use crate::data::entities::{WordData, WordGroup};
use crate::notification::NotificationData::{DbLoadError, DbSaveError};
use crate::notification::{MaybeError, NotificationData};
use rusqlite::{Connection, params};
use std::collections::HashMap;

pub fn add_word(word: &mut WordData, connection: &Connection) -> MaybeError {
    let index : u32 = connection
        .query_row(
            "INSERT INTO words (key, value, tags, more, group_id) VALUES (?1, ?2, ?3, ?4, ?5) RETURNING id",
            (
                &word.key,
                &word.value,
                &word.tags,
                serde_json::to_string(&word.additional).unwrap_or_default(),
                &word.group_id,
            ),
            |row| row.get(0),
        ).map_err(|_| DbSaveError)?;

    word.id = index.into();
    Ok(())
}

pub fn add_words(words: &mut [WordData], connection: &mut Connection) -> MaybeError {
    let tx = connection.transaction().map_err(|_| DbLoadError)?;
    let count = words.len();

    {
        let mut stmt = tx
            .prepare(
                "INSERT INTO words (key, value, tags, more, group_id) VALUES (?1, ?2, ?3, ?4, ?5)",
            )
            .expect("Failed to prepare statement");

        for word in words.iter() {
            stmt.execute(params![
                word.key,
                word.value,
                word.tags,
                serde_json::to_string(&word.additional).unwrap_or_default(),
                word.group_id
            ])
            .map_err(|_| DbSaveError)?;
        }
    }

    let last_index: u32 = tx.last_insert_rowid() as u32;
    tx.commit().map_err(|_| DbSaveError)?;

    let start_index = last_index - (count as u32) + 1;

    for (index, id) in (start_index..=last_index).enumerate() {
        words[index].id = id.into();
    }

    Ok(())
}

pub fn update_word(word: &mut WordData, connection: &Connection) -> MaybeError {
    if !word.id.is_valid() {
        Ok(add_word(word, connection)?)
    } else {
        connection
            .execute(
                "UPDATE words SET key = ?1, value = ?2, tags = ?3, more = ?4 WHERE id = ?5",
                (
                    &word.key,
                    &word.value,
                    &word.tags,
                    serde_json::to_string(&word.additional).map_err(|_| DbSaveError)?,
                    &word.id,
                ),
            )
            .map_err(|_| DbSaveError)?;
        Ok(())
    }
}

pub fn delete_word(word: &WordData, connection: &Connection) -> MaybeError {
    if !word.id.is_valid() {
        return Err(DbSaveError);
    }
    connection
        .execute("DELETE FROM words WHERE id = ?1", (&word.id,))
        .map_err(|_| DbSaveError)?;
    Ok(())
}

pub fn load_words(connection: &Connection) -> Result<Vec<WordData>, NotificationData> {
    let mut stmt = connection
        .prepare("SELECT id, key, value, tags, more, group_id FROM words")
        .expect("Failed to prepare statement");
    let word_iter = stmt
        .query_map([], |row| {
            let additional: String = row.get(4)?;
            Ok(WordData {
                id: row.get(0)?,
                key: row.get(1)?,
                value: row.get(2)?,
                tags: row.get(3)?,
                additional: serde_json::from_str::<HashMap<String, String>>(&additional)
                    .unwrap_or_default(),
                group_id: row.get(5)?,
            })
        })
        .map_err(|_| DbLoadError)?;

    let mut buffer = Vec::with_capacity(1024);
    word_iter
        .filter_map(|res| res.ok())
        .for_each(|i| buffer.push(i));

    Ok(buffer)
}

pub fn load_word_groups(connection: &Connection) -> Result<Vec<WordGroup>, NotificationData> {
    let mut stmt = connection
        .prepare("SELECT id, name FROM word_group")
        .expect("Failed to prepare statement");
    let group_iter = stmt
        .query_map([], |row| {
            Ok(WordGroup {
                id: row.get(0)?,
                name: row.get(1)?,
            })
        })
        .map_err(|_| DbLoadError)?;

    let mut buffer = Vec::with_capacity(8);
    group_iter
        .filter_map(|res| res.ok())
        .for_each(|i| buffer.push(i));

    Ok(buffer)
}

pub fn add_group(group: &mut WordGroup, connection: &Connection) -> MaybeError {
    let index: u32 = connection
        .query_row(
            "INSERT INTO word_group (name) VALUES (?1) RETURNING id",
            (&group.name,),
            |row| row.get(0),
        )
        .map_err(|_| DbSaveError)?;

    group.id = index.into();
    Ok(())
}

pub fn update_group(group: &mut WordGroup, connection: &Connection) -> MaybeError {
    if !group.id.is_valid() {
        Ok(add_group(group, connection)?)
    } else {
        connection
            .execute(
                "UPDATE word_group SET name = ?1 WHERE id = ?2",
                (&group.name, &group.id),
            )
            .map_err(|_| DbSaveError)?;
        Ok(())
    }
}

pub fn delete_group(group: &WordGroup, connection: &Connection) -> MaybeError {
    if !group.id.is_valid() {
        return Err(DbSaveError);
    }
    connection
        .execute("DELETE FROM word_group WHERE id = ?1", (&group.id,))
        .map_err(|_| DbSaveError)?;
    Ok(())
}