//! Encapsulates a set of structures that abstract out a smart contract layout.

use alloc::{string::String, vec::Vec};

use crate::Type;

/// Contract's entrypoint.
#[derive(Debug, Clone)]
pub struct Entrypoint {
    pub ident: String,
    pub args: Vec<Argument>,
    pub is_mut: bool,
    pub ret: Type,
    pub ty: EntrypointType
}

/// Defines an argument passed to an entrypoint.
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct Argument {
    pub ident: String,
    pub ty: Type,
    pub is_ref: bool
}

/// Defines an entrypoint type.
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub enum EntrypointType {
    /// A special entrypoint that can be called just once on the contract initialization.
    Constructor { non_reentrant: bool },
    /// A regular entrypoint.
    Public { non_reentrant: bool },
    /// A payable entrypoint.
    PublicPayable { non_reentrant: bool }
}

impl EntrypointType {
    pub fn is_non_reentrant(&self) -> bool {
        match self {
            EntrypointType::Constructor { non_reentrant } => *non_reentrant,
            EntrypointType::Public { non_reentrant } => *non_reentrant,
            EntrypointType::PublicPayable { non_reentrant } => *non_reentrant
        }
    }
}

/// Defines an event.
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct Event {
    pub ident: String,
    pub args: Vec<Argument>
}

impl Event {
    pub fn has_any(&self) -> bool {
        self.args.iter().any(|arg| Type::has_any(&arg.ty))
    }
}

/// A trait that should be implemented by each smart contract to allow the backend
/// to generate blockchain-specific code.
pub trait HasEntrypoints {
    /// Returns an abstract contract definition.
    fn entrypoints() -> Vec<Entrypoint>;
}

/// A trait that should be implemented by each smart contract to allow the backend.
pub trait HasIdent {
    fn ident() -> String;
}
/// A trait that should be implemented by each smart contract to allow the backend.
pub trait HasEvents {
    fn events() -> Vec<Event>;
}

pub trait Node {
    const IS_LEAF: bool = true;
    const COUNT: u32;

    fn __keys() -> Vec<String> {
        Vec::new()
    }
}

#[derive(Debug, Clone)]
pub struct ContractBlueprint {
    pub keys: Vec<String>,
    pub keys_count: u32,
    pub events: Vec<Event>,
    pub entrypoints: Vec<Entrypoint>,
    pub fqn: &'static str
}

#[cfg(test)]
#[allow(dead_code)]
mod test {
    use super::Node;
    use alloc::{string::String, vec, vec::Vec};
    use core::marker::PhantomData;

    #[test]
    fn key_collection_works() {
        struct Variable<T> {
            ty: PhantomData<T>
        }

        impl<T> Node for Variable<T> {
            const COUNT: u32 = 1;
        }

        struct Contract {
            pub value: Variable<u32>,
            pub submodule: Submodule
        }

        impl Node for Contract {
            const COUNT: u32 = <Variable<u32> as Node>::COUNT + <Submodule as Node>::COUNT;
            const IS_LEAF: bool = false;

            fn __keys() -> Vec<String> {
                let mut result = vec![];
                // The same would be generated by the [odra::module] macro.
                if <Variable<u32> as Node>::IS_LEAF {
                    result.push(String::from("value"));
                } else {
                    result.extend(
                        <Variable<u32> as Node>::__keys()
                            .iter()
                            .map(|k| odra_utils::create_key("value", k))
                    )
                }
                if <Submodule as Node>::IS_LEAF {
                    result.push(String::from("submodule"));
                } else {
                    result.extend(
                        <Submodule as Node>::__keys()
                            .iter()
                            .map(|k| odra_utils::create_key("submodule", k))
                    )
                }
                result
            }
        }

        struct Submodule {
            abc: Variable<u32>
        }

        impl Node for Submodule {
            const COUNT: u32 = <Variable<u32> as Node>::COUNT;
            const IS_LEAF: bool = false;

            fn __keys() -> Vec<String> {
                let mut result = vec![];
                if <Variable<u32> as Node>::IS_LEAF {
                    result.push(String::from("abc"));
                } else {
                    result.extend(
                        <Variable<u32> as Node>::__keys()
                            .iter()
                            .map(|k| odra_utils::create_key("abc", k))
                    )
                }
                result
            }
        }

        assert_eq!(Contract::__keys(), ["value", "submodule#abc"])
    }
}