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use fidl::unpersist;
use fidl_cf_sc_internal_scenemanagerstructuredconfig::Config as FidlConfig;
use fuchsia_inspect::{ArrayProperty, Node};
use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
use fuchsia_zircon as zx;
#[derive(Debug)]
pub struct Config {
    pub display_pixel_density: String,
    pub display_rotation: u64,
    pub supported_input_devices: Vec<String>,
    pub viewing_distance: String,
}
impl Config {
    pub fn take_from_startup_handle() -> Self {
        let config_vmo: zx::Vmo =
            take_startup_handle(HandleInfo::new(HandleType::ComponentConfigVmo, 0))
                .expect("Config VMO handle must be provided and cannot already have been taken.")
                .into();
        let config_size =
            config_vmo.get_content_size().expect("must be able to read config vmo content size");
        assert_ne!(config_size, 0, "config vmo must be non-empty");
        let mut config_bytes = Vec::new();
        config_bytes.resize(config_size as usize, 0);
        config_vmo.read(&mut config_bytes, 0).expect("must be able to read config vmo");
        let checksum_length = u16::from_le_bytes([config_bytes[0], config_bytes[1]]) as usize;
        let fidl_start = 2 + checksum_length;
        let observed_checksum = &config_bytes[2..fidl_start];
        let expected_checksum = vec![
            0xb3, 0x9b, 0x17, 0xc2, 0xe9, 0x8d, 0x0b, 0x70, 0xbe, 0x46, 0xe3, 0x93, 0xd4, 0x2d,
            0xb3, 0x02, 0x2c, 0xf1, 0xeb, 0xcb, 0x1a, 0xe1, 0x1a, 0x39, 0xbe, 0x24, 0x03, 0x71,
            0xcc, 0x7b, 0x6d, 0x26,
        ];
        assert_eq!(
            observed_checksum, expected_checksum,
            "checksum from config VMO does not match expected checksum"
        );
        let fidl_config: FidlConfig = unpersist(&config_bytes[fidl_start..])
            .expect("must be able to parse bytes as config FIDL");
        Self {
            display_pixel_density: fidl_config.display_pixel_density,
            display_rotation: fidl_config.display_rotation,
            supported_input_devices: fidl_config.supported_input_devices,
            viewing_distance: fidl_config.viewing_distance,
        }
    }
    pub fn record_inspect(&self, inspector_node: &Node) {
        inspector_node.record_string("display_pixel_density", &self.display_pixel_density);
        inspector_node.record_uint("display_rotation", self.display_rotation);
        let arr = inspector_node
            .create_string_array("supported_input_devices", self.supported_input_devices.len());
        for i in 0..self.supported_input_devices.len() {
            arr.set(i, &self.supported_input_devices[i]);
        }
        inspector_node.record(arr);
        inspector_node.record_string("viewing_distance", &self.viewing_distance);
    }
}