zagens-cli 0.8.2

use std::io::{self, IsTerminal, Read, Write};
use std::process::Command;

use std::path::Path;

use anyhow::{Result, bail};
use tempfile::NamedTempFile;

use zagens_core::chat::LlmClient;

use crate::cli::args::{ApplyArgs, ReviewArgs};
use crate::cli::auto_route_cli::resolve_cli_auto_route;
use crate::cli::context::CliContext;
use crate::client::DeepSeekClient;
use crate::models::{ContentBlock, Message, MessageRequest, SystemPrompt};
use crate::utils::truncate_with_ellipsis;

pub async fn run_review(ctx: &CliContext, args: ReviewArgs) -> Result<()> {
    let diff = collect_diff(&args)?;
    if diff.trim().is_empty() {
        bail!("No diff to review.");
    }

    let model = args
        .model
        .or_else(|| ctx.config.default_text_model.clone())
        .unwrap_or_else(|| ctx.config.default_model());
    let route = resolve_cli_auto_route(&ctx.config, &model, &diff).await;
    let model = route.model;
    let reasoning_effort = route
        .reasoning_effort
        .map(|effort| effort.as_setting().to_string());

    let system = SystemPrompt::Text(
        "You are a senior code reviewer. Focus on bugs, risks, behavioral regressions, and missing tests. \
Provide findings ordered by severity with file references, then open questions, then a brief summary."
            .to_string(),
    );
    let user_prompt =
        format!("Review the following diff and provide feedback:\n\n{diff}\n\nEnd of diff.");

    let client = DeepSeekClient::new(&ctx.config)?;
    let request = MessageRequest {
        model: model.clone(),
        messages: vec![Message {
            role: "user".to_string(),
            content: vec![ContentBlock::Text {
                text: user_prompt,
                cache_control: None,
            }],
        }],
        max_tokens: 4096,
        system: Some(system),
        tools: None,
        tool_choice: None,
        metadata: None,
        thinking: None,
        reasoning_effort,
        stream: Some(false),
        temperature: Some(0.2),
        top_p: Some(0.9),
    };

    let response = client.create_message(request).await?;
    let mut output = String::new();
    for block in response.content {
        if let ContentBlock::Text { text, .. } = block {
            output.push_str(&text);
        }
    }
    if args.json {
        println!(
            "{}",
            serde_json::to_string_pretty(&serde_json::json!({
                "mode": "review",
                "model": model,
                "success": true,
                "content": output
            }))?
        );
    } else {
        println!("{output}");
    }
    Ok(())
}

pub fn run_apply(workspace: &Path, args: ApplyArgs) -> Result<()> {
    let patch = if let Some(path) = args.patch_file {
        std::fs::read_to_string(&path)
            .map_err(|e| anyhow::anyhow!("Failed to read patch {}: {e}", path.display()))?
    } else {
        read_patch_from_stdin()?
    };
    if patch.trim().is_empty() {
        bail!("Patch is empty.");
    }

    let mut tmp = NamedTempFile::new()?;
    tmp.write_all(patch.as_bytes())?;
    let tmp_path = tmp.path().to_path_buf();

    let output = Command::new("git")
        .current_dir(workspace)
        .arg("apply")
        .arg("--whitespace=nowarn")
        .arg(&tmp_path)
        .output()
        .map_err(|e| anyhow::anyhow!("Failed to run git apply: {e}"))?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        bail!("git apply failed: {}", stderr.trim());
    }
    println!("Applied patch successfully.");
    Ok(())
}

fn collect_diff(args: &ReviewArgs) -> Result<String> {
    let mut cmd = Command::new("git");
    cmd.arg("diff");
    if args.staged {
        cmd.arg("--cached");
    }
    if let Some(base) = &args.base {
        cmd.arg(format!("{base}...HEAD"));
    }
    if let Some(path) = &args.path {
        cmd.arg("--").arg(path);
    }

    let output = cmd
        .output()
        .map_err(|e| anyhow::anyhow!("Failed to run git diff. Is git installed? ({e})"))?;
    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        bail!("git diff failed: {}", stderr.trim());
    }
    let mut diff = String::from_utf8_lossy(&output.stdout).to_string();
    if diff.len() > args.max_chars {
        diff = truncate_with_ellipsis(&diff, args.max_chars, "\n...[truncated]\n");
    }
    Ok(diff)
}

fn read_patch_from_stdin() -> Result<String> {
    let mut stdin = io::stdin();
    if stdin.is_terminal() {
        bail!("No patch file provided and stdin is empty.");
    }
    let mut buffer = String::new();
    stdin.read_to_string(&mut buffer)?;
    Ok(buffer)
}