use core::fmt::Formatter;
use regex::RegexSet;
use std::env;
use std::fmt::Display;
use std::time::Duration;
use uuid::Uuid;

use turtle_common::utils::uuid_v7;

use time::OffsetDateTime;

use crate::history::secrets::SECRET_PATTERNS_RE;

pub mod builder;
mod secrets;

const HISTORY_AUTHOR_ENV: &str = "ATUIN_HISTORY_AUTHOR";
const HISTORY_INTENT_ENV: &str = "ATUIN_HISTORY_INTENT";

#[derive(Clone, Debug, Eq, PartialEq, Hash, Copy)]
pub struct HistoryId(Uuid);

impl Display for HistoryId {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.0)
    }
}

impl From<String> for HistoryId {
    fn from(s: String) -> Self {
        Self(Uuid::parse_str(&s).expect("should be a valid uuid"))
    }
}
impl From<&str> for HistoryId {
    fn from(s: &str) -> Self {
        Self(Uuid::parse_str(s).expect("should be a valid uuid"))
    }
}

/// Client-side history entry.
///
/// Client stores data unencrypted, and only encrypts it before sending to the server.
///
/// To create a new history entry, use one of the builders:
/// - [`History::import()`] to import an entry from the shell history file
/// - [`History::capture()`] to capture an entry via hook
/// - [`History::from_db()`] to create an instance from the database entry
//
// ## Implementation Notes
//
// New fields must be added to `History::{serialize,deserialize}` in a backwards
// compatible way (sensible defaults and careful `nfields` handling).
#[derive(Debug, Clone, PartialEq, Eq, sqlx::FromRow)]
pub struct History {
    /// A client-generated ID, used to identify the entry when syncing.
    ///
    /// Stored as `client_id` in the database.
    pub id: HistoryId,

    /// When the command was run.
    pub timestamp: OffsetDateTime,

    /// How long the command took to run.
    pub duration: Duration,

    /// The exit code of the command.
    pub exit: i64,

    /// The command that was run.
    pub command: String,

    /// The current working directory when the command was run.
    pub cwd: String,

    /// The session ID, associated with a terminal session.
    pub session: String,

    /// The hostname of the machine the command was run on.
    pub hostname: String,

    /// Who wrote this command (human user or automation/agent identity).
    pub author: String,

    /// Optional rationale for why the command was executed.
    pub intent: Option<String>,

    /// Timestamp, which is set when the entry is deleted, allowing a soft delete.
    pub deleted_at: Option<OffsetDateTime>,
}

impl History {
    #[must_use]
    pub fn author_from_hostname(hostname: &str) -> String {
        hostname
            .split_once(':')
            .map_or_else(|| hostname.to_owned(), |(_, user)| user.to_owned())
    }

    fn normalize_optional_field(field: Option<String>) -> Option<String> {
        field.and_then(|value| {
            let trimmed = value.trim();
            if trimmed.is_empty() {
                None
            } else {
                Some(trimmed.to_owned())
            }
        })
    }

    #[expect(clippy::too_many_arguments)]
    fn new(
        timestamp: OffsetDateTime,
        command: String,
        cwd: String,
        exit: i64,
        duration: Duration,
        session: String,
        hostname: String,
        author: Option<String>,
        intent: Option<String>,
        deleted_at: Option<OffsetDateTime>,
    ) -> Self {
        let author = Self::normalize_optional_field(author)
            .or_else(|| Self::normalize_optional_field(env::var(HISTORY_AUTHOR_ENV).ok()))
            .unwrap_or_else(|| Self::author_from_hostname(hostname.as_str()));
        let intent = Self::normalize_optional_field(intent)
            .or_else(|| Self::normalize_optional_field(env::var(HISTORY_INTENT_ENV).ok()));

        Self {
            id: uuid_v7().as_simple().to_string().into(),
            timestamp,
            command,
            cwd,
            exit,
            duration,
            session,
            hostname,
            author,
            intent,
            deleted_at,
        }
    }

