Initial commit: MVP

6 files changed, 596 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9a1e412
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+venv/
+.vscode/
+__pycache__/
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..89e08fb
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,339 @@
+                    GNU GENERAL PUBLIC LICENSE

+                       Version 2, June 1991

+

+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,

+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ Everyone is permitted to copy and distribute verbatim copies

+ of this license document, but changing it is not allowed.

+

+                            Preamble

+

+  The licenses for most software are designed to take away your

+freedom to share and change it.  By contrast, the GNU General Public

+License is intended to guarantee your freedom to share and change free

+software--to make sure the software is free for all its users.  This

+General Public License applies to most of the Free Software

+Foundation's software and to any other program whose authors commit to

+using it.  (Some other Free Software Foundation software is covered by

+the GNU Lesser General Public License instead.)  You can apply it to

+your programs, too.

+

+  When we speak of free software, we are referring to freedom, not

+price.  Our General Public Licenses are designed to make sure that you

+have the freedom to distribute copies of free software (and charge for

+this service if you wish), that you receive source code or can get it

+if you want it, that you can change the software or use pieces of it

+in new free programs; and that you know you can do these things.

+

+  To protect your rights, we need to make restrictions that forbid

+anyone to deny you these rights or to ask you to surrender the rights.

+These restrictions translate to certain responsibilities for you if you

+distribute copies of the software, or if you modify it.

+

+  For example, if you distribute copies of such a program, whether

+gratis or for a fee, you must give the recipients all the rights that

+you have.  You must make sure that they, too, receive or can get the

+source code.  And you must show them these terms so they know their

+rights.

+

+  We protect your rights with two steps: (1) copyright the software, and

+(2) offer you this license which gives you legal permission to copy,

+distribute and/or modify the software.

+

+  Also, for each author's protection and ours, we want to make certain

+that everyone understands that there is no warranty for this free

+software.  If the software is modified by someone else and passed on, we

+want its recipients to know that what they have is not the original, so

+that any problems introduced by others will not reflect on the original

+authors' reputations.

+

+  Finally, any free program is threatened constantly by software

+patents.  We wish to avoid the danger that redistributors of a free

+program will individually obtain patent licenses, in effect making the

+program proprietary.  To prevent this, we have made it clear that any

+patent must be licensed for everyone's free use or not licensed at all.

+

+  The precise terms and conditions for copying, distribution and

+modification follow.

+

+                    GNU GENERAL PUBLIC LICENSE

+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

+

+  0. This License applies to any program or other work which contains

+a notice placed by the copyright holder saying it may be distributed

+under the terms of this General Public License.  The "Program", below,

+refers to any such program or work, and a "work based on the Program"

+means either the Program or any derivative work under copyright law:

+that is to say, a work containing the Program or a portion of it,

+either verbatim or with modifications and/or translated into another

+language.  (Hereinafter, translation is included without limitation in

+the term "modification".)  Each licensee is addressed as "you".

+

+Activities other than copying, distribution and modification are not

+covered by this License; they are outside its scope.  The act of

+running the Program is not restricted, and the output from the Program

+is covered only if its contents constitute a work based on the

+Program (independent of having been made by running the Program).

+Whether that is true depends on what the Program does.

+

+  1. You may copy and distribute verbatim copies of the Program's

+source code as you receive it, in any medium, provided that you

+conspicuously and appropriately publish on each copy an appropriate

+copyright notice and disclaimer of warranty; keep intact all the

+notices that refer to this License and to the absence of any warranty;

+and give any other recipients of the Program a copy of this License

+along with the Program.

+

+You may charge a fee for the physical act of transferring a copy, and

+you may at your option offer warranty protection in exchange for a fee.

+

+  2. You may modify your copy or copies of the Program or any portion

+of it, thus forming a work based on the Program, and copy and

+distribute such modifications or work under the terms of Section 1

+above, provided that you also meet all of these conditions:

+

+    a) You must cause the modified files to carry prominent notices

+    stating that you changed the files and the date of any change.

+

+    b) You must cause any work that you distribute or publish, that in

+    whole or in part contains or is derived from the Program or any

+    part thereof, to be licensed as a whole at no charge to all third

+    parties under the terms of this License.

