purple-ssh 1.27.0

use std::sync::atomic::{AtomicBool, Ordering};

use serde::Deserialize;

use super::{Provider, ProviderError, ProviderHost, map_ureq_error};

pub struct Linode;

#[derive(Deserialize)]
struct LinodeResponse {
    data: Vec<LinodeInstance>,
    page: u64,
    pages: u64,
}

#[derive(Deserialize)]
struct LinodeInstance {
    id: u64,
    label: String,
    #[serde(default)]
    ipv4: Vec<String>,
    #[serde(default)]
    ipv6: Option<String>,
    #[serde(default)]
    tags: Vec<String>,
    #[serde(default)]
    region: String,
    #[serde(default, rename = "type")]
    instance_type: String,
    #[serde(default)]
    status: String,
    #[serde(default)]
    image: Option<String>,
}

/// Check if an IP address is in a private/reserved range.
fn is_private_ip(ip: &str) -> bool {
    ip.starts_with("10.")
        || ip.starts_with("192.168.")
        || ip.starts_with("127.")
        || (ip.starts_with("172.")
            && ip
                .split('.')
                .nth(1)
                .and_then(|s| s.parse::<u8>().ok())
                .is_some_and(|n| (16..=31).contains(&n)))
        || (ip.starts_with("100.")
            && ip
                .split('.')
                .nth(1)
                .and_then(|s| s.parse::<u8>().ok())
                .is_some_and(|n| (64..=127).contains(&n)))
}

impl Provider for Linode {
    fn name(&self) -> &str {
        "linode"
    }

    fn short_label(&self) -> &str {
        "linode"
    }

    fn fetch_hosts_cancellable(
        &self,
        token: &str,
        cancel: &AtomicBool,
    ) -> Result<Vec<ProviderHost>, ProviderError> {
        let mut all_hosts = Vec::new();
        let mut page = 1u64;
        let agent = super::http_agent();

        loop {
            if cancel.load(Ordering::Relaxed) {
                return Err(ProviderError::Cancelled);
            }

            let url = format!(
                "https://api.linode.com/v4/linode/instances?page={}&page_size=500",
                page
            );
            let resp: LinodeResponse = agent
                .get(&url)
                .set("Authorization", &format!("Bearer {}", token))
                .call()
                .map_err(map_ureq_error)?
                .into_json()
                .map_err(|e| ProviderError::Parse(e.to_string()))?;

            if resp.data.is_empty() {
                break;
            }

            for instance in &resp.data {
                // Prefer public IPv4; fall back to private IPv4, then IPv6
                let ip = instance
                    .ipv4
                    .iter()
                    .find(|ip| !is_private_ip(ip))
                    .or_else(|| instance.ipv4.first())
                    .cloned()
                    .or_else(|| {
                        instance
                            .ipv6
                            .as_ref()
                            .filter(|v| !v.is_empty())
                            .map(|v| super::strip_cidr(v).to_string())
                    });
                if let Some(ip) = ip {
                    if !ip.is_empty() {
                        let mut metadata = Vec::new();
                        if !instance.region.is_empty() {
                            metadata.push(("region".to_string(), instance.region.clone()));
                        }
                        if !instance.instance_type.is_empty() {
                            metadata.push(("plan".to_string(), instance.instance_type.clone()));
                        }
                        if let Some(ref image) = instance.image {
                            if !image.is_empty() {
                                metadata.push(("os".to_string(), image.clone()));
                            }
                        }
                        if !instance.status.is_empty() {
                            metadata.push(("status".to_string(), instance.status.clone()));
                        }
                        all_hosts.push(ProviderHost {
                            server_id: instance.id.to_string(),
                            name: instance.label.clone(),
                            ip,
                            tags: instance.tags.clone(),
                            metadata,
                        });
                    }
                }
            }

            if resp.page >= resp.pages {
                break;
            }
            page += 1;
            if page > 500 {
                break;
            }
        }

        Ok(all_hosts)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_is_private_ip() {
        assert!(is_private_ip("10.0.0.1"));
        assert!(is_private_ip("192.168.1.1"));
        assert!(is_private_ip("172.16.0.1"));
        assert!(is_private_ip("172.31.255.255"));
        assert!(is_private_ip("100.64.0.1"));
        assert!(is_private_ip("127.0.0.1"));
        assert!(!is_private_ip("1.2.3.4"));
        assert!(!is_private_ip("172.15.0.1"));
        assert!(!is_private_ip("172.32.0.1"));
        assert!(!is_private_ip("100.63.0.1"));
    }

