use std::{fmt::Debug, path::{Path, PathBuf}, fs::File, io::{Read, BufReader, BufRead, Write}, collections::{HashMap, HashSet}, net::Ipv4Addr};
use anyhow::{Context, bail, anyhow};
use clap::Parser;
use json::JsonValue;
use regex::Regex;

use crate::run::{BENCH_BASE_PATH, BENCH_DATA_PATH};

fn json_from_file<P>(path: P) -> anyhow::Result<HashMap<String, f64>>
where
    P: Debug,
    P: AsRef<Path>
{
    if !path.as_ref().exists() {
        return Ok(HashMap::new());
    }
    let mut vec = vec![];
    File::open(&path)
        .context(format!("Failed to open {:?}", path))?
        .read_to_end(&mut vec)?;
    let json_val = json::parse(String::from_utf8(vec)?.as_str())?;
    let json_obj = if let JsonValue::Object(o) = json_val {
        o
    } else {
        bail!("Expected json object, got: {}", json_val);
    };
    let mut map = HashMap::new();
    for (key, val) in json_obj.iter() {
        let val: f64 = match val {
            JsonValue::Number(n) => {
                f64::from(*n)
            },
            JsonValue::String(_) | JsonValue::Short(_) => {
                val.as_str()
                   .unwrap()
                   .strip_suffix("%")
                   .ok_or(anyhow!("Expected percentage String, got: {:?}", val))?
                   .parse()?
            },
            _ => bail!("Expected json number or string, got: {:?}", val),
        };
        map.insert(String::from(key), val);
    }
    Ok(map)
}

fn ips_from_file<P>(path: P) -> anyhow::Result<HashSet<Ipv4Addr>>
where
    P: Debug,
    P: AsRef<Path>
{
    let f = File::open(path)?;
    let reader = BufReader::new(f);
    let mut hashset = HashSet::new();
    for line in reader.lines() {
        let line = line?;
        hashset.insert(line.parse()?);
    }

    Ok(hashset)
}

fn parse_rate(rate: &str, unit: &str) -> anyhow::Result<f64> {
    let multiplier = match unit {
        "G" => 1_000_000_000f64,
        "M" => 1_000_000f64,
        "K" => 1_000f64,
        "" => 1f64,
        m => bail!("Unknown unit {} (rate: {})", m, rate)
    };

    let rate: f64 = rate.parse()?;
    return Ok(rate * multiplier)
}

fn zmap_stats<P>(path: P, regex: &Regex) -> anyhow::Result<(f64, f64, f64)>
where
    P: Debug,
    P: AsRef<Path>
{
    let f = File::open(path)?;
    let reader = BufReader::new(f);
    let mut rates = None;
    for line in reader.lines() {
        let line = line?;
        if let Some(capture) = regex.captures(&line) {
            let result: anyhow::Result<_> = (|| {
                let send_rate = capture
                    .get(1)
                    .ok_or(anyhow!("Capture group 1 did not match"))?;
                let send_rate_unit = capture
                    .get(2)
                    .ok_or(anyhow!("Capture group 2 did not match"))?;
                let send_rate = parse_rate(send_rate.as_str(), send_rate_unit.as_str())?;

                let receive_rate = capture
                    .get(3)
                    .ok_or(anyhow!("Capture group 3 did not match"))?;
                let receive_rate_unit = capture
                    .get(4)
                    .ok_or(anyhow!("Capture group 4 did not match"))?;
                let receive_rate = parse_rate(receive_rate.as_str(), receive_rate_unit.as_str())?;

                let drop_rate = capture
                    .get(5)
                    .ok_or(anyhow!("Capture group 5 did not match"))?;
                let drop_rate_unit = capture
                    .get(6)
                    .ok_or(anyhow!("Capture group 6 did not match"))?;
                let drop_rate = parse_rate(drop_rate.as_str(), drop_rate_unit.as_str())?;


                Ok((send_rate, receive_rate, drop_rate))
            })();
            rates = Some(result.context(format!("Failed to parse stats line: '{}'", line))?);
        }
    }
    rates.ok_or(anyhow!("Failed to find final stats line"))
}

