From 05368f67b663825b6c333132f8c8115e67881dcc Mon Sep 17 00:00:00 2001
From: HouXiaoxuan <Hou_Xiaoxuan@163.com>
Date: Fri, 22 Dec 2023 11:07:28 +0800
Subject: [PATCH] =?UTF-8?q?switch=E7=9A=84=E5=9F=BA=E6=9C=AC=E4=BB=A3?=
 =?UTF-8?q?=E7=A0=81=E6=A1=86=E6=9E=B6?=
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---
 src/commands/switch.rs | 90 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 79 insertions(+), 11 deletions(-)

diff --git a/src/commands/switch.rs b/src/commands/switch.rs
index 757790c..fdc6c78 100644
--- a/src/commands/switch.rs
+++ b/src/commands/switch.rs
@@ -1,16 +1,84 @@
-pub fn switch(branch: Option<String>, create: Option<String>) {
-    // TODO
+use std::path::PathBuf;
+
+use colored::Colorize;
+
+use crate::{
+    head::{self},
+    models::{commit::Commit, object::Hash},
+    store::Store,
+};
+
+use super::{
+    branch,
+    restore::{restore_staged_into_files, restore_workdir_into_files},
+    status::{changes_to_be_committed, changes_to_be_staged},
+};
+
+enum SwitchErr {
+    NoClean,
+    InvalidBranch,
+    InvalidObject,
+}
+
+/** 将工作区域的文件更改为commit_hash的版本，可以指定filter未特定文件或路径 */
+fn switch_to_commit(filter: Option<PathBuf>, commit_hash: Hash) {
+    let commit = Commit::load(&commit_hash);
+    let tree = commit.get_tree();
+    let target_files = tree.get_recursive_blobs(); // 相对路径
+
+    // 借用逻辑类似的restore_workdir_into_files
+    restore_workdir_into_files(filter.clone(), target_files.clone());
+    // 同时restore index
+    restore_staged_into_files(filter, target_files);
+}
+
+fn switch_to(branch: String, detach: bool) -> Result<(), SwitchErr> {
+    // 检查更改
+    if !changes_to_be_staged().is_empty() {
+        println!("fatal: 你有未暂存的更改，切换分支会导致更改丢失");
+        return Err(SwitchErr::NoClean);
+    } else if !changes_to_be_committed().is_empty() {
+        println!("fatal: 你有未提交的更改，无法切换分支");
+        return Err(SwitchErr::NoClean);
+    }
+
+    let store = Store::new();
+    if head::list_local_branches().contains(&branch) {
+        // 切到分支
+        let branch_commit = head::get_branch_head(&branch);
+        switch_to_commit(None, branch_commit.clone());
+        head::change_head_to_branch(&branch); // 更改head
+        println!("切换到分支： '{}'", branch.green())
+    } else if detach {
+        let commit = store.search(&branch);
+        if commit.is_none() {
+            println!("fatal: 非法的 commit: '{}'", branch);
+            return Err(SwitchErr::InvalidObject);
+        }
+        // 切到commit
+        let commit = commit.unwrap();
+        switch_to_commit(None, commit.clone());
+        head::change_head_to_commit(&commit); // 更改head
+        println!("切换到 detach commit： '{}'", commit.yellow())
+    } else {
+        println!("fatal: 不存在分支 '{}'", branch);
+        return Err(SwitchErr::InvalidBranch);
+    }
+
+    Ok(())
+}
+
+pub fn switch(target_branch: Option<String>, create: Option<String>, detach: bool) {
     match create {
-        Some(branch_name) => match branch {
-            Some(branch) => {
-                println!("craete and switch to branch: {:?} base on {:?}", branch_name, branch);
-            }
-            None => {
-                println!("create and switch to branch: {:?}", branch_name);
-            }
-        },
+        Some(new_branch) => {
+            // 以target_branch为基础创建新分支create
+            println!("create new branch: {:?}", new_branch);
+            branch::branch(Some(new_branch.clone()), target_branch.clone(), false, None, false);
+            let _ = switch_to(new_branch, true);
+        }
         None => {
-            println!("switch to branch: {:?}", branch.unwrap());
+            println!("switch to branch: {:?}", target_branch.as_ref().unwrap());
+            let _ = switch_to(target_branch.unwrap(), detach);
         }
     }
 }