// Copyright (C) 2024 Riften Labs AS
//
// 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

// db_utils.rs
// Copyright (C) 2024 Riften Labs AS
// AGPL-3.0-or-later

use anyhow::Result;
use rusqlite::{params, Connection};

pub enum CachedSort {
    ScoreDesc,
    ScoreAsc,
    NameAsc,
    NameDesc,
    SymbolAsc,
    SymbolDesc,
    TvlDesc,
    TvlAsc,
    VolumeDesc,
    VolumeAsc,
    Change24hDesc,
    Change24hAsc,
    Change7dDesc,
    Change7dAsc,
    PriceUsdDesc,
    PriceUsdAsc,
    Change24hUsdDesc,
    Change24hUsdAsc,
    Change7dUsdDesc,
    Change7dUsdAsc,
    Apy30dDesc,
    Apy30dAsc,
}

pub fn order_clause(sort: CachedSort) -> &'static str {
    match sort {
        // Best first: rank ascending if set; else score/volume fallback.
        CachedSort::ScoreDesc => {
            "ORDER BY (NULLIF(score_rank,0) IS NULL) ASC, \
                      NULLIF(score_rank,0) ASC, \
                      score DESC, trade_volume DESC, token_id ASC"
        }

        // Worst first: rank descending if set; else score/volume fallback.
        CachedSort::ScoreAsc => {
            "ORDER BY (NULLIF(score_rank,0) IS NULL) ASC, \
                      NULLIF(score_rank,0) DESC, \
                      score ASC,  trade_volume ASC,  token_id ASC"
        }
        CachedSort::TvlDesc => "ORDER BY tvl_sats DESC, token_id ASC",
        CachedSort::TvlAsc => "ORDER BY tvl_sats ASC,  token_id ASC",
        CachedSort::VolumeDesc => "ORDER BY trade_volume DESC, token_id ASC",
        CachedSort::VolumeAsc => "ORDER BY trade_volume ASC,  token_id ASC",

        // NULLS LAST via leading `IS NULL` (false<true)
        CachedSort::NameAsc => {
            "ORDER BY display_name IS NULL,  display_name COLLATE NOCASE ASC,  token_id ASC"
        }
        CachedSort::NameDesc => {
            "ORDER BY display_name IS NULL,  display_name COLLATE NOCASE DESC, token_id ASC"
        }
        CachedSort::SymbolAsc => {
            "ORDER BY display_symbol IS NULL, display_symbol COLLATE NOCASE ASC,  token_id ASC"
        }
        CachedSort::SymbolDesc => {
            "ORDER BY display_symbol IS NULL, display_symbol COLLATE NOCASE DESC, token_id ASC"
        }

        CachedSort::Change24hDesc => {
            "ORDER BY change_24h_bp   IS NULL, change_24h_bp   DESC, token_id ASC"
        }
        CachedSort::Change24hAsc => {
            "ORDER BY change_24h_bp   IS NULL, change_24h_bp   ASC,  token_id ASC"
        }
        CachedSort::Change7dDesc => {
            "ORDER BY change_7d_bp    IS NULL, change_7d_bp    DESC, token_id ASC"
        }
        CachedSort::Change7dAsc => {
            "ORDER BY change_7d_bp    IS NULL, change_7d_bp    ASC,  token_id ASC"
        }

        CachedSort::PriceUsdDesc => "ORDER BY price_now_usd DESC, token_id ASC",
        CachedSort::PriceUsdAsc => "ORDER BY price_now_usd ASC,  token_id ASC",

        CachedSort::Change24hUsdDesc => {
            "ORDER BY change_24h_usd_bp IS NULL, change_24h_usd_bp DESC, token_id ASC"
        }
        CachedSort::Change24hUsdAsc => {
            "ORDER BY change_24h_usd_bp IS NULL, change_24h_usd_bp ASC,  token_id ASC"
        }
        CachedSort::Change7dUsdDesc => {
            "ORDER BY change_7d_usd_bp IS NULL, change_7d_usd_bp DESC, token_id ASC"
        }
        CachedSort::Change7dUsdAsc => {
            "ORDER BY change_7d_usd_bp IS NULL, change_7d_usd_bp ASC,  token_id ASC"
        }

        CachedSort::Apy30dDesc => "ORDER BY apy_30d_bp IS NULL, apy_30d_bp DESC, token_id ASC",
        CachedSort::Apy30dAsc => "ORDER BY apy_30d_bp IS NULL, apy_30d_bp ASC,  token_id ASC",
    }
}

