#[cfg(feature = "serde1")]
use serde::{Deserialize, Serialize};
use std::io::BufRead;

use super::ProcResult;
use crate::{process::Pfn, split_into_num};

#[derive(Debug, PartialEq, Eq, Clone, Hash)]
#[cfg_attr(feature = "serde1", derive(Serialize, Deserialize))]
pub struct Iomem(pub Vec<(usize, PhysicalMemoryMap)>);

impl crate::FromBufRead for Iomem {
    fn from_buf_read<R: BufRead>(r: R) -> ProcResult<Self> {
        let mut vec = Vec::new();

        for line in r.lines() {
            let line = expect!(line);

            let (indent, map) = PhysicalMemoryMap::from_line(&line)?;

            vec.push((indent, map));
        }

        Ok(Iomem(vec))
    }
}

#[derive(Debug, PartialEq, Eq, Clone, Hash)]
#[cfg_attr(feature = "serde1", derive(Serialize, Deserialize))]
pub struct PhysicalMemoryMap {
    /// The address space in the process that the mapping occupies.
    pub address: (u64, u64),
    pub name: String,
}

impl PhysicalMemoryMap {
    fn from_line(line: &str) -> ProcResult<(usize, PhysicalMemoryMap)> {
        let indent = line.chars().take_while(|c| *c == ' ').count() / 2;
        let line = line.trim();
        let mut s = line.split(" : ");
        let address = expect!(s.next());
        let name = expect!(s.next());

        Ok((
            indent,
            PhysicalMemoryMap {
                address: split_into_num(address, '-', 16)?,
                name: String::from(name),
            },
        ))
    }

    /// Get the PFN range for the mapping
    ///
    /// First element of the tuple (start) is included.
    /// Second element (end) is excluded
    pub fn get_range(&self) -> impl crate::WithSystemInfo<Output = (Pfn, Pfn)> {
        move |si: &crate::SystemInfo| {
            let start = self.address.0 / si.page_size();
            let end = (self.address.1 + 1) / si.page_size();

            (Pfn(start), Pfn(end))
        }
    }
}