// Copyright (C) 2024-2026 Whiterun LLC
//
// This software is licensed under the GNU Affero General Public License (AGPL), version 3.0 or later.
// A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/agpl-3.0.html

use anyhow::Result;
use log::info;
use sqlx::sqlite::{SqliteConnectOptions, SqliteJournalMode, SqlitePoolOptions};
use sqlx::SqlitePool;
use std::path::Path;
use std::time::Duration;

use super::DB;
use crate::db::bcmr::prepare_tables as bcmr_prepare_tables;
use crate::db::cauldron::config::check_db_version;
use crate::db::cauldron::prepare_tables as cauldron_prepare_tables;
use crate::db::crc20::prepare_tables as crc20_prepare_tables;
use crate::db::oracle::prepare_tables as oracle_prepare_tables;

/// Create read and write database pools for a given database path
async fn create_db_pool(db_path: &str, read_max_size: u32) -> (bool, SqlitePool, SqlitePool) {
    let db_exists = Path::new(db_path).exists();
    info!("Initializing connection to {db_path} (read_slots={read_max_size})");

    let write_opts = SqliteConnectOptions::new()
        .filename(db_path)
        .journal_mode(SqliteJournalMode::Wal)
        .foreign_keys(true)
        .busy_timeout(Duration::from_secs(30))
        .create_if_missing(true);

    let write_pool = SqlitePoolOptions::new()
        .max_connections(2)
        .connect_with(write_opts)
        .await
        .expect("Failed to initialize write database");

    let read_opts = SqliteConnectOptions::new()
        .filename(db_path)
        .journal_mode(SqliteJournalMode::Wal)
        .foreign_keys(true)
        .busy_timeout(Duration::from_secs(30))
        .create_if_missing(false)
        .read_only(true);

    let read_pool = SqlitePoolOptions::new()
        .max_connections(read_max_size)
        .connect_with(read_opts)
        .await
        .expect("Failed to initialize read database");

    (db_exists, write_pool, read_pool)
}

/// Get the database directory path based on network
pub fn get_db_directory(network: &str) -> &'static str {
    if network.to_lowercase() == "chipnet" {
        "chipnet"
    } else {
        "."
    }
}

/// Create network-specific directory if needed
pub fn ensure_db_directory(db_dir: &str) -> Result<()> {
    if db_dir != "." {
        std::fs::create_dir_all(db_dir).map_err(|e| {
            anyhow::anyhow!("Failed to create database directory '{}': {}", db_dir, e)
        })?;
    }
    Ok(())
}

/// Get the full database path for a filename based on the database directory
fn db_path(db_dir: &str, filename: &str) -> String {
    if db_dir == "." {
        filename.to_string()
    } else {
        format!("{}/{}", db_dir, filename)
    }
}

/// Per-database read pool sizes
pub struct ReadSlots {
    pub cauldron: u32,
    pub bcmr: u32,
    pub crc20: u32,
    pub oracle: u32,
}

/// Initialize all databases and return a DB struct
pub async fn initialize_databases(network: &str, read_slots: ReadSlots) -> Result<DB> {
    let db_dir = get_db_directory(network);
    ensure_db_directory(db_dir)?;

    // Initialize cauldron database
    let (db_exists, cauldron_db_write, cauldron_db_read) =
        create_db_pool(&db_path(db_dir, "cauldron.db"), read_slots.cauldron).await;
    if !db_exists {
        cauldron_prepare_tables(&cauldron_db_write).await;
    } else {
        check_db_version(&cauldron_db_read).await?;
    }

    // Initialize BCMR database
    let (db_exists, bcmr_db_write, bcmr_db_read) =
        create_db_pool(&db_path(db_dir, "bcmr.db"), read_slots.bcmr).await;
    if !db_exists {
        bcmr_prepare_tables(&bcmr_db_write).await;
    }

    // Initialize CRC20 database
    let (db_exists, crc20_db_write, crc20_db_read) =
        create_db_pool(&db_path(db_dir, "crc20.db"), read_slots.crc20).await;
    if !db_exists {
        crc20_prepare_tables(&crc20_db_write).await;
    }

    // Initialize oracle database
    let (db_exists, oracle_db_write, oracle_db_read) =
        create_db_pool(&db_path(db_dir, "oracle.db"), read_slots.oracle).await;
    if !db_exists {
        oracle_prepare_tables(&oracle_db_write).await;
    }

    Ok(DB {
        cauldron_w: cauldron_db_write,
        cauldron_r: cauldron_db_read,
        bcmr_w: bcmr_db_write,
        bcmr_r: bcmr_db_read,
        crc20_w: crc20_db_write,
        crc20_r: crc20_db_read,
        oracle_w: oracle_db_write,
        oracle_r: oracle_db_read,
    })
}