/// Create the *current* index set only (no drops).
pub fn create_cached_token_metrics_indexes(conn: &Connection) -> Result<()> {
    conn.execute_batch(
        r#"
-- Consolidated sort indexes (ASC can be reverse-scanned for DESC; ties may sort in-memory on token_id)

-- Score / Volume tie-break
CREATE INDEX IF NOT EXISTS idx_ctm_score
ON cached_token_metrics(score, trade_volume, token_id);

-- TVL & Volume single-key sorts
CREATE INDEX IF NOT EXISTS idx_ctm_tvl
ON cached_token_metrics(tvl_sats, token_id);

CREATE INDEX IF NOT EXISTS idx_ctm_volume
ON cached_token_metrics(trade_volume, token_id);

-- Price (USD)
CREATE INDEX IF NOT EXISTS idx_ctm_price_usd
ON cached_token_metrics(price_now_usd, token_id);

-- APY 30d
CREATE INDEX IF NOT EXISTS idx_ctm_apy
ON cached_token_metrics(apy_30d_bp, token_id);

-- NULLS LAST expression indexes for text sorts
CREATE INDEX IF NOT EXISTS idx_ctm_name_ord
ON cached_token_metrics((display_name IS NULL),  display_name COLLATE NOCASE,  token_id);

CREATE INDEX IF NOT EXISTS idx_ctm_symbol_ord
ON cached_token_metrics((display_symbol IS NULL), display_symbol COLLATE NOCASE, token_id);

-- % change (BCH)
CREATE INDEX IF NOT EXISTS idx_ctm_ch24_ord
ON cached_token_metrics((change_24h_bp IS NULL), change_24h_bp, token_id);

CREATE INDEX IF NOT EXISTS idx_ctm_ch7d_ord
ON cached_token_metrics((change_7d_bp IS NULL),  change_7d_bp,  token_id);

-- % change (USD)
CREATE INDEX IF NOT EXISTS idx_ctm_ch24_usd_ord
ON cached_token_metrics((change_24h_usd_bp IS NULL), change_24h_usd_bp, token_id);

CREATE INDEX IF NOT EXISTS idx_ctm_ch7d_usd_ord
ON cached_token_metrics((change_7d_usd_bp IS NULL),  change_7d_usd_bp,  token_id);

CREATE INDEX IF NOT EXISTS idx_ctm_score_rank
ON cached_token_metrics(score_rank, token_id);

ANALYZE;
PRAGMA optimize;
"#,
    )?;
    Ok(())
}

/// Indexes that speed up the aggregation path (tx → phe → pool).
pub fn create_aggregation_path_indexes(conn: &Connection) -> Result<()> {
    conn.execute_batch(
        r#"
-- Scan tx in a time window, then join to phe by txid
CREATE INDEX IF NOT EXISTS idx_tx_effective_ts
ON tx(effective_timestamp, txid);

-- Join tx → phe on txid
CREATE INDEX IF NOT EXISTS idx_phe_txid
ON pool_history_entry(txid);

-- Mixed access patterns (pool then txid)
CREATE INDEX IF NOT EXISTS idx_phe_pool_txid
ON pool_history_entry(pool, txid);

-- Time-bounded scans per pool (snapshots/APY)
CREATE INDEX IF NOT EXISTS idx_phe_pool_timestamp
ON pool_history_entry(pool, effective_timestamp);

-- Join phe.pool → pool.creation_utxo (and cover token_id)
CREATE INDEX IF NOT EXISTS idx_pool_creation_utxo
ON pool(creation_utxo, token_id);

-- Convenience for token-centric lookups
CREATE INDEX IF NOT EXISTS idx_pool_token_id
ON pool(token_id, creation_utxo);

ANALYZE;
PRAGMA optimize;
"#,
    )?;
    Ok(())
}

pub fn create_cached_token_metrics_table(conn: &Connection) -> Result<()> {
    conn.execute_batch(
        r#"
CREATE TABLE IF NOT EXISTS cached_token_metrics (
  token_id          TEXT PRIMARY KEY,
  trade_volume      INTEGER NOT NULL DEFAULT 0,
  tvl_sats          INTEGER NOT NULL DEFAULT 0,
  tvl_tokens        INTEGER NOT NULL DEFAULT 0,
  score             INTEGER NOT NULL DEFAULT 0,
  score_rank        INTEGER NOT NULL DEFAULT 0,
  display_name      TEXT,
  display_symbol    TEXT,

  -- BCH (sats-per-human) prices
  price_now         REAL    NOT NULL DEFAULT 0,
  price_24h         REAL,
  price_7d          REAL,
  change_24h_bp     INTEGER,
  change_7d_bp      INTEGER,