+

+    c) If the modified program normally reads commands interactively

+    when run, you must cause it, when started running for such

+    interactive use in the most ordinary way, to print or display an

+    announcement including an appropriate copyright notice and a

+    notice that there is no warranty (or else, saying that you provide

+    a warranty) and that users may redistribute the program under

+    these conditions, and telling the user how to view a copy of this

+    License.  (Exception: if the Program itself is interactive but

+    does not normally print such an announcement, your work based on

+    the Program is not required to print an announcement.)

+

+These requirements apply to the modified work as a whole.  If

+identifiable sections of that work are not derived from the Program,

+and can be reasonably considered independent and separate works in

+themselves, then this License, and its terms, do not apply to those

+sections when you distribute them as separate works.  But when you

+distribute the same sections as part of a whole which is a work based

+on the Program, the distribution of the whole must be on the terms of

+this License, whose permissions for other licensees extend to the

+entire whole, and thus to each and every part regardless of who wrote it.

+

+Thus, it is not the intent of this section to claim rights or contest

+your rights to work written entirely by you; rather, the intent is to

+exercise the right to control the distribution of derivative or

+collective works based on the Program.

+

+In addition, mere aggregation of another work not based on the Program

+with the Program (or with a work based on the Program) on a volume of

+a storage or distribution medium does not bring the other work under

+the scope of this License.

+

+  3. You may copy and distribute the Program (or a work based on it,

+under Section 2) in object code or executable form under the terms of

+Sections 1 and 2 above provided that you also do one of the following:

+

+    a) Accompany it with the complete corresponding machine-readable

+    source code, which must be distributed under the terms of Sections

+    1 and 2 above on a medium customarily used for software interchange; or,

+

+    b) Accompany it with a written offer, valid for at least three

+    years, to give any third party, for a charge no more than your

+    cost of physically performing source distribution, a complete

+    machine-readable copy of the corresponding source code, to be

+    distributed under the terms of Sections 1 and 2 above on a medium

+    customarily used for software interchange; or,

+

+    c) Accompany it with the information you received as to the offer

+    to distribute corresponding source code.  (This alternative is

+    allowed only for noncommercial distribution and only if you

+    received the program in object code or executable form with such

+    an offer, in accord with Subsection b above.)

+

+The source code for a work means the preferred form of the work for

+making modifications to it.  For an executable work, complete source

+code means all the source code for all modules it contains, plus any

+associated interface definition files, plus the scripts used to

+control compilation and installation of the executable.  However, as a

+special exception, the source code distributed need not include

+anything that is normally distributed (in either source or binary

+form) with the major components (compiler, kernel, and so on) of the

+operating system on which the executable runs, unless that component

+itself accompanies the executable.

+

+If distribution of executable or object code is made by offering

+access to copy from a designated place, then offering equivalent

+access to copy the source code from the same place counts as

+distribution of the source code, even though third parties are not

+compelled to copy the source along with the object code.

+

+  4. You may not copy, modify, sublicense, or distribute the Program

+except as expressly provided under this License.  Any attempt

+otherwise to copy, modify, sublicense or distribute the Program is

+void, and will automatically terminate your rights under this License.

+However, parties who have received copies, or rights, from you under

+this License will not have their licenses terminated so long as such

+parties remain in full compliance.

+

+  5. You are not required to accept this License, since you have not

+signed it.  However, nothing else grants you permission to modify or

+distribute the Program or its derivative works.  These actions are

+prohibited by law if you do not accept this License.  Therefore, by

+modifying or distributing the Program (or any work based on the

+Program), you indicate your acceptance of this License to do so, and

+all its terms and conditions for copying, distributing or modifying

+the Program or works based on it.

+

+  6. Each time you redistribute the Program (or any work based on the

+Program), the recipient automatically receives a license from the

+original licensor to copy, distribute or modify the Program subject to

+these terms and conditions.  You may not impose any further

+restrictions on the recipients' exercise of the rights granted herein.

+You are not responsible for enforcing compliance by third parties to

+this License.

+

+  7. If, as a consequence of a court judgment or allegation of patent

+infringement or for any other reason (not limited to patent issues),

+conditions are imposed on you (whether by court order, agreement or

+otherwise) that contradict the conditions of this License, they do not

+excuse you from the conditions of this License.  If you cannot

+distribute so as to satisfy simultaneously your obligations under this

+License and any other pertinent obligations, then as a consequence you

+may not distribute the Program at all.  For example, if a patent

+license would not permit royalty-free redistribution of the Program by

+all those who receive copies directly or indirectly through you, then

+the only way you could satisfy both it and this License would be to

+refrain entirely from distribution of the Program.

