use crate::deserialize_error;
use convert_case::{Case, Casing};

use crate::deserialize::util::{get_as_bool, make_build_fn_name, unwrap_single_member_hash};
use crate::spec::struct_spec::*;
use yaml_rust2::Yaml;

fn deserialize_skip_child(props: &Yaml) -> StructChild {
    let rule = props["rule"].as_str().unwrap();
    StructChild::SkipChild(SkipChild::new(rule))
}

fn deserialize_vec_child(child_name: &str, props: &Yaml) -> StructChild {
    let rule = props["rule"].as_str().unwrap();
    let kind = props["kind"].as_str().unwrap_or(rule);
    if kind == "string" {
        let build = VecChildBuild::String(VecChildStringBuild::new(&make_build_fn_name(rule)));
        StructChild::VecChild(VecChild::new(child_name, rule, Box::new(build)))
    } else {
        let build = VecChildBuild::Node(VecChildNodeBuild::new(rule, &make_build_fn_name(rule)));
        StructChild::VecChild(VecChild::new(child_name, rule, Box::new(build)))
    }
}

fn deserialize_member_build(child_name: &str, rule: &str, props: &Yaml) -> MemberChildBuild {
    if props["node"].is_hash() {
        let node_props = &props["node"];
        let kind = node_props["kind"].as_str().unwrap_or(rule);
        let with = node_props["with"]
            .as_str()
            .map(|with| make_build_fn_name(with))
            .unwrap_or_else(|| make_build_fn_name(kind));

        let or_else = if get_as_bool(&node_props["or_else_default"]) {
            Some(String::from("default"))
        } else if let Some(or_else) = node_props["or_else"].as_str() {
            Some(or_else.to_string())
        } else {
            None
        };

        MemberChildBuild::Node(NodeMemberBuild::new(kind, &with, or_else))
    } else if props["boolean"].is_hash() {
        let boolean_props = &props["boolean"];
        if let Some(on) = boolean_props["on"].as_str() {
            if on == "rule_present" {
                MemberChildBuild::Boolean(BooleanMemberBuild::new(
                    BooleanMemberBuildOn::RulePresent,
                ))
            } else {
                panic!(
                    "Expected 'on' in 'boolean' in 'build' in {} to be 'rule_present'",
                    child_name
                );
            }
        } else {
            panic!("Expected 'on' in 'boolean' in 'build' in {}", child_name);
        }
    } else {
        panic!(
            "Expected one of 'node', 'boolean', or 'special' in 'build' in {}",
            child_name
        );
    }
}

fn deserialize_member_child(child_name: &str, props: &Yaml) -> StructChild {
    let rule = props["rule"]
        .as_str()
        .map(ToString::to_string)
        .unwrap_or_else(|| child_name.to_case(Case::Pascal));
    let optional = get_as_bool(&props["optional"]);
    if props["build"].is_hash() {
        let build = deserialize_member_build(child_name, &rule, &props["build"]);
        StructChild::MemberChild(MemberChild::new(
            child_name,
            &rule,
            optional,
            Box::new(build),
        ))
    } else {
        StructChild::MemberChild(MemberChild::new(
            child_name,
            &rule,
            optional,
            Box::new(MemberChildBuild::Node(NodeMemberBuild::new(
                &rule,
                &make_build_fn_name(&rule),
                None,
            ))),
        ))
    }
}

fn deserialize_special_child(name: &str, props: &Yaml) -> StructChild {
    match props["kind"].as_str().unwrap() {
        "file_id" => StructChild::Special(SpecialChild::new(name, SpecialChildKind::FileId)),
        "range" => StructChild::Special(SpecialChild::new(name, SpecialChildKind::Range)),
        _ => panic!("Invalid special child kind {} in {}", props["kind"].as_str().unwrap(), name),
    }    
}

fn deserialize_hash_child(name: &str, props: &Yaml) -> StructChild {
    if props["skip"].is_hash() {
        deserialize_skip_child(&props["skip"])
    } else if props["vec"].is_hash() {
        deserialize_vec_child(name, &props["vec"])
    } else if props["member"].is_hash() {
        deserialize_member_child(name, &props["member"])
    } else if props["special"].is_hash() {
        deserialize_special_child(name, &props["special"])    
    } else {
        panic!("Expected 'skip' or 'vec' in 'member' in {}", name);
    }
}

fn deserialize_string_child(name: &str) -> StructChild {
    let name_pascal = name.to_case(Case::Pascal);
    StructChild::MemberChild(MemberChild::new(
        name,
        &name_pascal,
        false,
        Box::new(MemberChildBuild::Node(NodeMemberBuild::new(
            &name_pascal,
            &make_build_fn_name(name),
            None,
        ))),
    ))
}

fn deserialize_children(children_yaml: &Yaml) -> Vec<Box<StructChild>> {
    children_yaml
        .as_vec()
        .unwrap()
        .iter()
        .map(|child_yaml| {
            if let Some(name) = child_yaml.as_str() {
                deserialize_string_child(name)
            } else {
                let (child_name, child_props) = unwrap_single_member_hash(child_yaml);
                deserialize_hash_child(&child_name, child_props)
            }
        })
        .map(Box::new)
        .collect()
}

pub fn deserialize_struct_spec(name: &str, struct_yaml: &Yaml) -> StructSpec {
    let children = if struct_yaml["children"].is_array() {
        deserialize_children(&struct_yaml["children"])
    } else {
        deserialize_error!("array", "children", name);
    };
    let derive = if struct_yaml["derive"].is_array() {
        struct_yaml["derive"].as_vec()
            .unwrap()
            .iter()
            .map(|derive| derive.as_str().unwrap().to_string())
            .collect()
    } else {
        vec![]
    };
    
    StructSpec::new(name, children, derive)
}