//! Git 节点 — 执行 git CLI 命令(branch/checkout/commit/merge/push/status/log)
//!
//! 通过 df_execute::shell::execute 调用本地 git CLI,working_dir 指定仓库路径。
//! 不内嵌 git2/libgit2:CLI 路径更通用、调试透明,与 ScriptNode 一致。

use async_trait::async_trait;
use df_workflow::node::{Node, NodeContext, NodeOutput, NodeResult, NodeSchema};

/// Git 节点
pub struct GitNode;

/// 支持的 Git 动作
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum GitAction {
    Branch,
    Checkout,
    Commit,
    Merge,
    Push,
    Status,
    Log,
}

impl GitAction {
    /// 从 config.action 字符串解析动作,非法值返回 Err。
    pub fn parse(raw: &str) -> anyhow::Result<Self> {
        match raw {
            "branch" => Ok(GitAction::Branch),
            "checkout" => Ok(GitAction::Checkout),
            "commit" => Ok(GitAction::Commit),
            "merge" => Ok(GitAction::Merge),
            "push" => Ok(GitAction::Push),
            "status" => Ok(GitAction::Status),
            "log" => Ok(GitAction::Log),
            other => anyhow::bail!(
                "GitNode 非法 action: {}（合法值: branch|checkout|commit|merge|push|status|log）",
                other
            ),
        }
    }

    fn as_str(&self) -> &'static str {
        match self {
            GitAction::Branch => "branch",
            GitAction::Checkout => "checkout",
            GitAction::Commit => "commit",
            GitAction::Merge => "merge",
            GitAction::Push => "push",
            GitAction::Status => "status",
            GitAction::Log => "log",
        }
    }
}

/// 从 NodeContext.config 解析出的 GitNode 参数。
/// 抽离此结构便于单元测试 config 解析逻辑(无需构造完整 NodeContext / 起 shell)。
#[derive(Debug, Clone)]
pub struct GitParams {
    pub action: GitAction,
    /// 目标分支(branch/checkout/merge)
    pub branch_name: Option<String>,
    /// commit 信息(commit)
    pub message: Option<String>,
    /// 仓库路径(None=当前目录)
    pub working_dir: Option<String>,
}

/// 从 config JSON 解析 GitParams。action 必填;其余按需。
pub fn parse_params(config: &serde_json::Value) -> anyhow::Result<GitParams> {
    let action = config
        .get("action")
        .and_then(|v| v.as_str())
        .ok_or_else(|| anyhow::anyhow!("GitNode 缺少必填参数: action"))?;
    let action = GitAction::parse(action)?;

    let branch_name = config
        .get("branch_name")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string());

    let message = config
        .get("message")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string());

    let working_dir = config
        .get("working_dir")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string());

    Ok(GitParams {
        action,
        branch_name,
        message,
        working_dir,
    })
}

/// 根据 action + 参数构建 git CLI 命令字符串。working_dir 由 ShellRequest 处理,此处不含 cd。
fn build_command(params: &GitParams) -> anyhow::Result<String> {
    match params.action {
        GitAction::Branch => {
            // 无 branch_name → 列出所有本地分支;有 → 创建新分支
            match &params.branch_name {
                Some(name) => Ok(format!("git branch {}", shell_quote(name))),
                None => Ok("git branch".to_string()),
            }
        }
        GitAction::Checkout => {
            let name = params
                .branch_name
                .as_deref()
                .ok_or_else(|| anyhow::anyhow!("GitNode action=checkout 缺少 branch_name"))?;
            Ok(format!("git checkout {}", shell_quote(name)))
        }
        GitAction::Commit => {
            let msg = params
                .message
                .as_deref()
                .ok_or_else(|| anyhow::anyhow!("GitNode action=commit 缺少 message"))?;
            Ok(format!("git commit -m {}", shell_quote(msg)))
        }
        GitAction::Merge => {
            let name = params
                .branch_name
                .as_deref()
                .ok_or_else(|| anyhow::anyhow!("GitNode action=merge 缺少 branch_name"))?;
            Ok(format!("git merge {}", shell_quote(name)))
        }
        GitAction::Push => Ok("git push".to_string()),
        GitAction::Status => Ok("git status".to_string()),
        GitAction::Log => Ok("git log --oneline -20".to_string()),
    }
}

/// 简单 shell 引号包裹:含空格/特殊字符时用双引号包裹并转义内嵌双引号。
/// 仅用于内部参数拼接(branch_name/message),命令名固定白名单不用户可控。
fn shell_quote(s: &str) -> String {
    if s.chars().any(|c| c.is_whitespace() || c == '"' || c == '$' || c == '`') {
        format!("\"{}\"", s.replace('"', "\\\""))
    } else {
        s.to_string()
    }
}

