use std::fmt::Display;

use anyhow::Result;
use chrono::{DateTime, Utc};
use derive_builder::Builder;
use sqlx::{
    error::BoxDynError,
    postgres::{PgRow, PgTypeInfo, PgValueRef},
    ColumnIndex, Decode, Postgres, Row as _, TypeInfo as _, ValueRef as _,
};
use uuid::Uuid;

pub enum Value {
    Text(Option<String>),
    Integer(Option<i32>),
    Timestamptz(Option<DateTime<Utc>>),
    Uuid(Option<Uuid>),
}

#[derive(Builder)]
#[builder(pattern = "owned", setter(prefix = "with"))]
pub struct FieldOptions {
    /// Format with which to render timestamptz values
    #[builder(default = "\"%Y-%m-%dT%H:%M:%S%.f%:z\".to_owned()")]
    pub date_format: String,

    /// If some, treat text column like an enum
    #[builder(default)]
    pub select_options: Option<Vec<String>>,

    /// Text to display in place of actual column name
    #[builder(default)]
    pub label: Option<String>,

    #[builder(default = "true")]
    pub editable: bool,
}

pub trait ToHtmlString {
    fn to_html_string(&self, options: &FieldOptions) -> String;
}

#[derive(Clone, Debug)]
pub struct FromSqlError {
    message: String,
}

impl std::error::Error for FromSqlError {}

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

impl FromSqlError {
    fn new(message: &str) -> Self {
        Self {
            message: message.to_owned(),
        }
    }
}

impl Value {
    pub fn get_from_row<I: ColumnIndex<PgRow> + Display>(
        row: &PgRow,
        idx: I,
    ) -> Result<Self, BoxDynError> {
        let value_ref = row.try_get_raw(idx)?;
        Self::decode(value_ref)
    }
}

impl ToHtmlString for Value {
    fn to_html_string(&self, options: &FieldOptions) -> String {
        macro_rules! cell_html {
            ($component:expr, $value:expr$(, $attr_name:expr => $attr_val:expr)*) => {
                {
                    let value = $value.clone();
                    let attrs: Vec<String> = vec![
                        format!("value=\"{}\"", serde_json::to_string(&value).unwrap().replace('"', "\\\"")),
                        $(format!("{}=\"{}\"", $attr_name, $attr_val.replace('"', "\\\"")),)*
                    ];
                    format!(
                        "<{} {}>{}</{}>",
                        $component,
                        attrs.join(" "),
                        value.map(|value| value.to_string()).unwrap_or("-".to_owned()),
                        $component,
                    )
                }
            };
        }
        match self {
            Self::Text(value) => cell_html!("cell-text", value),
            Self::Integer(value) => cell_html!("cell-integer", value),
            Self::Timestamptz(value) => cell_html!(
                "cell-timestamptz",
                value,
                "format" => options.date_format
            ),
            Self::Uuid(value) => cell_html!("cell-uuid", value),
        }
    }
}

impl sqlx::Type<Postgres> for Value {
    fn type_info() -> <Postgres as sqlx::Database>::TypeInfo {
        PgTypeInfo::with_name("XXX");
        todo!()
    }
}

impl<'a> Decode<'a, Postgres> for Value {
    fn decode(value: PgValueRef<'a>) -> Result<Self, BoxDynError> {
        let type_info = value.type_info();
        let ty = type_info.name();
        match ty {
            "INT" | "INT4" => Ok(Self::Integer(if value.is_null() {
                None
            } else {
                Some(<i32 as Decode<Postgres>>::decode(value)?)
            })),
            "TEXT" | "VARCHAR" => Ok(Self::Text(if value.is_null() {
                None
            } else {
                Some(<String as Decode<Postgres>>::decode(value)?)
            })),
            "TIMESTAMPTZ" => Ok(Self::Timestamptz(if value.is_null() {
                None
            } else {
                Some(<DateTime<Utc> as Decode<Postgres>>::decode(value)?)
            })),
            "UUID" => Ok(Self::Uuid(if value.is_null() {
                None
            } else {
                Some(<Uuid as Decode<Postgres>>::decode(value)?)
            })),
            _ => Err(Box::new(FromSqlError::new(
                "unsupported pg type for interim Value",
            ))),
        }
    }
}

pub struct Lens {
    pub fields: Vec<Field>,
}

pub struct Field {
    pub options: FieldOptions,
    pub name: String,
}