#[derive(Debug, Parser)]
pub struct Options {
    seed: String
}

pub fn process(opts: Options) -> anyhow::Result<()> {
    let mut path = PathBuf::new();
    path.push(BENCH_BASE_PATH);
    path.push(BENCH_DATA_PATH);
    path.push(opts.seed);

    let zmap_stats_regex = Regex::new(r"^[^\(;]+(?:\(.+left\))?; send: [^\(;]+done \(([\d\.]+) ([KMG]?)p/s avg\); recv: [^\(;]+\(([\d\.]+) ([KMG]?)p/s avg\); drops: [^\(;]+\(([\d\.]+) ([KMG]?)p/s avg\); hitrate: [^;]+$")?;

    let header_row = [
        "type", "filter-type",
        "subnet_size", "hitrate", "bloom_filter_bits", "bloom_filter_hash_count", "zmap_scanrate",
        "bpf_run_time_total", "bpf_run_count", "bpf_memory_lock",
        "filter_intern_build_time", "filter_intern_write_time",
        "filter_extern_time_clock", "filter_extern_cpu_p", "filter_extern_kernel_secs", "filter_extern_user_secs",
        "zmap_send_rate", "zmap_receive_rate", "zmap_drop_rate",
        "false_positive_count", "false_negative_count"
    ];
    let mut data_rows = vec![];
    data_rows.push(header_row.map(str::to_string));

    for subnet_dir in path.read_dir().context(format!("Failed to read subnet dirs in path {:?}", &path))? {
        let subnet_dir = subnet_dir.context(format!("Failed to read file info on file in path {:?}", &path))?;
        if !subnet_dir
            .file_type()
            .context(format!("Failed to read file info on file {:?}", subnet_dir.path()))?
            .is_dir() {
                bail!("Expected dir at {:?}", subnet_dir.path())
            }
        let subnet = subnet_dir.file_name().into_string().map_err(|e| anyhow!(format!("{:?}", e)))?;
        for hitrate_dir in subnet_dir.path().read_dir().context(format!("Failed to read hitrate dirs in path {:?}", subnet_dir.path()))? {
            let hitrate_dir = hitrate_dir.context(format!("Failed to read file info on file in path {:?}",subnet_dir.path()))?;
            if !hitrate_dir
                .file_type()
                .context(format!("Failed to read file info on file {:?}", hitrate_dir.path()))?
                .is_dir() {
                    bail!("Expected dir at {:?}", hitrate_dir.path())
                }
            let hitrate = hitrate_dir.file_name().into_string().map_err(|e| anyhow!(format!("{:?}", e)))?;
            let in_ips = ips_from_file(hitrate_dir.path().join("ips.txt")).context(format!("Failed to read ips from {:?}/ips.txt", hitrate_dir.path()))?;
            for bloom_dir in hitrate_dir.path().read_dir().context(format!("Failed to read bloom dirs in path {:?}", hitrate_dir.path()))? {
                let bloom_dir = bloom_dir.context(format!("Failed to read file info on file in path {:?}", hitrate_dir.path()))?;
                if !bloom_dir
                    .file_type()
                    .context(format!("Failed to read file info on file {:?}", bloom_dir.path()))?
                    .is_dir() {
                        continue;
                    }
                let bloom_folder_name = bloom_dir
                    .file_name()
                    .into_string()
                    .map_err(|e| anyhow!(format!("{:?}", e)))?;
                let (test_type, filter_type, bloom_bits, bloom_hashes) = if bloom_folder_name.contains('-') {
                    let (bloom_bits, rem) = bloom_folder_name.split_once("-")
                                                             .ok_or(anyhow!("Expected filename with -, got {:?}", bloom_dir.file_name()))?;

                    let (filter_type, rem) = rem.split_once("-").unwrap_or((rem, ""));

                    let (bloom_hashes, bpf_enabled) = if filter_type == "bloom" {
                        rem.split_once("-").map(|(c, rem)| (c,rem=="bpf")).unwrap_or((rem, false))
                    } else {
                        ("0", rem == "bpf")
                    };