#[async_trait]
impl Node for GitNode {
    async fn execute(&self, ctx: NodeContext) -> NodeResult {
        tracing::info!("GitNode 执行: node_id={}", ctx.node_id);

        let params = parse_params(&ctx.config)?;
        let command = build_command(&params)?;

        tracing::info!(
            action = params.action.as_str(),
            working_dir = ?params.working_dir,
            "GitNode 构建命令: {}",
            command
        );

        let request = df_execute::shell::ShellRequest {
            command,
            working_dir: params.working_dir.clone(),
            env: std::collections::HashMap::new(),
            timeout_secs: Some(60),
            shell_type: Default::default(),
        };

        let result = df_execute::shell::execute(request).await?;

        let exit_code = result.exit_code.unwrap_or(-1);
        if exit_code != 0 {
            anyhow::bail!(
                "GitNode 执行失败 (exit_code={}): {}",
                exit_code,
                result.stderr.trim()
            );
        }

        // 按 action 提取结构化字段(branch 列表/commit hash 等),无法解析时回退原始 stdout。
        let parsed = parse_action_output(&params.action, &result.stdout);

        tracing::info!(
            action = params.action.as_str(),
            exit_code,
            duration_ms = result.duration_ms,
            "GitNode 完成"
        );

        Ok(NodeOutput::from_value(serde_json::json!({
            "action": params.action.as_str(),
            "stdout": result.stdout,
            "stderr": result.stderr,
            "exit_code": exit_code,
            "duration_ms": result.duration_ms,
            "parsed": parsed,
        })))
    }

    fn schema(&self) -> NodeSchema {
        NodeSchema {
            params: serde_json::json!({
                "type": "object",
                "properties": {
                    "action": {
                        "type": "string",
                        "enum": ["branch", "checkout", "commit", "merge", "push", "status", "log"]
                    },
                    "branch_name": { "type": "string", "description": "目标分支(branch/checkout/merge)" },
                    "message": { "type": "string", "description": "commit 信息(commit)" },
                    "working_dir": { "type": "string", "description": "git 仓库路径(可选)" }
                },
                "required": ["action"]
            }),
            output: serde_json::json!({
                "type": "object",
                "properties": {
                    "action": { "type": "string" },
                    "stdout": { "type": "string" },
                    "stderr": { "type": "string" },
                    "exit_code": { "type": "integer" },
                    "duration_ms": { "type": "integer" },
                    "parsed": { "type": "object" }
                }
            }),
        }
    }

    fn node_type(&self) -> &str {
        "git"
    }
}

/// 按 action 解析 stdout 成结构化字段。
/// - branch(无参列出):每行一个分支,`*` 标记当前分支
/// - log:每行一条 `hash subject`
/// - commit:首段 hash
/// - 其余动作无强结构,返回空对象
fn parse_action_output(action: &GitAction, stdout: &str) -> serde_json::Value {
    match action {
        GitAction::Branch => {
            let branches: Vec<&str> = stdout.lines().map(|l| l.trim_start_matches("* ").trim()).collect();
            let current = stdout
                .lines()
                .find(|l| l.starts_with('*'))
                .map(|l| l.trim_start_matches("* ").trim().to_string());
            serde_json::json!({ "branches": branches, "current": current })
        }
        GitAction::Log => {
            let entries: Vec<serde_json::Value> = stdout
                .lines()
                .filter_map(|l| {
                    let l = l.trim();
                    let mut parts = l.splitn(2, ' ');
                    let hash = parts.next()?.to_string();
                    let subject = parts.next().unwrap_or("").to_string();
                    Some(serde_json::json!({ "hash": hash, "subject": subject }))
                })
                .collect();
            serde_json::json!({ "entries": entries })
        }
        GitAction::Commit => {
            // `git commit` 默认输出含 `[branch hash]` 形式;取首个 7+ 位十六进制段
            let hash = stdout
                .split_whitespace()
                .find(|t| t.len() >= 7 && t.chars().all(|c| c.is_ascii_hexdigit()))
                .unwrap_or("")
                .to_string();
            serde_json::json!({ "commit_hash": hash })
        }
        _ => serde_json::json!({}),
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    // ── GitAction::parse ──

    #[test]
    fn parse_all_valid_actions() {
        for raw in ["branch", "checkout", "commit", "merge", "push", "status", "log"] {
            let a = GitAction::parse(raw).unwrap_or_else(|e| panic!("合法 action {} 应解析成功: {}", raw, e));
            assert_eq!(a.as_str(), raw);
        }
    }

