use serde::Deserialize;
use serde::Serialize;

pub fn running_template() -> TemplateSpec {
    TemplateSpec::Table(vec![
        Column {
            display_name: Some("Date".to_string()),
            field: FieldSpec::App(
                Function::DisplayUnit(Unit::Timestamp, "date".to_string()),
                vec![FieldSpec::Field("start_time".to_string())],
            ),
        },
        Column {
            display_name: Some("Time".to_string()),
            field: FieldSpec::App(
                Function::DisplayUnit(Unit::Seconds, "".to_string()),
                vec![FieldSpec::Field("moving_time".to_string())],
            ),
        },
        Column {
            display_name: Some("Distance".to_string()),
            field: FieldSpec::App(
                Function::DisplayUnit(Unit::Meters, "miles".to_string()),
                vec![FieldSpec::Field("distance".to_string())],
            ),
        },
        Column {
            display_name: Some("Pace".to_string()),
            field: FieldSpec::App(
                Function::DisplayUnit(Unit::Pace, "".to_string()),
                vec![FieldSpec::App(
                    Function::Div,
                    vec![
                        FieldSpec::Field("moving_time".to_string()),
                        FieldSpec::Field("distance".to_string()),
                    ],
                )],
            ),
        },
    ])
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub enum Unit {
    Timestamp, // As Rfc3339
    Meters,
    Seconds,
    Speed, // As m/s
    Pace,  // As s/m
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub enum Function {
    TimestampToDate,
    DisplayUnit(Unit, String),
    Div,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub enum FieldSpec {
    Field(String),
    App(Function, Vec<FieldSpec>),
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct Column {
    display_name: Option<String>,
    field: FieldSpec,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub enum TemplateSpec {
    Table(Vec<Column>),
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct Template {
    pub entry_type: String,
    pub spec: TemplateSpec,
}