//! Ownership operations: what cards the user has and how many.

use std::collections::HashMap;

use rusqlite::{params, OptionalExtension};

use crate::db::REF_DB;
use crate::error::Result;
use crate::model::{CardRef, ColorSet, LibraryCard};
use crate::Catalog;

/// Map a row shaped `(oracle_id, quantity_owned, location, name, mana_value,
/// colors, color_identity, type_line, image_uri, back_image_uri)` into its
/// library parts. Shared by [`Catalog::list_library`] and the criteria search.
pub(crate) fn row_to_library_parts(
    r: &rusqlite::Row,
) -> rusqlite::Result<(String, i64, String, CardRef)> {
    let oracle_id: String = r.get(0)?;
    Ok((
        oracle_id.clone(),
        r.get::<_, i64>(1)?,
        r.get::<_, String>(2)?,
        CardRef {
            oracle_id,
            name: r.get(3)?,
            mana_value: r.get(4)?,
            colors: ColorSet(r.get::<_, i64>(5)? as u8),
            color_identity: ColorSet(r.get::<_, i64>(6)? as u8),
            type_line: r.get(7)?,
            image_uri: r.get::<_, Option<String>>(8)?.unwrap_or_default(),
            back_image_uri: r.get::<_, Option<String>>(9)?.unwrap_or_default(),
        },
    ))
}

impl Catalog {
    /// Add `delta` copies of a card to the library (increment, creating the row
    /// if needed). `delta` may be negative to decrement; the quantity floors at 0.
    /// Returns the new owned quantity.
    pub fn add_owned(&self, oracle_id: &str, delta: i64) -> Result<i64> {
        let current: i64 = self
            .conn
            .query_row(
                "SELECT quantity_owned FROM library_cards WHERE oracle_id = ?1",
                params![oracle_id],
                |r| r.get(0),
            )
            .optional()?
            .unwrap_or(0);
        self.set_owned(oracle_id, current + delta)
    }

    /// Set the absolute owned quantity for a card (0 removes ownership but keeps
    /// any deck assignments referencing it).
    pub fn set_owned(&self, oracle_id: &str, quantity: i64) -> Result<i64> {
        let q = quantity.max(0);
        self.conn.execute(
            "INSERT INTO library_cards(oracle_id, quantity_owned) VALUES (?1, ?2)
             ON CONFLICT(oracle_id) DO UPDATE SET quantity_owned = excluded.quantity_owned",
            params![oracle_id, q],
        )?;
        Ok(q)
    }

    /// List every owned card (quantity_owned > 0) with deck context, ordered by
    /// name. This is the "browse my library" view without extra criteria.
    pub fn list_library(&self) -> Result<Vec<LibraryCard>> {
        let deck_names = self.deck_names_by_oracle()?;
        let assigned = self.assigned_totals_by_oracle()?;

        let mut stmt = self.conn.prepare(&format!(
            "SELECT lc.oracle_id, lc.quantity_owned, lc.location,
                    oc.name, oc.mana_value, oc.colors, oc.color_identity, oc.type_line, {image}, {back}
             FROM library_cards lc
             JOIN {REF_DB}.oracle_cards oc ON oc.oracle_id = lc.oracle_id
             WHERE lc.quantity_owned > 0
             ORDER BY oc.name COLLATE NOCASE",
            image = crate::db::image_subquery("image_uri"),
            back = crate::db::image_subquery("back_image_uri")
        ))?;
        let rows = stmt
            .query_map([], row_to_library_parts)?
            .collect::<std::result::Result<Vec<_>, _>>()?;

        Ok(rows
            .into_iter()
            .map(|(oid, qty, location, card)| LibraryCard {
                quantity_owned: qty,
                decks: deck_names.get(&oid).cloned().unwrap_or_default(),
                quantity_assigned: *assigned.get(&oid).unwrap_or(&0),
                location,
                card,
            })
            .collect())
    }

    /// Set the free-text storage location for a card (creates the library row if
    /// absent). Empty string clears it.
    pub fn set_location(&self, oracle_id: &str, location: &str) -> Result<()> {
        self.conn.execute(
            "INSERT INTO library_cards(oracle_id, location) VALUES (?1, ?2)
             ON CONFLICT(oracle_id) DO UPDATE SET location = excluded.location",
            params![oracle_id, location],
        )?;
        Ok(())
    }

