: Option<String>,
    pub validate: Option<bool>,
    pub record: serde_json::Value,
    #[serde(rename = "swapCommit")]
    pub swap_commit: Option<String>,
}

#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct CreateRecordOutput {
    pub uri: String,
    pub cid: String,
}

pub async fn create_record(
    State(state): State<AppState>,
    headers: axum::http::HeaderMap,
    Json(input): Json<CreateRecordInput>,
) -> 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 ", "");

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

    let session = sqlx::query("SELECT did FROM sessions WHERE access_jwt = $1")
        .bind(&token)
        .fetch_optional(&state.db)
        .await
        .unwrap_or(None);

    let did = match session {
        Some(row) => row.get::<String, _>("did"),
        None => return (StatusCode::UNAUTHORIZED, Json(json!({"error": "AuthenticationFailed"}))).into_response(),
    };

    if input.repo != did {
        return (StatusCode::FORBIDDEN, Json(json!({"error": "InvalidRepo", "message": "Repo does not match authenticated user"}))).into_response();
    }

    let user_query = sqlx::query("SELECT id FROM users WHERE did = $1")
        .bind(&did)
        .fetch_optional(&state.db)
        .await;

    let user_id: uuid::Uuid = match user_query {
        Ok(Some(row)) => row.get("id"),
        _ => return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError", "message": "User not found"}))).into_response(),
    };

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

    let current_root_cid = match repo_root_query {
        Ok(Some(row)) => {
            let cid_str: String = row.get("repo_root_cid");
            Cid::from_str(&cid_str).ok()
        },
        _ => None,
    };

    if current_root_cid.is_none() {
         error!("Repo root not found for user {}", did);
         return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError", "message": "Repo root not found"}))).into_response();
    }
    let current_root_cid = current_root_cid.unwrap();

    let commit_bytes = match state.block_store.get(&current_root_cid).await {
        Ok(Some(b)) => b,
        Ok(None) => {
             error!("Commit block not found: {}", current_root_cid);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        },
        Err(e) => {
             error!("Failed to load commit block: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let commit = match Commit::from_cbor(&commit_bytes) {
        Ok(c) => c,
        Err(e) => {
             error!("Failed to parse commit: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let mst_root = commit.data;
    let store = Arc::new(state.block_store.clone());
    let mst = Mst::load(store.clone(), mst_root, None);

    let collection_nsid = match input.collection.parse::<Nsid>() {
        Ok(n) => n,
        Err(_) => return (StatusCode::BAD_REQUEST, Json(json!({"error": "InvalidCollection"}))).into_response(),
    };

    let rkey = input.rkey.unwrap_or_else(|| {
        Utc::now().format("%Y%m%d%H%M%S%f").to_string()
    });

    let mut record_bytes = Vec::new();
    if let Err(e) = serde_ipld_dagcbor::to_writer(&mut record_bytes, &input.record) {
        error!("Error serializing record: {:?}", e);
        return (StatusCode::BAD_REQUEST, Json(json!({"error": "InvalidRecord", "message": "Failed to serialize record"}))).into_response();
    }

    let record_cid = match state.block_store.put(&record_bytes).await {
        Ok(c) => c,
        Err(e) => {
             error!("Failed to save record block: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let key = format!("{}/{}", collection_nsid, rkey);
    if let Err(e) = mst.update(&key, record_cid).await {
         error!("Failed to update MST: {:?}", e);
         return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
    }

    let new_mst_root = match mst.root().await {
        Ok(c) => c,
        Err(e) => {
             error!("Failed to get new MST root: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let did_obj = match Did::new(&did) {
        Ok(d) => d,
        Err(_) => return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError", "message": "Invalid DID"}))).into_response(),
    };

    let rev = Tid::now(LimitedU32::MIN);

    let new_commit = Commit::new_unsigned(
        did_obj,
        new_mst_root,
        rev,
        Some(current_root_cid)
    );

    let new_commit_bytes = match new_commit.to_cbor() {
        Ok(b) => b,
        Err(e) => {
             error!("Failed to serialize new commit: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let new_root_cid = match state.block_store.put(&new_commit_bytes).await {
        Ok(c) => c,
        Err(e) => {
             error!("Failed to save new commit: {:?}", e);
             return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
        }
    };

    let update_repo = sqlx::query("UPDATE repos SET repo_root_cid = $1 WHERE user_id = $2")
        .bind(new_root_cid.to_string())
        .bind(user_id)
        .execute(&state.db)
        .await;

    if let Err(e) = update_repo {
        error!("Failed to update repo root in DB: {:?}", e);
        return (StatusCode::INTERNAL_SERVER_ERROR, Json(json!({"error": "InternalError"}))).into_response();
    }

    let record_insert = sqlx::query(
        "INSERT INTO records (repo_id, collection, rkey, record_cid) VALUES ($1, $2, $3, $4)
         ON CONFLICT (repo_id, collection, rkey) DO UPDATE SET record_cid = $4, created_at = NOW()"
    )
        .bind(user_id)
        .bind(&input.collection)
        .bind(&rkey)
        .bind(record_cid.to_string())
        .execute(&state.db)
        .await;

    if let Err(e) = record_insert {
        error!("Error inserting record index: {:?}", e);
    }

    let output = CreateRecordOutput {
        uri: format!("at://{}/{}/{}", input.repo, input.collection, rkey),
        cid: record_cid.to_string(),
    };
    (StatusCode::OK, Json(output)).into_response()
}