    #[test]
    fn test_parse_linode_prefers_public_ip() {
        let json = r#"{
            "data": [
                {
                    "id": 111,
                    "label": "mixed-ips",
                    "ipv4": ["192.168.1.1", "5.6.7.8"],
                    "tags": []
                }
            ],
            "page": 1,
            "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        let instance = &resp.data[0];
        let ip = instance
            .ipv4
            .iter()
            .find(|ip| !is_private_ip(ip))
            .or_else(|| instance.ipv4.first());
        assert_eq!(ip.unwrap(), "5.6.7.8");
    }

    #[test]
    fn test_parse_linode_response() {
        let json = r#"{
            "data": [
                {
                    "id": 111,
                    "label": "app-server",
                    "ipv4": ["9.8.7.6", "192.168.1.1"],
                    "tags": ["production"]
                },
                {
                    "id": 222,
                    "label": "no-ip-server",
                    "ipv4": [],
                    "tags": []
                }
            ],
            "page": 1,
            "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data.len(), 2);
        assert_eq!(resp.data[0].label, "app-server");
        assert_eq!(resp.data[0].ipv4[0], "9.8.7.6");
        assert!(resp.data[1].ipv4.is_empty());
    }

    // Helper: same IP selection logic as fetch_hosts_cancellable
    fn select_linode_ip(instance: &LinodeInstance) -> Option<String> {
        instance
            .ipv4
            .iter()
            .find(|ip| !is_private_ip(ip))
            .or_else(|| instance.ipv4.first())
            .cloned()
            .or_else(|| {
                instance
                    .ipv6
                    .as_ref()
                    .filter(|v| !v.is_empty())
                    .map(|v| crate::providers::strip_cidr(v).to_string())
            })
    }

    #[test]
    fn test_is_private_ip_100_range_boundary() {
        // 100.64-127 is CGNAT (private), 100.63 and 100.128 are public
        assert!(is_private_ip("100.64.0.1"));
        assert!(is_private_ip("100.127.255.255"));
        assert!(!is_private_ip("100.63.255.255"));
        assert!(!is_private_ip("100.128.0.1"));
    }

    #[test]
    fn test_is_private_ip_172_range_boundary() {
        assert!(is_private_ip("172.16.0.1"));
        assert!(is_private_ip("172.31.0.1"));
        assert!(!is_private_ip("172.15.0.1"));
        assert!(!is_private_ip("172.32.0.1"));
    }

    #[test]
    fn test_linode_private_only_falls_back_to_private() {
        let json = r#"{
            "data": [{"id": 1, "label": "private-only", "ipv4": ["192.168.1.1"], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        // When no public IP, falls back to first private IP
        assert_eq!(select_linode_ip(&resp.data[0]), Some("192.168.1.1".to_string()));
    }

    #[test]
    fn test_linode_no_ips_at_all() {
        let json = r#"{
            "data": [{"id": 1, "label": "empty", "ipv4": [], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), None);
    }

    #[test]
    fn test_linode_ipv6_null() {
        let json = r#"{
            "data": [{"id": 1, "label": "null-v6", "ipv4": [], "ipv6": null, "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), None);
    }

    #[test]
    fn test_linode_ipv6_empty_string() {
        let json = r#"{
            "data": [{"id": 1, "label": "empty-v6", "ipv4": [], "ipv6": "", "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), None);
    }

    #[test]
    fn test_linode_pagination_continues() {
        let json = r#"{
            "data": [{"id": 1, "label": "a", "ipv4": ["1.1.1.1"], "tags": []}],
            "page": 1, "pages": 5
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert!(resp.page < resp.pages);
    }

    #[test]
    fn test_linode_pagination_stops() {
        let json = r#"{
            "data": [{"id": 1, "label": "a", "ipv4": ["1.1.1.1"], "tags": []}],
            "page": 5, "pages": 5
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert!(resp.page >= resp.pages);
    }

    #[test]
    fn test_linode_tags_preserved() {
        let json = r#"{
            "data": [{"id": 1, "label": "tagged", "ipv4": ["1.1.1.1"], "tags": ["web", "prod"]}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data[0].tags, vec!["web", "prod"]);
    }

    #[test]
    fn test_linode_multiple_public_ips_uses_first() {
        let json = r#"{
            "data": [{"id": 1, "label": "multi", "ipv4": ["1.2.3.4", "5.6.7.8"], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), Some("1.2.3.4".to_string()));
    }

    #[test]
    fn test_linode_ipv6_cidr_stripped() {
        let json = r#"{
            "data": [{"id": 1, "label": "v6-cidr", "ipv4": [], "ipv6": "2600:3c00::1/128", "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), Some("2600:3c00::1".to_string()));
    }

