use std::{path::Path, str::FromStr};

use anyhow::Result;
use rusqlite::{Connection, OptionalExtension, ToSql};

use crate::{
    action::{Action, ActionID, ActionSet, ActionType},
    devices::{DeviceWithName, Devices, DevicesWithName},
};

pub struct DataBase {
    sql: Connection,
}

impl DataBase {
    const VERSION_0_1_0: &'static str = "0.1.0";

    pub async fn new(path: impl AsRef<Path>) -> Result<Self> {
        let me = Self {
            sql: Connection::open(path)?,
        };

        me.generate_tables()?;
        me.init()?;

        Ok(me)
    }

    fn generate_tables(&self) -> Result<()> {
        self.sql.execute(
            "CREATE TABLE IF NOT EXISTS meta (
                id      INTEGER PRIMARY KEY,
                version INTEGER NOT NULL
            )",
            [],
        )?;

        self.sql.execute(
            "CREATE TABLE IF NOT EXISTS devices (
                id      INTEGER PRIMARY KEY,
                device  VARCHAR(60) NOT NULL,
                type    VARCHAR(30) NOT NULL,
                control INTEGER NOT NULL,
                name    VARCHAR(80)
            )",
            [],
        )?;

        self.sql.execute(
            "CREATE TABLE IF NOT EXISTS data (
                id          INTEGER PRIMARY KEY,
                time        BIGINT NOT NULL,
                name        VARCHAR(30) NOT NULL,
                value       REAL NOT NULL,
                device_id   INTEGER NOT NULL,
                FOREIGN KEY(device_id) REFERENCES devices(id)
            )",
            [],
        )?;

        self.sql.execute(
            "CREATE TABLE IF NOT EXISTS credentials (
                id          INTEGER PRIMARY KEY,
                key         VARCHAR(60) NOT NULL,
                device_id   BIGINT NOT NULL,
                cred        VARCHAR(256) NOT NULL
            )",
            [],
        )?;

        self.sql.execute(
            "
            CREATE TABLE IF NOT EXISTS actions (
                id          INTEGER PRIMARY KEY,
                device_id   INTEGER NOT NULL,
                action      VARCHAR(30) NOT NULL,
                parameter   VARCHAR(60) NOT NULL,
                action_id   INTEGER,
                FOREIGN KEY(action_id) REFERENCES actions(id),
                FOREIGN KEY(device_id) REFERENCES devices(id)
            )
            ",
            [],
        )?;

        Ok(())
    }

    fn device_id(&self, device_name: &str) -> Result<i64> {
        Ok(self
            .sql
            .prepare(&format!(
                "
                    SELECT id
                    FROM devices
                    WHERE device=\"{}\"
                ",
                device_name
            ))?
            .query_row([], |row| Ok(row.get(0)?))?)
    }

    pub fn insert_action_set(&self, action_set: ActionSet) -> Result<ActionID> {
        let mut action_ids = Vec::new();

        for (i, action) in action_set.iter().enumerate() {
            // get device id from device name
            let device_id = self.device_id(&action.device_id)?;

            // insert action to DB
            self.sql.execute(
                &format!(
                    "INSERT INTO actions (device_id, action, parameter)
                    VALUES (?1, \"{}\", \"{}\")",
                    action.action_type, action.parameter
                ),
                &[&device_id],
            )?;

            action_ids.push(self.sql.last_insert_rowid());

            if i > 0 {
                // chain actions
                self.sql.execute(
                    &format!(
                        "
                            UPDATE actions
                            SET action_id=?2
                            WHERE id=?1
                        "
                    ),
                    [&action_ids[i - 1], &action_ids[i]],
                )?;
            }
        }

        Ok(ActionID(action_ids[0]))
    }

    pub fn remove_action_set(&self, action_set: &ActionSet) -> Result<()> {
        if let Some(action_id) = action_set.first_id() {
            self.sql.execute(
                "
                        DELETE FROM actions
                        WHERE id=?1
                    ",
                &[&action_id.0],
            )?;
        }

        Ok(())
    }

    pub fn action_set(&self, mut action_id: ActionID) -> Result<ActionSet> {
        let mut action_set = ActionSet::default();

        loop {
            let (device_id, action, parameter, next_action): (i64, String, String, Option<i64>) =
                self.sql.query_row(
                    "
                    SELECT device_id, action, parameter, action_id
                    FROM actions
                    WHERE id=?1
                ",
                    &[&action_id.0],
                    |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?)),
                )?;

            let device_name: String = self.sql.query_row(
                "
                    SELECT device
                    FROM devices
                    WHERE id=?1
                ",
                &[&device_id],
                |row| row.get(0),
            )?;

            let mut action = Action::new(device_name, ActionType::from_str(&action)?, parameter);
            action.id = Some(action_id);

            action_set.chain(action);

            match next_action {
                Some(id) => action_id.0 = id,
                None => break,
            }
        }

