use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Default)]
#[serde(rename_all = "lowercase")]
pub enum JobType {
    #[default]
    Shell,
    Agent,
}

impl From<JobType> for &'static str {
    fn from(value: JobType) -> Self {
        match value {
            JobType::Shell => "shell",
            JobType::Agent => "agent",
        }
    }
}

impl TryFrom<&str> for JobType {
    type Error = String;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        match value.to_lowercase().as_str() {
            "shell" => Ok(JobType::Shell),
            "agent" => Ok(JobType::Agent),
            _ => Err(format!(
                "Invalid job type '{}'. Expected one of: 'shell', 'agent'",
                value
            )),
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Default)]
#[serde(rename_all = "lowercase")]
pub enum SessionTarget {
    #[default]
    Isolated,
    Main,
}

impl SessionTarget {
    pub(crate) fn as_str(&self) -> &'static str {
        match self {
            Self::Isolated => "isolated",
            Self::Main => "main",
        }
    }

    pub(crate) fn parse(raw: &str) -> Self {
        if raw.eq_ignore_ascii_case("main") {
            Self::Main
        } else {
            Self::Isolated
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(tag = "kind", rename_all = "lowercase")]
pub enum Schedule {
    Cron {
        expr: String,
        #[serde(default)]
        tz: Option<String>,
    },
    At {
        at: DateTime<Utc>,
    },
    Every {
        every_ms: u64,
    },
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct DeliveryConfig {
    #[serde(default)]
    pub mode: String,
    #[serde(default)]
    pub channel: Option<String>,
    #[serde(default)]
    pub to: Option<String>,
    #[serde(default = "default_true")]
    pub best_effort: bool,
}

impl Default for DeliveryConfig {
    fn default() -> Self {
        Self {
            mode: "none".to_string(),
            channel: None,
            to: None,
            best_effort: true,
        }
    }
}

fn default_true() -> bool {
    true
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CronJob {
    pub id: String,
    pub expression: String,
    pub schedule: Schedule,
    pub command: String,
    pub prompt: Option<String>,
    pub name: Option<String>,
    pub job_type: JobType,
    pub session_target: SessionTarget,
    pub model: Option<String>,
    pub enabled: bool,
    pub delivery: DeliveryConfig,
    pub delete_after_run: bool,
    pub created_at: DateTime<Utc>,
    pub next_run: DateTime<Utc>,
    pub last_run: Option<DateTime<Utc>>,
    pub last_status: Option<String>,
    pub last_output: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CronRun {
    pub id: i64,
    pub job_id: String,
    pub started_at: DateTime<Utc>,
    pub finished_at: DateTime<Utc>,
    pub status: String,
    pub output: Option<String>,
    pub duration_ms: Option<i64>,
}

#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct CronJobPatch {
    pub schedule: Option<Schedule>,
    pub command: Option<String>,
    pub prompt: Option<String>,
    pub name: Option<String>,
    pub enabled: Option<bool>,
    pub delivery: Option<DeliveryConfig>,
    pub model: Option<String>,
    pub session_target: Option<SessionTarget>,
    pub delete_after_run: Option<bool>,
}

#[cfg(test)]
mod tests {
    use super::JobType;

    #[test]
    fn job_type_try_from_accepts_known_values_case_insensitive() {
        assert_eq!(JobType::try_from("shell").unwrap(), JobType::Shell);
        assert_eq!(JobType::try_from("SHELL").unwrap(), JobType::Shell);
        assert_eq!(JobType::try_from("agent").unwrap(), JobType::Agent);
        assert_eq!(JobType::try_from("AgEnT").unwrap(), JobType::Agent);
    }

    #[test]
    fn job_type_try_from_rejects_invalid_values() {
        assert!(JobType::try_from("").is_err());
        assert!(JobType::try_from("unknown").is_err());
    }
}