    /// Map each owned/assigned oracle_id to the deck names it appears in.
    pub(crate) fn deck_names_by_oracle(&self) -> Result<HashMap<String, Vec<String>>> {
        let mut stmt = self.conn.prepare(
            "SELECT dc.oracle_id, d.name
             FROM deck_cards dc JOIN decks d ON d.id = dc.deck_id
             ORDER BY d.name COLLATE NOCASE",
        )?;
        let mut map: HashMap<String, Vec<String>> = HashMap::new();
        let rows = stmt.query_map([], |r| Ok((r.get::<_, String>(0)?, r.get::<_, String>(1)?)))?;
        for row in rows {
            let (oid, name) = row?;
            map.entry(oid).or_default().push(name);
        }
        Ok(map)
    }

    pub(crate) fn assigned_totals_by_oracle(&self) -> Result<HashMap<String, i64>> {
        let mut stmt = self
            .conn
            .prepare("SELECT oracle_id, SUM(quantity) FROM deck_cards GROUP BY oracle_id")?;
        let mut map = HashMap::new();
        let rows = stmt.query_map([], |r| Ok((r.get::<_, String>(0)?, r.get::<_, i64>(1)?)))?;
        for row in rows {
            let (oid, total) = row?;
            map.insert(oid, total);
        }
        Ok(map)
    }
}

#[cfg(test)]
mod tests {
    use crate::test_support;

    #[test]
    fn add_increment_and_floor() {
        let fx = test_support::make();
        let cat = &fx.catalog;

        assert_eq!(cat.add_owned("sol-ring", 1).unwrap(), 1);
        assert_eq!(cat.add_owned("sol-ring", 2).unwrap(), 3);
        assert_eq!(cat.add_owned("sol-ring", -10).unwrap(), 0); // floors at 0
        assert_eq!(cat.set_owned("sol-ring", 4).unwrap(), 4);

        let lib = cat.list_library().unwrap();
        let sol = lib.iter().find(|c| c.card.oracle_id == "sol-ring").unwrap();
        assert_eq!(sol.quantity_owned, 4);
        assert!(sol.decks.is_empty());
        // Image URL is plumbed through from the printings table.
        assert_eq!(sol.card.image_uri, "http://img/sol-ring");
    }

    #[test]
    fn back_image_uri_is_plumbed_through() {
        let fx = test_support::make();
        let cat = &fx.catalog;
        cat.connection()
            .execute(
                "UPDATE ref.printings SET back_image_uri = 'http://img/back' \
                 WHERE oracle_id = 'sol-ring'",
                [],
            )
            .unwrap();
        cat.add_owned("sol-ring", 1).unwrap();

        cat.add_owned("llanowar-elves", 1).unwrap();
        let lib = cat.list_library().unwrap();
        let sol = lib.iter().find(|c| c.card.oracle_id == "sol-ring").unwrap();
        assert_eq!(sol.card.back_image_uri, "http://img/back");

        // Single-faced cards have no back image.
        let elves = lib.iter().find(|c| c.card.oracle_id == "llanowar-elves").unwrap();
        assert_eq!(elves.card.back_image_uri, "");
    }

    #[test]
    fn location_is_stored_and_listed() {
        let fx = test_support::make();
        let cat = &fx.catalog;
        cat.add_owned("sol-ring", 1).unwrap();
        cat.set_location("sol-ring", "Box 1").unwrap();

        let lib = cat.list_library().unwrap();
        let sol = lib.iter().find(|c| c.card.oracle_id == "sol-ring").unwrap();
        assert_eq!(sol.location, "Box 1");

        // Clearing works.
        cat.set_location("sol-ring", "").unwrap();
        let lib = cat.list_library().unwrap();
        let sol = lib.iter().find(|c| c.card.oracle_id == "sol-ring").unwrap();
        assert_eq!(sol.location, "");
    }

    #[test]
    fn list_is_ordered_and_excludes_zero() {
        let fx = test_support::make();
        let cat = &fx.catalog;
        cat.add_owned("serra-angel", 1).unwrap();
        cat.add_owned("lightning-bolt", 1).unwrap();
        cat.set_owned("sol-ring", 0).unwrap();

        let names: Vec<_> = cat
            .list_library()
            .unwrap()
            .into_iter()
            .map(|c| c.card.name)
            .collect();
        assert_eq!(names, vec!["Lightning Bolt", "Serra Angel"]);
    }
}