        Ok(action_set)
    }

    pub fn action_sets(&self, device_name: &str) -> Result<Vec<ActionSet>> {
        let mut action_sets = Vec::new();

        let device_id = self.device_id(device_name)?;

        let base_actions: Vec<i64> = self
            .sql
            .prepare(
                "
                SELECT id
                FROM actions
                WHERE device_id=?1
            ",
            )?
            .query_map(&[&device_id], |row| row.get(0))?
            .map(|row| {
                let r: i64 = row?;
                Ok(r)
            })
            .collect::<Result<Vec<i64>>>()?;

        for mut action_id in base_actions {
            loop {
                match self
                    .sql
                    .query_row(
                        "
                            SELECT id
                            FROM actions
                            WHERE action_id=?1
                        ",
                        &[&action_id],
                        |row| row.get(0),
                    )
                    .optional()?
                {
                    Some(id) => action_id = id,
                    None => {
                        action_sets.push(self.action_set(ActionID(action_id))?);
                        break;
                    }
                }
            }
        }

        Ok(action_sets)
    }

    pub fn version(&self) -> Result<String> {
        Ok(self
            .sql
            .query_row("SELECT version FROM meta WHERE id=1", [], |row| row.get(0))?)
    }

    fn init(&self) -> Result<()> {
        if self.version().is_err() {
            self.sql.execute(
                "INSERT INTO meta (version)
                VALUES (?1)",
                &[Self::VERSION_0_1_0],
            )?;
        }

        Ok(())
    }

    pub fn register_devices(&self, devices: &Devices) -> Result<()> {
        for (device, control) in devices.plugs.iter() {
            self.sql.execute(
                &format!(
                    "INSERT INTO devices (device, type, control)
                    SELECT \"{device}\", \"plug\", ?1
                    WHERE
                        NOT EXISTS (
                            SELECT device
                            FROM devices
                            WHERE device=\"{device}\"
                        )
                "
                ),
                &[control],
            )?;

            let ctl = if *control { 1 } else { 0 };

            self.sql.execute(
                &format!(
                    "
                        UPDATE devices
                        SET control=\"{ctl}\"
                        WHERE device=\"{device}\"
                    "
                ),
                [],
            )?;
        }

        for device in devices.thermostat.iter() {
            self.sql.execute(
                &format!(
                    "INSERT INTO devices (device, type, control)
                    SELECT \"{device}\", \"thermostat\", false
                    WHERE
                        NOT EXISTS (
                            SELECT device
                            FROM devices
                            WHERE device=\"{device}\"
                        )
                "
                ),
                [],
            )?;
        }

        for device in devices.thermometer.iter() {
            self.sql.execute(
                &format!(
                    "INSERT INTO devices (device, type, control)
                    SELECT \"{device}\", \"thermometer\", false
                    WHERE
                        NOT EXISTS (
                            SELECT device
                            FROM devices
                            WHERE device=\"{device}\"
                        )
                "
                ),
                [],
            )?;
        }

        Ok(())
    }

    pub fn write(&self, device_name: &str, time: u64, name: &str, value: f32) -> Result<()> {
        let params: &[&dyn ToSql] = &[&time, &value];

        self.sql.execute(
            &format!(
                "INSERT INTO data (time, name, value, device_id)
                VALUES (?1, \"{name}\", ?2, (SELECT id FROM devices WHERE device=\"{device_name}\") )"
            ),
            params,
        )?;

        Ok(())
    }

    pub fn devices(&self) -> Result<DevicesWithName> {
        let mut devices = DevicesWithName::default();

        for row in self
            .sql
            .prepare(&format!(
                "
                    SELECT device, type, name, control
                    FROM devices
                "
            ))?
            .query_map([], |row| {
                Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?))
            })?
        {
            let (device, dev_type, name, control): (String, String, Option<String>, i32) = row?;

            match dev_type.as_str() {
                "plug" => devices.plugs.push(DeviceWithName {
                    id: device,
                    desc: name,
                    toggle: control != 0,
                }),
                "thermostat" => devices.thermostat.push(DeviceWithName {
                    id: device,
                    desc: name,
                    toggle: control != 0,
                }),
                "thermometer" => devices.temperature_and_humidity.push(DeviceWithName {
                    id: device,
                    desc: name,
                    toggle: control != 0,
                }),

                _ => panic!(),
            }
        }

        Ok(devices)
    }

    pub fn device_exists(&self, device_id: &str) -> Result<bool> {
        Ok(self
            .sql
            .prepare(&format!(
                "
                    SELECT *
                    FROM devices
                    WHERE device=\"{device_id}\"
                "
            ))?
            .exists([])?)
    }

    pub fn change_device_name(&self, device: &str, description: &str) -> Result<()> {
        self.sql.execute(
            &format!(
                "
                    UPDATE devices
                    SET name=\"{description}\"
                    WHERE device=\"{device}\"
                "
            ),
            [],
        )?;