                    let bloom_bits = bloom_bits.to_string();
                    let bloom_hashes = bloom_hashes.to_string();
                    let test_type = if bpf_enabled {
                        "bpf-stats"
                    } else {
                        "normal"
                    };
                    (test_type, filter_type, bloom_bits, bloom_hashes)
                } else {
                    ("baseline","none", String::from("-1"), String::from("-1"))
                };

                let bloom_path = bloom_dir.path();

                let mut filter_intern_time = json_from_file(bloom_path.join("filter_intern_time.json"))
                    .context(format!("Failed to parse filter_intern_time.json for {:?}", bloom_path))?;
                let mut filter_extern_time = json_from_file(bloom_path.join("filter_extern_time.json"))
                    .context(format!("Failed to parse filter_extern_time.json  for {:?}", bloom_path))?;

                for scan_rate_dir in bloom_dir.path().read_dir().context(format!("Failed to read scan rate dirs in path {:?}", bloom_dir.path()))? {
                    let scan_rate_dir = scan_rate_dir.context(format!("Failed to read file info on file in path {:?}", bloom_dir.path()))?;
                    if !scan_rate_dir
                        .file_type()
                        .context(format!("Failed to read file info on file {:?}", scan_rate_dir.path()))?
                        .is_dir() {
                            continue;
                        }
                    let scan_rate = scan_rate_dir.file_name().to_str().unwrap().to_string();

                    let wd_path = scan_rate_dir.path();
                    let mut bpf_stats = json_from_file(wd_path.join("bpf_stats.json"))
                        .context(format!("Failed to parse bpf_stats.json for {:?}", wd_path))?;
                    let out_ips = ips_from_file(wd_path.join("zmap_out_ips.txt"))
                        .context(format!("Failed to parse zmap_out_ips.txt from {:?}", wd_path))?;
                    let zmap_stats = zmap_stats(wd_path.join("zmap_stats.txt"), &zmap_stats_regex)
                        .context(format!("Failed to parse zmap_stats.txt from {:?}", wd_path))?;

                    let get_or_default = |map: &mut HashMap<String, f64>, k: &str| map
                        .get(k).unwrap_or(&-1f64).to_string();

                    let data_row = (|| {
                        Ok([
                            test_type.to_owned(),
                            filter_type.to_owned(),
                            subnet.clone(), hitrate.clone(), bloom_bits.clone(), bloom_hashes.clone(), scan_rate.clone(),
                            get_or_default(&mut bpf_stats, "run_time"),
                            get_or_default(&mut bpf_stats, "run_count"),
                            get_or_default(&mut bpf_stats, "mem_lock"),
                            get_or_default(&mut filter_intern_time, "build"),
                            get_or_default(&mut filter_intern_time, "write"),
                            get_or_default(&mut filter_extern_time, "clock"),
                            get_or_default(&mut filter_extern_time, "cpu_p"),
                            get_or_default(&mut filter_extern_time, "kernel_s"),
                            get_or_default(&mut filter_extern_time, "user_s"),
                            zmap_stats.0.to_string(),
                            zmap_stats.1.to_string(),
                            zmap_stats.2.to_string(),
                            out_ips.difference(&in_ips).count().to_string(),
                            in_ips.difference(&out_ips).count().to_string(),
                        ])
                    })().map_err(|key: String| {
                        anyhow!("Failed to read data point {} for {:?}", key, wd_path)
                    })?;

                    let mut f = File::create(wd_path.join("data_row.csv"))?;
                    f.write_all(header_row.join(",").as_bytes())?;
                    f.write(&[b'\n'])?;
                    f.write_all(data_row.join(",").as_bytes())?;
                    data_rows.push(data_row);

                }
            }
        }
    }

    let data = data_rows.into_iter()
             .map(|row| row.join(","))
             .fold(String::new(), |a, b| a + &b + "\n");


    File::create(path.join("data.csv"))?.write_all(data.as_bytes())?;


    Ok(())
}