  -- USD per human token (from time-matched oracle)
  price_now_usd     REAL    NOT NULL DEFAULT 0,
  price_24h_usd     REAL,
  price_7d_usd      REAL,
  change_24h_usd_bp INTEGER,
  change_7d_usd_bp  INTEGER,

  apy_30d_bp        INTEGER,

  last_trade_ts     INTEGER,
  updated_at        INTEGER NOT NULL
);
"#,
    )?;
    // This could be inserted directly instead but this makes migration easier to add first pool seen
    add_column_if_missing(conn, "cached_token_metrics", "first_pool_ts", "INTEGER")?;
    Ok(())
}

fn add_column_if_missing(conn: &Connection, table: &str, column: &str, decl: &str) -> Result<()> {
    let mut exists = false;
    let mut stmt = conn.prepare(&format!("PRAGMA table_info({table});"))?;
    let mut rows = stmt.query([])?;
    while let Some(row) = rows.next()? {
        let name: String = row.get(1)?; // column name
        if name.eq_ignore_ascii_case(column) {
            exists = true;
            break;
        }
    }
    if !exists {
        conn.execute(
            &format!("ALTER TABLE {table} ADD COLUMN {column} {decl};"),
            [],
        )?;
    }
    Ok(())
}

fn table_has_column(conn: &Connection, table: &str, column: &str) -> Result<bool> {
    let mut stmt = conn.prepare(&format!("PRAGMA table_info({table});"))?;
    let mut rows = stmt.query([])?;
    while let Some(row) = rows.next()? {
        let name: String = row.get(1)?;
        if name.eq_ignore_ascii_case(column) {
            return Ok(true);
        }
    }
    Ok(false)
}

/// First pool info: (creation_utxo, txid, first_ts, first_height)
pub type FirstPoolInfo = (String, String, i64, Option<i64>);

/// Only set `first_pool_ts` when it is currently NULL or 0.
pub fn cache_first_pool_ts_if_empty(conn: &Connection, token_id: &str, ts: i64) -> Result<()> {
    // Ensure a row exists so the update can succeed.
    conn.execute(
        r#"
        INSERT INTO cached_token_metrics (token_id, updated_at)
        VALUES (?1, strftime('%s','now'))
        ON CONFLICT(token_id) DO NOTHING;
        "#,
        params![token_id],
    )?;

    // Accept NULL *or* 0 as “empty/unset”
    conn.execute(
        r#"
        UPDATE cached_token_metrics
        SET first_pool_ts = ?2
        WHERE token_id = ?1 AND (first_pool_ts IS NULL OR first_pool_ts = 0);
        "#,
        params![token_id, ts],
    )?;
    Ok(())
}

/// Returns (creation_utxo, txid, first_ts, first_height) for the first-ever pool of `token_id`.
pub fn db_first_pool_creation_row(
    conn: &Connection,
    token_id: &str,
) -> Result<Option<FirstPoolInfo>> {
    // Prefer height when available; otherwise fall back to timestamp-only ordering.
    let has_height = table_has_column(conn, "tx", "block_height")?;
    let sql = if has_height {
        r#"
        SELECT p.creation_utxo, uf.txid, t.effective_timestamp, t.block_height
        FROM pool AS p
        JOIN utxo_funding AS uf ON uf.new_utxo_hash = p.creation_utxo
        JOIN tx            AS t  ON t.txid = uf.txid
        WHERE p.token_id = ?
        ORDER BY
            (t.block_height IS NULL) ASC,
            t.block_height ASC,
            t.effective_timestamp ASC,
            uf.txid ASC,
            p.creation_utxo ASC
        LIMIT 1;
        "#
    } else {
        r#"
        SELECT p.creation_utxo, uf.txid, t.effective_timestamp, NULL AS block_height
        FROM pool AS p
        JOIN utxo_funding AS uf ON uf.new_utxo_hash = p.creation_utxo
        JOIN tx            AS t  ON t.txid = uf.txid
        WHERE p.token_id = ?
        ORDER BY
            t.effective_timestamp ASC,
            uf.txid ASC,
            p.creation_utxo ASC
        LIMIT 1;
        "#
    };

    let mut stmt = conn.prepare(sql)?;
    let mut rows = stmt.query(params![token_id])?;
    if let Some(row) = rows.next()? {
        let creation_utxo: String = row.get(0)?;
        let txid: String = row.get(1)?;
        let ts: i64 = row.get(2)?;
        let height: Option<i64> = row.get(3)?;
        Ok(Some((creation_utxo, txid, ts, height)))
    } else {
        Ok(None)
    }
}