    /// Builder for a history entry that is captured via hook, and sent to the daemon.
    ///
    /// This builder is used only at the `start` step of the hook,
    /// so it doesn't have any fields which are known only after
    /// the command is finished, such as `exit` or `duration`.
    ///
    /// It does, however, include information that can usually be inferred.
    ///
    /// This is because the daemon we are sending a request to lacks the context of the command
    ///
    /// ## Examples
    /// ```rust
    /// use crate::aclient::history::History;
    ///
    /// let history: History = History::daemon()
    ///     .timestamp(time::OffsetDateTime::now_utc())
    ///     .command("ls -la")
    ///     .cwd("/home/user")
    ///     .session("018deb6e8287781f9973ef40e0fde76b")
    ///     .hostname("computer:ellie")
    ///     .build()
    ///     .into();
    /// ```
    ///
    /// Command without any required info cannot be captured, which is forced at compile time:
    ///
    /// ```compile_fail
    /// use crate::aclient::history::History;
    ///
    /// // this will not compile because `hostname` is missing
    /// let history: History = History::daemon()
    ///     .timestamp(time::OffsetDateTime::now_utc())
    ///     .command("ls -la")
    ///     .cwd("/home/user")
    ///     .session("018deb6e8287781f9973ef40e0fde76b")
    ///     .build()
    ///     .into();
    /// ```
    pub fn daemon() -> builder::HistoryDaemonCaptureBuilder {
        builder::HistoryDaemonCapture::builder()
    }

    #[doc(hidden)]
    pub fn from_db() -> builder::HistoryFromDbBuilder {
        builder::HistoryFromDb::builder()
    }

    pub fn should_save(&self, filter: SettingsFilter<'_>) -> bool {
        !(self.command.is_empty()
            || filter.history.is_match(&self.command)
            || filter.cwd.is_match(&self.cwd)
            || (filter.secrets && SECRET_PATTERNS_RE.is_match(&self.command)))
    }
}

#[derive(Debug, Copy, Clone)]
pub struct SettingsFilter<'a> {
    pub history: &'a RegexSet,
    pub cwd: &'a RegexSet,
    pub secrets: bool,
}

#[cfg(test)]
mod tests {
    // use regex::RegexSet;
    //
    // use crate::history::History;

    // // Test that we don't save history where necessary
    // #[test]
    // fn privacy_test() {
    //     let settings = Settings {
    //         cwd_filter: RegexSet::new(["^/supasecret"]).unwrap(),
    //         history_filter: RegexSet::new(["^psql"]).unwrap(),
    //         ..Settings::default()
    //     };
    //
    //     let normal_command: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("echo foo")
    //         .cwd("/")
    //         .build()
    //         .into();
    //
    //     let with_space: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command(" echo bar")
    //         .cwd("/")
    //         .build()
    //         .into();
    //
    //     let empty: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("")
    //         .cwd("/")
    //         .build()
    //         .into();
    //
    //     let stripe_key: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("curl foo.com/bar?key=sk_test_1234567890abcdefghijklmnop")
    //         .cwd("/")
    //         .build()
    //         .into();
    //
    //     let secret_dir: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("echo ohno")
    //         .cwd("/supasecret")
    //         .build()
    //         .into();
    //
    //     let with_psql: History = History::daemon()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("psql")
    //         .cwd("/supasecret")
    //         .build()
    //         .into();
    //
    //     assert!(normal_command.should_save(&settings));
    //     assert!(!with_space.should_save(&settings));
    //     assert!(!empty.should_save(&settings));
    //     assert!(!stripe_key.should_save(&settings));
    //     assert!(!secret_dir.should_save(&settings));
    //     assert!(!with_psql.should_save(&settings));
    // }
    //
    // #[test]
    // fn disable_secrets() {
    //     let settings = Settings {
    //         secrets_filter: false,
    //         ..Settings::new().unwrap()
    //     };
    //
    //     let stripe_key: History = History::capture()
    //         .timestamp(time::OffsetDateTime::now_utc())
    //         .command("curl foo.com/bar?key=sk_test_1234567890abcdefghijklmnop")
    //         .cwd("/")
    //         .build()
    //         .into();
    //
    //     assert!(stripe_key.should_save(&settings));
    // }
}