use anyhow::{Context, Result};
use std::process::Command;
use std::string::ToString;

#[derive(Debug, Clone)]
pub struct GitCommit {
    pub old_path: Option<String>,
    pub new_path: Option<String>,
    pub sha: String,
    pub message: String,
    pub author: String,
}

pub fn get_recent_commits(limit: usize) -> Result<Vec<GitCommit>> {
    let output = Command::new("git")
        .args(&[
            "log",
            "--pretty=format:%H|%s|%an",
            &format!("-n{}", limit),
        ])
        .output()
        .context("Failed to execute git log")?;

    if !output.status.success() {
        return Err(anyhow::anyhow!("Git log command failed"));
    }

    let stdout = String::from_utf8_lossy(&output.stdout);
    let mut commits = Vec::new();

    for line in stdout.lines() {
        let parts: Vec<&str> = line.splitn(3, "|").collect();
        if parts.len() >= 3 {
            commits.push(GitCommit {
                old_path: None,
                new_path: None,
                sha: parts[0].to_string(),
                message: parts[1].to_string(),
                author: parts[2].to_string(),
            });
        }
    }

    Ok(commits)
}

pub fn get_diff_from_sha(sha: &str) -> Result<Vec<Change>> {
    let output = Command::new("git")
        .args(&["show", "--stat", sha])
        .output()
        .context("Failed to execute git show")?;

    if !output.status.success() {
        return Err(anyhow::anyhow!("Git show command failed"));
    }

    let stdout = String::from_utf8_lossy(&output.stdout);
    let mut changes = Vec::new();

    for line in stdout.lines() {
        if line.contains("|") {
            let parts: Vec<&str> = line.split("|").collect();
            if parts.len() == 2 {
                let path_parts: Vec<&str> = parts[0].split(" -> ").collect();
                let (old_path, new_path) = if path_parts.len() == 2 {
                    (Some(path_parts[0].to_string()), Some(path_parts[1].to_string()))
                } else {
                    (None, Some(parts[0].to_string()))
                };

                changes.push(Change {
                    old_path,
                    new_path,
                    additions: 0,
                    deletions: 0,
                });
            }
        }
    }

    Ok(changes)
}

#[derive(Debug)]
pub struct Change {
    pub old_path: Option<String>,
    pub new_path: Option<String>,
    pub additions: usize,
    pub deletions: usize,
}

pub fn get_staged_diff() -> Result<Vec<Change>> {
    let output = Command::new("git")
        .args(&["diff", "--cached", "--stat"])
        .output()
        .context("Failed to execute git diff --cached")?;

    if !output.status.success() {
        return Err(anyhow::anyhow!("Git diff command failed"));
    }

    let stdout = String::from_utf8_lossy(&output.stdout);
    let mut changes = Vec::new();

    for line in stdout.lines() {
        let parts: Vec<&str> = line.split("|").collect();
        if parts.len() == 2 {
            let path_parts: Vec<&str> = parts[0].split(" -> ").collect();
            let (old_path, new_path) = if path_parts.len() == 2 {
                (Some(path_parts[0].to_string()), Some(path_parts[1].to_string()))
            } else {
                (None, Some(parts[0].to_string()))
            };

            let stat_parts: Vec<&str> = parts[1].trim().split(" ").collect();
            let mut additions = 0;
            let mut deletions = 0;

            for stat in stat_parts {
                if stat.contains('+') && stat.parse::<usize>().is_ok() {
                    additions = stat.replace('+', "").parse().unwrap_or(0);
                }
                if stat.contains('-') && stat.parse::<usize>().is_ok() {
                    deletions = stat.replace('-', "").parse().unwrap_or(0);
                }
            }

            changes.push(Change {
                old_path,
                new_path,
                additions,
                deletions,
            });
        }
    }

    Ok(changes)
}

pub fn get_diff_stats() -> Result<(usize, usize)> {
    let output = Command::new("git")
        .args(&["diff", "--shortstat"])
        .output()
        .context("Failed to execute git diff")?;

    if !output.status.success() {
        return Err(anyhow::anyhow!("Git diff command failed"));
    }

    let stdout = String::from_utf8_lossy(&output.stdout);
    let mut insertions = 0;
    let mut deletions = 0;

    for line in stdout.lines() {
        let parts: Vec<&str> = line.split(",").collect();
        for part in parts {
            let part = part.trim();
            if let Some(insertions_str) = part.strip_suffix(" insertions(+)") {
                if let Ok(count) = insertions_str.trim().parse::<usize>() {
                    insertions = count;
                }
            }
            if let Some(deletions_str) = part.strip_suffix(" deletions(-)") {
                if let Ok(count) = deletions_str.trim().parse::<usize>() {
                    deletions = count;
                }
            }
        }
    }

    Ok((insertions, deletions))
}