    #[test]
    fn test_linode_ipv6_no_cidr() {
        let json = r#"{
            "data": [{"id": 1, "label": "v6-bare", "ipv4": [], "ipv6": "2600:3c00::1", "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(select_linode_ip(&resp.data[0]), Some("2600:3c00::1".to_string()));
    }

    #[test]
    fn test_linode_public_ipv4_preferred_over_ipv6() {
        let json = r#"{
            "data": [{
                "id": 1, "label": "dual",
                "ipv4": ["1.2.3.4"],
                "ipv6": "2600:3c00::1/128",
                "tags": []
            }],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        // Public IPv4 is not private, so it wins over IPv6
        assert_eq!(select_linode_ip(&resp.data[0]), Some("1.2.3.4".to_string()));
    }

    #[test]
    fn test_linode_missing_ipv6_field() {
        // When ipv6 is not in the JSON at all
        let json = r#"{
            "data": [{"id": 1, "label": "no-v6", "ipv4": ["5.6.7.8"], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data[0].ipv6, None);
        assert_eq!(select_linode_ip(&resp.data[0]), Some("5.6.7.8".to_string()));
    }

    #[test]
    fn test_linode_empty_label() {
        let json = r#"{
            "data": [{"id": 1, "label": "", "ipv4": ["1.2.3.4"], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data[0].label, "");
    }

    #[test]
    fn test_linode_default_tags_empty() {
        let json = r#"{
            "data": [{"id": 1, "label": "a", "ipv4": ["1.1.1.1"]}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert!(resp.data[0].tags.is_empty());
    }

    #[test]
    fn test_linode_cgnat_100_64_is_private() {
        // CGNAT range: 100.64.0.0 - 100.127.255.255
        assert!(is_private_ip("100.64.0.0"));
        assert!(is_private_ip("100.100.50.25"));
        assert!(is_private_ip("100.127.255.255"));
    }

    #[test]
    fn test_linode_large_id() {
        let json = r#"{
            "data": [{"id": 99999999999, "label": "big", "ipv4": ["1.2.3.4"], "tags": []}],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data[0].id, 99999999999);
    }

    #[test]
    fn test_linode_empty_data_stops_pagination() {
        let json = r#"{
            "data": [],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert!(resp.data.is_empty());
    }

    #[test]
    fn test_linode_private_ip_first_then_public() {
        // API may return private IP before public in ipv4 array
        let json = r#"{
            "data": [{
                "id": 1, "label": "mixed",
                "ipv4": ["192.168.1.1", "10.0.0.1", "8.8.8.8"],
                "tags": []
            }],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        // Should find 8.8.8.8 as first non-private IP
        assert_eq!(select_linode_ip(&resp.data[0]), Some("8.8.8.8".to_string()));
    }

    #[test]
    fn test_is_private_ip_loopback() {
        assert!(is_private_ip("127.0.0.1"));
        assert!(is_private_ip("127.255.255.255"));
    }

    #[test]
    fn test_is_private_ip_public_ranges() {
        assert!(!is_private_ip("8.8.8.8"));
        assert!(!is_private_ip("1.1.1.1"));
        assert!(!is_private_ip("203.0.113.1"));
        assert!(!is_private_ip("198.51.100.1"));
    }

    #[test]
    fn test_is_private_ip_172_all_boundary_octets() {
        // 172.16-31 are private
        for n in 16..=31 {
            assert!(
                is_private_ip(&format!("172.{}.0.1", n)),
                "172.{}.0.1 should be private",
                n
            );
        }
        // 172.0-15 and 172.32+ are public
        assert!(!is_private_ip("172.0.0.1"));
        assert!(!is_private_ip("172.15.255.255"));
        assert!(!is_private_ip("172.32.0.1"));
        assert!(!is_private_ip("172.255.0.1"));
    }

    #[test]
    fn test_linode_all_private_falls_back_to_first() {
        let json = r#"{
            "data": [{
                "id": 1, "label": "all-private",
                "ipv4": ["10.0.0.1", "192.168.1.1", "172.16.0.1"],
                "tags": []
            }],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        // No public IP found, falls back to first in list
        assert_eq!(select_linode_ip(&resp.data[0]), Some("10.0.0.1".to_string()));
    }

