use serde::{Deserialize, Serialize};
use serde_yaml_ng::{Mapping, Sequence, Value};

#[derive(Debug, Clone, Default, Serialize, Deserialize)]
pub struct SeqMap {
    pub prepend: Sequence,
    pub append: Sequence,
    pub delete: Vec<String>,
}

pub fn use_seq(seq: SeqMap, mut config: Mapping, field: &str) -> Mapping {
    let SeqMap {
        prepend,
        append,
        delete,
    } = seq;

    let mut new_seq = Sequence::new();
    new_seq.extend(prepend);

    if let Some(Value::Sequence(origin)) = config.get(field) {
        // Filter out deleted items
        let filtered: Sequence = origin
            .iter()
            .filter(|item| {
                if let Value::String(s) = item {
                    !delete.contains(s)
                } else if let Value::Mapping(m) = item {
                    if let Some(Value::String(name)) = m.get("name") {
                        !delete.contains(name)
                    } else {
                        true
                    }
                } else {
                    true
                }
            })
            .cloned()
            .collect();
        new_seq.extend(filtered);
    }

    new_seq.extend(append);
    config.insert(Value::String(field.into()), Value::Sequence(new_seq));

    // If this is proxies field, we also need to filter proxy-groups
    if field == "proxies"
        && let Some(Value::Sequence(groups)) = config.get_mut("proxy-groups")
    {
        let mut new_groups = Sequence::new();
        for group in groups {
            if let Value::Mapping(group_map) = group {
                let mut new_group = group_map.clone();
                if let Some(Value::Sequence(proxies)) = group_map.get("proxies") {
                    let filtered_proxies: Sequence = proxies
                        .iter()
                        .filter(|p| {
                            if let Value::String(name) = p {
                                !delete.contains(name)
                            } else {
                                true
                            }
                        })
                        .cloned()
                        .collect();
                    new_group.insert(
                        Value::String("proxies".into()),
                        Value::Sequence(filtered_proxies),
                    );
                }
                new_groups.push(Value::Mapping(new_group));
            } else {
                new_groups.push(group.clone());
            }
        }
        config.insert(
            Value::String("proxy-groups".into()),
            Value::Sequence(new_groups),
        );
    }

    config
}

#[cfg(test)]
mod tests {
    use super::*;
    #[allow(unused_imports)]
    use serde_yaml_ng::Value;

    #[test]
    #[allow(clippy::unwrap_used)]
    #[allow(clippy::expect_used)]
    fn test_delete_proxy_and_references() {
        let config_str = r#"
proxies:
- name: "proxy1"
  type: "ss"
- name: "proxy2"
  type: "vmess"
proxy-groups:
- name: "group1"
  type: "select"
  proxies:
    - "proxy1"
    - "proxy2"
- name: "group2"
  type: "select"
  proxies:
    - "proxy1"
"#;
        let mut config: Mapping =
            serde_yaml_ng::from_str(config_str).expect("Failed to parse test config YAML");

        let seq = SeqMap {
            prepend: Sequence::new(),
            append: Sequence::new(),
            delete: vec!["proxy1".to_string()],
        };

        config = use_seq(seq, config, "proxies");

        // Check if proxy1 is removed from proxies
        let proxies = config
            .get("proxies")
            .expect("proxies field should exist")
            .as_sequence()
            .expect("proxies should be a sequence");
        assert_eq!(proxies.len(), 1);
        assert_eq!(
            proxies[0]
                .as_mapping()
                .expect("proxy should be a mapping")
                .get("name")
                .expect("proxy should have name")
                .as_str()
                .expect("name should be string"),
            "proxy2"
        );

        // Check if proxy1 is removed from all groups
        let groups = config
            .get("proxy-groups")
            .expect("proxy-groups field should exist")
            .as_sequence()
            .expect("proxy-groups should be a sequence");
        let group1_proxies = groups[0]
            .as_mapping()
            .expect("group should be a mapping")
            .get("proxies")
            .expect("group should have proxies")
            .as_sequence()
            .expect("group proxies should be a sequence");
        let group2_proxies = groups[1]
            .as_mapping()
            .expect("group should be a mapping")
            .get("proxies")
            .expect("group should have proxies")
            .as_sequence()
            .expect("group proxies should be a sequence");

        assert_eq!(group1_proxies.len(), 1);
        assert_eq!(
            group1_proxies[0]
                .as_str()
                .expect("proxy name should be string"),
            "proxy2"
        );
        assert_eq!(group2_proxies.len(), 0);
    }
}