        Ok(())
    }

    pub fn read(&self, device: &str) -> Result<Vec<(u64, f32)>> {
        self._read(&format!(
            "
            SELECT data.time, data.value
            FROM data
            INNER JOIN devices
                ON data.device_id=devices.id
            WHERE devices.device=\"{device}\"
        "
        ))
    }

    pub fn read_range(&self, device: &str, start: u64, end: u64) -> Result<Vec<(u64, f32)>> {
        self._read(&format!(
            "
            SELECT data.time, data.value
            FROM data
            INNER JOIN devices
                ON data.device_id=devices.id
            WHERE devices.device=\"{device}\"
                AND data.time>={start}
                AND data.time<{end}
        "
        ))
    }

    fn _read(&self, query: &str) -> Result<Vec<(u64, f32)>> {
        self.sql
            .prepare(query)?
            .query_map([], |row| Ok((row.get(0)?, row.get(1)?)))?
            .map(|row| {
                let (time, watts) = row?;

                Ok((time, watts))
            })
            .collect()
    }

    pub fn write_credential(&self, key: &str, device_id: u64, credential: &str) -> Result<()> {
        if self
            .sql
            .prepare(&format!(
                "
                SELECT cred
                FROM credentials
                WHERE key=\"{key}\" AND device_id={device_id}
            "
            ))?
            .exists([])?
        {
            self.sql.execute(
                &format!(
                    "
                        UPDATE credentials
                        SET cred=\"{credential}\"
                        WHERE key=\"{key}\" AND device_id={device_id}
                    "
                ),
                [],
            )?;
        } else {
            self.sql.execute(
                &format!(
                    "INSERT INTO crendetials (key, device_id, cred)
                    VALUES (\"{key}\", {device_id}, \"{credential}\")"
                ),
                [],
            )?;
        }

        Ok(())
    }

    pub fn read_credential(&self, key: &str, device_id: u64) -> Result<Option<String>> {
        Ok(self
            .sql
            .prepare(&format!(
                "
                SELECT cred
                FROM credentials
                WHERE key=\"{key}\" AND device_id={device_id}
            "
            ))?
            .query_row([], |row| Ok(row.get(0)?))
            .optional()?)
    }
}

#[cfg(test)]
mod test {
    use std::fs;

    use anyhow::Result;

    use crate::{
        action::{Action, ActionSet, ActionType},
        devices::Devices,
    };

    use super::DataBase;

    #[tokio::test]
    async fn test_connection() -> Result<()> {
        let db = DataBase::new("connection_test.db").await?;
        assert_eq!(DataBase::VERSION_0_1_0, db.version()?);

        fs::remove_file("connection_test.db")?;

        Ok(())
    }

    #[tokio::test]
    async fn test_startup() -> Result<()> {
        let db = DataBase::new("startup_test.db").await?;

        db.register_devices(&Devices {
            plugs: vec![("test".to_string(), true)],
            thermostat: Vec::new(),
            thermometer: Vec::new(),
        })?;

        fs::remove_file("startup_test.db")?;

        Ok(())
    }

    #[tokio::test]
    async fn test_write() -> Result<()> {
        let db = DataBase::new("write_test.db").await?;

        let device_name = "test";

        db.register_devices(&Devices {
            plugs: vec![(device_name.to_string(), true)],
            thermostat: Vec::new(),
            thermometer: Vec::new(),
        })?;

        db.write(device_name, 0, "watts", 5.5)?;

        let device_descriptor = "udo";
        db.change_device_name(device_name, device_descriptor)?;

        let devices = db.devices()?;

        assert_eq!(devices.plugs[0].desc.as_ref().unwrap(), device_descriptor);
        assert_eq!(devices.plugs[0].id, device_name);

        fs::remove_file("write_test.db")?;

        Ok(())
    }

    #[tokio::test]
    async fn action_set_test() -> Result<()> {
        let db = DataBase::new("action_set_test.db").await?;

        let thermometer = "shelly_plus_ht";
        let thermostat = "shelly_trv";

        db.register_devices(&Devices {
            plugs: Vec::new(),
            thermostat: vec![thermostat.to_string()],
            thermometer: vec![thermometer.to_string()],
        })?;

        let mut action_set = ActionSet::default();
        action_set.chain(Action::new(thermometer, ActionType::Push, "temperature"));
        action_set.chain(Action::new(thermostat, ActionType::Receive, "temperature"));

        let action_id = db.insert_action_set(action_set.clone())?;
        let cmp_action_set = db.action_set(action_id)?;

        assert_eq!(action_set, cmp_action_set);

        let action_sets_thermometer = db.action_sets(thermometer)?;
        let action_sets_thermostat = db.action_sets(thermostat)?;

        assert_eq!(action_sets_thermometer, action_sets_thermostat);

        fs::remove_file("action_set_test.db")?;

        Ok(())
    }
}