    #[test]
    fn test_linode_private_v4_and_v6_prefers_private_v4() {
        // When only private IPv4 and public IPv6 available, private IPv4 wins
        // because the code prefers any v4 (public or private) over v6
        let json = r#"{
            "data": [{
                "id": 1, "label": "priv-v4-pub-v6",
                "ipv4": ["192.168.1.1"],
                "ipv6": "2600:3c00::1/128",
                "tags": []
            }],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        // Private v4 wins over public v6 (fallback to first v4)
        assert_eq!(select_linode_ip(&resp.data[0]), Some("192.168.1.1".to_string()));
    }

    #[test]
    fn test_linode_multiple_instances_parsed() {
        let json = r#"{
            "data": [
                {"id": 1, "label": "web-1", "ipv4": ["1.1.1.1"], "tags": ["web"]},
                {"id": 2, "label": "web-2", "ipv4": ["2.2.2.2"], "tags": ["web"]},
                {"id": 3, "label": "db", "ipv4": [], "ipv6": "2600::1/128", "tags": ["db"]}
            ],
            "page": 1, "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        assert_eq!(resp.data.len(), 3);
        assert_eq!(select_linode_ip(&resp.data[0]), Some("1.1.1.1".to_string()));
        assert_eq!(select_linode_ip(&resp.data[2]), Some("2600::1".to_string()));
    }

    #[test]
    fn test_ipv6_only_instance_uses_v6() {
        let json = r#"{
            "data": [
                {
                    "id": 333,
                    "label": "v6-only",
                    "ipv4": [],
                    "ipv6": "2600:3c00::1/128",
                    "tags": []
                }
            ],
            "page": 1,
            "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        let instance = &resp.data[0];
        let ip = instance
            .ipv4
            .iter()
            .find(|ip| !is_private_ip(ip))
            .or_else(|| instance.ipv4.first())
            .cloned()
            .or_else(|| {
                instance
                    .ipv6
                    .as_ref()
                    .filter(|v| !v.is_empty())
                    .map(|v| crate::providers::strip_cidr(v).to_string())
            });
        // CIDR suffix must be stripped for SSH compatibility
        assert_eq!(ip, Some("2600:3c00::1".to_string()));
    }

    // --- empty ipv4 and empty ipv6 → None ---

    #[test]
    fn test_linode_empty_ipv4_empty_ipv6_returns_none() {
        let json = r#"{
            "data": [{
                "id": 1,
                "label": "no-ip",
                "ipv4": [],
                "ipv6": "",
                "tags": []
            }],
            "page": 1,
            "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        let instance = &resp.data[0];
        let ip = instance
            .ipv4
            .iter()
            .find(|ip| !is_private_ip(ip))
            .or_else(|| instance.ipv4.first())
            .cloned()
            .or_else(|| {
                instance
                    .ipv6
                    .as_ref()
                    .filter(|v| !v.is_empty())
                    .map(|v| crate::providers::strip_cidr(v).to_string())
            });
        assert_eq!(ip, None);
    }

    // --- ipv6 field omitted (defaults to None) → falls through ---

    #[test]
    fn test_linode_ipv6_field_omitted_falls_to_private() {
        let json = r#"{
            "data": [{
                "id": 2,
                "label": "null-v6",
                "ipv4": ["10.0.0.1"],
                "tags": []
            }],
            "page": 1,
            "pages": 1
        }"#;
        let resp: LinodeResponse = serde_json::from_str(json).unwrap();
        let instance = &resp.data[0];
        assert!(instance.ipv6.is_none());
        // Should fall back to private ipv4
        let ip = instance
            .ipv4
            .iter()
            .find(|ip| !is_private_ip(ip))
            .or_else(|| instance.ipv4.first())
            .cloned();
        assert_eq!(ip, Some("10.0.0.1".to_string()));
    }

    // --- 100.63 is NOT CGNAT (boundary) ---

    #[test]
    fn test_is_private_ip_100_63_not_cgnat() {
        assert!(!is_private_ip("100.63.0.1"));
    }

    // --- 100.128 is NOT CGNAT (boundary) ---

    #[test]
    fn test_is_private_ip_100_128_not_cgnat() {
        assert!(!is_private_ip("100.128.0.1"));
    }

    // --- 172.15 is NOT private (below range) ---

    #[test]
    fn test_is_private_ip_172_15_not_private() {
        assert!(!is_private_ip("172.15.0.1"));
    }

    // --- 172.32 is NOT private (above range) ---

    #[test]
    fn test_is_private_ip_172_32_not_private() {
        assert!(!is_private_ip("172.32.0.1"));
    }

    // --- non-numeric second octet for 172.x ---

    #[test]
    fn test_is_private_ip_172_nonnumeric() {
        assert!(!is_private_ip("172.abc.0.1"));
    }
}