use std::env;

use chrono::Utc;

use atuin_common::utils::uuid_v7;

mod builder;

/// 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 should be added to `encryption::{encode, decode}` in a backwards
// compatible way. (eg sensible defaults and updating the nfields parameter)
#[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: String,
    /// When the command was run.
    pub timestamp: chrono::DateTime<Utc>,
    /// How long the command took to run.
    pub duration: i64,
    /// 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,
    /// Timestamp, which is set when the entry is deleted, allowing a soft delete.
    pub deleted_at: Option<chrono::DateTime<Utc>>,
}

impl History {
    #[allow(clippy::too_many_arguments)]
    fn new(
        timestamp: chrono::DateTime<Utc>,
        command: String,
        cwd: String,
        exit: i64,
        duration: i64,
        session: Option<String>,
        hostname: Option<String>,
        deleted_at: Option<chrono::DateTime<Utc>>,
    ) -> Self {
        let session = session
            .or_else(|| env::var("ATUIN_SESSION").ok())
            .unwrap_or_else(|| uuid_v7().as_simple().to_string());
        let hostname = hostname.unwrap_or_else(|| {
            format!(
                "{}:{}",
                env::var("ATUIN_HOST_NAME").unwrap_or_else(|_| whoami::hostname()),
                env::var("ATUIN_HOST_USER").unwrap_or_else(|_| whoami::username())
            )
        });

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

    /// Builder for a history entry that is imported from shell history.
    ///
    /// The only two required fields are `timestamp` and `command`.
    ///
    /// ## Examples
    /// ```
    /// use atuin_client::history::History;
    ///
    /// let history: History = History::import()
    ///     .timestamp(chrono::Utc::now())
    ///     .command("ls -la")
    ///     .build()
    ///     .into();
    /// ```
    ///
    /// If shell history contains more information, it can be added to the builder:
    /// ```
    /// use atuin_client::history::History;
    ///
    /// let history: History = History::import()
    ///     .timestamp(chrono::Utc::now())
    ///     .command("ls -la")
    ///     .cwd("/home/user")
    ///     .exit(0)
    ///     .duration(100)
    ///     .build()
    ///     .into();
    /// ```
    ///
    /// Unknown command or command without timestamp cannot be imported, which
    /// is forced at compile time:
    ///
    /// ```compile_fail
    /// use atuin_client::history::History;
    ///
    /// // this will not compile because timestamp is missing
    /// let history: History = History::import()
    ///     .command("ls -la")
    ///     .build()
    ///     .into();
    /// ```
    pub fn import() -> builder::HistoryImportedBuilder {
        builder::HistoryImported::builder()
    }

    /// Builder for a history entry that is captured via hook.
    ///
    /// 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`.
    ///
    /// ## Examples
    /// ```rust
    /// use atuin_client::history::History;
    ///
    /// let history: History = History::capture()
    ///     .timestamp(chrono::Utc::now())
    ///     .command("ls -la")
    ///     .cwd("/home/user")
    ///     .build()
    ///     .into();
    /// ```
    ///
    /// Command without any required info cannot be captured, which is forced at compile time:
    ///
    /// ```compile_fail
    /// use atuin_client::history::History;
    ///
    /// // this will not compile because `cwd` is missing
    /// let history: History = History::capture()
    ///     .timestamp(chrono::Utc::now())
    ///     .command("ls -la")
    ///     .build()
    ///     .into();
    /// ```
    pub fn capture() -> builder::HistoryCapturedBuilder {
        builder::HistoryCaptured::builder()
    }

    /// Builder for a history entry that is imported from the database.
    ///
    /// All fields are required, as they are all present in the database.
    ///
    /// ```compile_fail
    /// use atuin_client::history::History;
    ///
    /// // this will not compile because `id` field is missing
    /// let history: History = History::from_db()
    ///     .timestamp(chrono::Utc::now())
    ///     .command("ls -la".to_string())
    ///     .cwd("/home/user".to_string())
    ///     .exit(0)
    ///     .duration(100)
    ///     .session("somesession".to_string())
    ///     .hostname("localhost".to_string())
    ///     .deleted_at(None)
    ///     .build()
    ///     .into();
    /// ```
    pub fn from_db() -> builder::HistoryFromDbBuilder {
        builder::HistoryFromDb::builder()
    }

    pub fn success(&self) -> bool {
        self.exit == 0 || self.duration == -1
    }
}