    #[test]
    fn parse_invalid_action_errors() {
        let err = GitAction::parse("rebase").unwrap_err().to_string();
        assert!(err.contains("非法 action"), "实际: {}", err);
        assert!(err.contains("rebase"));
    }

    #[test]
    fn parse_empty_action_errors() {
        let err = GitAction::parse("").unwrap_err().to_string();
        assert!(err.contains("非法 action"), "实际: {}", err);
    }

    // ── parse_params(config) ──

    #[test]
    fn params_missing_action_errors() {
        let err = parse_params(&json!({ "branch_name": "main" }))
            .unwrap_err()
            .to_string();
        assert!(err.contains("action"), "实际: {}", err);
    }

    #[test]
    fn params_minimal_valid() {
        let p = parse_params(&json!({ "action": "status" })).unwrap();
        assert_eq!(p.action, GitAction::Status);
        assert_eq!(p.branch_name, None);
        assert_eq!(p.message, None);
        assert_eq!(p.working_dir, None);
    }

    #[test]
    fn params_full_fields() {
        let p = parse_params(&json!({
            "action": "commit",
            "branch_name": "feature/x",
            "message": "fix: 修复",
            "working_dir": "/repo"
        }))
        .unwrap();
        assert_eq!(p.action, GitAction::Commit);
        assert_eq!(p.branch_name.as_deref(), Some("feature/x"));
        assert_eq!(p.message.as_deref(), Some("fix: 修复"));
        assert_eq!(p.working_dir.as_deref(), Some("/repo"));
    }

    // ── build_command ──

    #[test]
    fn command_branch_list_when_no_name() {
        let p = parse_params(&json!({ "action": "branch" })).unwrap();
        assert_eq!(build_command(&p).unwrap(), "git branch");
    }

    #[test]
    fn command_branch_create_when_name() {
        let p = parse_params(&json!({ "action": "branch", "branch_name": "feat" })).unwrap();
        assert_eq!(build_command(&p).unwrap(), "git branch feat");
    }

    #[test]
    fn command_checkout_requires_name() {
        let p = parse_params(&json!({ "action": "checkout" })).unwrap();
        let err = build_command(&p).unwrap_err().to_string();
        assert!(err.contains("branch_name"), "实际: {}", err);
    }

    #[test]
    fn command_commit_requires_message() {
        let p = parse_params(&json!({ "action": "commit" })).unwrap();
        let err = build_command(&p).unwrap_err().to_string();
        assert!(err.contains("message"), "实际: {}", err);
    }

    #[test]
    fn command_commit_quotes_message_with_space() {
        let p = parse_params(&json!({ "action": "commit", "message": "fix bug a" })).unwrap();
        let cmd = build_command(&p).unwrap();
        assert_eq!(cmd, "git commit -m \"fix bug a\"");
    }

    #[test]
    fn command_merge_requires_name() {
        let p = parse_params(&json!({ "action": "merge" })).unwrap();
        assert!(build_command(&p).is_err());
    }

    #[test]
    fn command_push_status_log_fixed() {
        for (action, expected) in [
            ("push", "git push"),
            ("status", "git status"),
            ("log", "git log --oneline -20"),
        ] {
            let p = parse_params(&json!({ "action": action })).unwrap();
            assert_eq!(build_command(&p).unwrap(), expected);
        }
    }

    // ── shell_quote ──

    #[test]
    fn shell_quote_plain_passthrough() {
        assert_eq!(shell_quote("feat"), "feat");
    }

    #[test]
    fn shell_quote_escapes_embedded_double_quote() {
        let q = shell_quote("a\"b");
        assert_eq!(q, "\"a\\\"b\"");
    }

    // ── parse_action_output ──

    #[test]
    fn parse_branch_output() {
        let out = parse_action_output(
            &GitAction::Branch,
            "* main\n  develop\n  feature/x\n",
        );
        assert_eq!(out["current"], "main");
        assert_eq!(out["branches"].as_array().unwrap().len(), 3);
    }

    #[test]
    fn parse_log_output() {
        let out = parse_action_output(
            &GitAction::Log,
            "abc1234 fix bug\n deadbeef add feature\n",
        );
        let entries = out["entries"].as_array().unwrap();
        assert_eq!(entries.len(), 2);
        assert_eq!(entries[0]["hash"], "abc1234");
        assert_eq!(entries[1]["subject"], "add feature");
    }
}