use rusqlite::{Connection, params};

#[derive(Clone, Debug)]
pub struct Word {
    pub key: String,
    pub description: String,
    pub lang: String,
}

pub struct FileDatabase {
    connection: Connection,
}

impl FileDatabase {
    pub fn new(path: &str) -> Result<Self, String> {
        let connection_result = Connection::open(path);
        match connection_result {
            Ok(connection) => {
                let file_database = Self {
                    connection: connection,
                };
                file_database.init();
                return Ok(file_database);
            }
            Err(error) => {
                if let Some(error_code) = error.sqlite_error_code() {
                    return Err(format!("{:?}", error_code));
                }
            }
        }

        return Err(format!("Error while accessing the database file."));
    }

    fn init(&self) {
        self.connection
            .execute(
                "CREATE TABLE IF NOT EXISTS word (
                key TEXT PRIMARY KEY,
                description  TEXT NOT NULL,
                lang VARCHAR(2) NOT NULL
            )",
                (), // empty list of parameters.
            )
            .unwrap();
    }
}

pub trait WordSource {
    fn get_all_words(&self) -> Vec<Word>;
    fn find_by_word(&self, word: &str) -> Vec<Word>;
    fn find_by_lang(&self, lang: &str) -> Vec<Word>;
    fn find_by_word_and_lang(&self, word: &str, lang: &str) -> Vec<Word>;
    fn insert_word(&self, word: Word) -> Result<(), ()>;
    fn remove_word(&self, word_key: &str) -> Result<(), ()>;
    fn edit_word(&self, word: Word, key: &str) -> Result<Word, ()>;
    fn normalize_word_key(word_key: &str) -> String;
    fn normalize_lang_key(word_key: &str) -> String;
}

// TODO: improve fuzzy
fn fuzzy_compare(a: &str, b: &str) -> bool {
    if a.eq(b) || a.contains(b) || b.contains(a) {
        return true;
    }
    false
}

impl WordSource for FileDatabase {
    fn get_all_words(&self) -> Vec<Word> {
        let statement = self
            .connection
            .prepare("select key, description, lang from word ORDER BY key ASC");
        let mut word_list: Vec<Word> = vec![];

        // TODO: make this pretty with functional programming
        if let Ok(mut query) = statement {
            let mut rows = query.query([]).unwrap();
            while let Some(row) = rows.next().unwrap() {
                let found_word: String = row.get(0).unwrap();
                let found_word_description: String = row.get(1).unwrap();
                let found_word_lang: String = row.get(2).unwrap();
                word_list.push(Word {
                    key: found_word,
                    description: found_word_description,
                    lang: found_word_lang,
                });
            }
        }

        word_list
    }

    fn find_by_word(&self, word: &str) -> Vec<Word> {
        let statement = self
            .connection
            .prepare("SELECT key, description, lang FROM word ORDER BY key ASC");
        let mut word_list: Vec<Word> = vec![];

        if let Ok(mut query) = statement {
            let mut rows = query.query([]).unwrap();
            while let Some(row) = rows.next().unwrap() {
                let found_word: String = row.get(0).unwrap();
                if fuzzy_compare(word, &found_word) {
                    let found_word_description: String = row.get(1).unwrap();
                    let found_word_lang: String = row.get(2).unwrap();
                    word_list.push(Word {
                        key: found_word,
                        description: found_word_description,
                        lang: found_word_lang,
                    });
                }
            }
        }
        word_list
    }

    fn find_by_lang(&self, lang: &str) -> Vec<Word> {
        let statement = self
            .connection
            .prepare("select key, description, lang from word where lang = ?1 ORDER BY key ASC");
        let mut word_list: Vec<Word> = vec![];

        // TODO: make this pretty with functional programming
        if let Ok(mut query) = statement {
            let mut rows = query.query([lang]).unwrap();
            while let Some(row) = rows.next().unwrap() {
                let found_word: String = row.get(0).unwrap();
                let found_word_description: String = row.get(1).unwrap();
                let found_word_lang: String = row.get(2).unwrap();
                word_list.push(Word {
                    key: found_word,
                    description: found_word_description,
                    lang: found_word_lang,
                });
            }
        }

        word_list
    }

    fn find_by_word_and_lang(&self, word: &str, lang: &str) -> Vec<Word> {
        let statement = self
            .connection
            .prepare("SELECT key, description, lang FROM word where lang = ?1 ORDER BY key ASC");
        let mut word_list: Vec<Word> = vec![];

        if let Ok(mut query) = statement {
            let mut rows = query.query([lang]).unwrap();
            while let Some(row) = rows.next().unwrap() {
                let found_word: String = row.get(0).unwrap();
                if fuzzy_compare(word, &found_word) {
                    let found_word_description: String = row.get(1).unwrap();
                    let found_word_lang: String = row.get(2).unwrap();
                    word_list.push(Word {
                        key: found_word,
                        description: found_word_description,
                        lang: found_word_lang,
                    });
                }
            }
        }
        word_list
    }

    fn insert_word(&self, word: Word) -> Result<(), ()> {
        let result = self.connection.execute(
            "INSERT INTO word (key, description, lang) VALUES (?1, ?2, ?3)",
            (
                &Self::normalize_word_key(&word.key),
                &word.description,
                &Self::normalize_lang_key(&word.lang),
            ),
        );
        if let Ok(count) = result {
            if count > 0 {
                return Ok(());
            }
        }
        Err(())
    }

    fn edit_word(&self, word: Word, key: &str) -> Result<Word, ()> {
        let result = self.connection.execute(
            "UPDATE word SET key = ?1, description = ?2, lang = ?3 WHERE key = ?4",
            (
                &Self::normalize_word_key(&word.key),
                &word.description,
                &Self::normalize_lang_key(&word.lang),
                key,
            ),
        );
        match result {
            Ok(_) => {
                return Ok(word);
            }
            Err(_) => return Err(()),
        }
    }

    fn remove_word(&self, word_key: &str) -> Result<(), ()> {
        let result = self.connection.execute(
            "DELETE FROM word WHERE key = ?1",
            params![Self::normalize_word_key(word_key)],
        );
        match result {
            Ok(response) => {
                if response > 0 {
                    return Ok(());
                } else {
                    return Err(());
                }
            }
            Err(_) => return Err(()),
        }
    }

    fn normalize_word_key(word_key: &str) -> String {
        // TODO: real normalization, not just lowercase, but keep in mind it must be kept as the
        // final and real word -> Maybe full refactor to include a word id
        word_key.to_lowercase().to_string()
    }

    fn normalize_lang_key(word_key: &str) -> String {
        // TODO: real normalization, not just lowercase, but keep in mind it must be kept as the
        // final and real word -> Maybe full refactor to include a word id
        word_key.to_lowercase().to_string()
    }
}