use crate::pb::*;

use super::git_cmd;

pub(crate) fn maintenance_response(out: std::process::Output) -> RepositoryMaintenanceResponse {
    RepositoryMaintenanceResponse {
        ok: out.status.success(),
        stdout: String::from_utf8_lossy(&out.stdout).into_owned(),
        stderr: String::from_utf8_lossy(&out.stderr).into_owned(),
    }
}

/// Get approximate repository size using git count-objects instead of
/// recursively scanning the filesystem (which is O(n) and very slow for large repos).
fn dir_size(gb: &crate::bare::GitBare) -> u64 {
    let out = git_cmd(gb, &["count-objects", "-v"]).ok();
    let text = out
        .as_ref()
        .map(|o| String::from_utf8_lossy(&o.stdout).into_owned())
        .unwrap_or_default();

    let mut loose_size_kb = 0u64;
    let mut pack_size_kb = 0u64;
    let mut garbage_size_kb = 0u64;

    for line in text.lines() {
        let line = line.trim();
        if let Some(val) = line.strip_prefix("size: ") {
            loose_size_kb = val.trim().parse().unwrap_or(0);
        } else if let Some(val) = line.strip_prefix("size-pack: ") {
            pack_size_kb = val.trim().parse().unwrap_or(0);
        } else if let Some(val) = line.strip_prefix("size-garbage: ") {
            garbage_size_kb = val.trim().parse().unwrap_or(0);
        }
    }

    // count-objects reports sizes in KiB; convert to bytes
    (loose_size_kb + pack_size_kb + garbage_size_kb) * 1024
}

fn count_refs(gb: &crate::bare::GitBare) -> u64 {
    let out = git_cmd(gb, &["for-each-ref", "--format=%(refname)"]).unwrap_or_else(|_| {
        std::process::Output {
            status: Default::default(),
            stdout: Vec::new(),
            stderr: Vec::new(),
        }
    });
    String::from_utf8_lossy(&out.stdout)
        .lines()
        .filter(|l| !l.is_empty())
        .count() as u64
}

fn file_len(path: &std::path::Path) -> u64 {
    std::fs::metadata(path).map(|m| m.len()).unwrap_or(0)
}

pub(crate) fn get_statistics(gb: &crate::bare::GitBare) -> RepositoryStatistics {
    let size_bytes = dir_size(gb);

    let mut loose_object_count: u64 = 0;
    let mut packed_object_count: u64 = 0;
    let mut packfile_count: u64 = 0;
    if let Ok(out) = git_cmd(gb, &["count-objects", "-v"]) {
        for line in String::from_utf8_lossy(&out.stdout).lines() {
            let line = line.trim();
            if let Some(v) = line.strip_prefix("count: ") {
                loose_object_count = v.trim().parse().unwrap_or(0);
            } else if let Some(v) = line.strip_prefix("in-pack: ") {
                packed_object_count = v.trim().parse().unwrap_or(0);
            } else if let Some(v) = line.strip_prefix("packs: ") {
                packfile_count = v.trim().parse().unwrap_or(0);
            }
        }
    }

    let reference_count = count_refs(gb);
    let commit_graph_size_bytes = file_len(&gb.bare_dir.join("objects/info/commit-graph"));
    let multi_pack_index_size_bytes = file_len(&gb.bare_dir.join("objects/pack/multi-pack-index"));

    RepositoryStatistics {
        size_bytes,
        loose_object_count,
        packed_object_count,
        packfile_count,
        reference_count,
        commit_graph_size_bytes,
        multi_pack_index_size_bytes,
    }
}

pub(crate) fn check_health(
    gb: &crate::bare::GitBare,
    connectivity_only: bool,
) -> Result<RepositoryHealthResponse, tonic::Status> {
    tracing::info!(
        repo = %gb.bare_dir.display(),
        connectivity_only = connectivity_only,
        "running health check"
    );
    let mut args: Vec<&str> = vec!["fsck"];
    if connectivity_only {
        args.push("--connectivity-only");
    }
    let out = git_cmd(gb, &args)?;
    let text = String::from_utf8_lossy(&out.stdout);
    let mut warnings = Vec::new();
    let mut errors = Vec::new();
    for line in text.lines() {
        if line.starts_with("error:") {
            errors.push(line.to_string());
        } else if line.starts_with("warning:") {
            warnings.push(line.to_string());
        }
    }
    Ok(RepositoryHealthResponse {
        ok: out.status.success(),
        warnings,
        errors,
        statistics: None,
    })
}

pub(crate) fn run_gc(
    gb: &crate::bare::GitBare,
    prune: bool,
    aggressive: bool,
) -> Result<RepositoryMaintenanceResponse, tonic::Status> {
    tracing::info!(
        repo = %gb.bare_dir.display(),
        prune = prune,
        aggressive = aggressive,
        "running garbage collection"
    );
    let mut args: Vec<&str> = vec!["gc"];
    if prune {
        args.push("--prune=now");
    }
    if aggressive {
        args.push("--aggressive");
    }
    let out = git_cmd(gb, &args)?;
    Ok(maintenance_response(out))
}

pub(crate) fn run_repack(
    gb: &crate::bare::GitBare,
    full: bool,
    write_bitmaps: bool,
    write_multi_pack_index: bool,
) -> Result<RepositoryMaintenanceResponse, tonic::Status> {
    tracing::info!(
        repo = %gb.bare_dir.display(),
        full = full,
        write_bitmaps = write_bitmaps,
        write_multi_pack_index = write_multi_pack_index,
        "running repack"
    );
    let mut args: Vec<&str> = vec!["repack", "-d"];
    if full {
        args.push("-a");
    }
    if write_bitmaps {
        args.push("--write-bitmap-index");
    }
    if write_multi_pack_index {
        args.push("--write-midx");
    }
    let out = git_cmd(gb, &args)?;
    Ok(maintenance_response(out))
}

pub(crate) fn run_commit_graph_write(
    gb: &crate::bare::GitBare,
    split: bool,
    replace: bool,
) -> Result<RepositoryMaintenanceResponse, tonic::Status> {
    tracing::info!(
        repo = %gb.bare_dir.display(),
        split = split,
        replace = replace,
        "writing commit-graph"
    );
    let mut args: Vec<&str> = vec!["commit-graph", "write"];
    if split {
        args.push("--split");
    }
    if !replace {
        args.push("--append");
    }
    let out = git_cmd(gb, &args)?;
    Ok(maintenance_response(out))
}