+

+If any portion of this section is held invalid or unenforceable under

+any particular circumstance, the balance of the section is intended to

+apply and the section as a whole is intended to apply in other

+circumstances.

+

+It is not the purpose of this section to induce you to infringe any

+patents or other property right claims or to contest validity of any

+such claims; this section has the sole purpose of protecting the

+integrity of the free software distribution system, which is

+implemented by public license practices.  Many people have made

+generous contributions to the wide range of software distributed

+through that system in reliance on consistent application of that

+system; it is up to the author/donor to decide if he or she is willing

+to distribute software through any other system and a licensee cannot

+impose that choice.

+

+This section is intended to make thoroughly clear what is believed to

+be a consequence of the rest of this License.

+

+  8. If the distribution and/or use of the Program is restricted in

+certain countries either by patents or by copyrighted interfaces, the

+original copyright holder who places the Program under this License

+may add an explicit geographical distribution limitation excluding

+those countries, so that distribution is permitted only in or among

+countries not thus excluded.  In such case, this License incorporates

+the limitation as if written in the body of this License.

+

+  9. The Free Software Foundation may publish revised and/or new versions

+of the General Public License from time to time.  Such new versions will

+be similar in spirit to the present version, but may differ in detail to

+address new problems or concerns.

+

+Each version is given a distinguishing version number.  If the Program

+specifies a version number of this License which applies to it and "any

+later version", you have the option of following the terms and conditions

+either of that version or of any later version published by the Free

+Software Foundation.  If the Program does not specify a version number of

+this License, you may choose any version ever published by the Free Software

+Foundation.

+

+  10. If you wish to incorporate parts of the Program into other free

+programs whose distribution conditions are different, write to the author

+to ask for permission.  For software which is copyrighted by the Free

+Software Foundation, write to the Free Software Foundation; we sometimes

+make exceptions for this.  Our decision will be guided by the two goals

+of preserving the free status of all derivatives of our free software and

+of promoting the sharing and reuse of software generally.

+

+                            NO WARRANTY

+

+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY

+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN

+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES

+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED

+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS

+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE

+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,

+REPAIR OR CORRECTION.

+

+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING

+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR

+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,

+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING

+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED

+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY

+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER

+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE

+POSSIBILITY OF SUCH DAMAGES.

+

+                     END OF TERMS AND CONDITIONS

+

+            How to Apply These Terms to Your New Programs

+

+  If you develop a new program, and you want it to be of the greatest

+possible use to the public, the best way to achieve this is to make it

+free software which everyone can redistribute and change under these terms.

+

+  To do so, attach the following notices to the program.  It is safest

+to attach them to the start of each source file to most effectively

+convey the exclusion of warranty; and each file should have at least

+the "copyright" line and a pointer to where the full notice is found.

+

+    <one line to give the program's name and a brief idea of what it does.>

+    Copyright (C) <year>  <name of author>

+

+    This program is free software; you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation; either version 2 of the License, or

+    (at your option) any later version.

+

+    This program is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+    GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License along

+    with this program; if not, write to the Free Software Foundation, Inc.,

+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

+

+Also add information on how to contact you by electronic and paper mail.

+

+If the program is interactive, make it output a short notice like this

+when it starts in an interactive mode:

+

+    Gnomovision version 69, Copyright (C) year name of author

+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.

+    This is free software, and you are welcome to redistribute it

+    under certain conditions; type `show c' for details.

+

+The hypothetical commands `show w' and `show c' should show the appropriate

+parts of the General Public License.  Of course, the commands you use may

+be called something other than `show w' and `show c'; they could even be

+mouse-clicks or menu items--whatever suits your program.

+

+You should also get your employer (if you work as a programmer) or your

+school, if any, to sign a "copyright disclaimer" for the program, if

+necessary.  Here is a sample; alter the names:

+

+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program

+  `Gnomovision' (which makes passes at compilers) written by James Hacker.

+

+  <signature of Ty Coon>, 1 April 1989

+  Ty Coon, President of Vice

+

+This General Public License does not permit incorporating your program into

+proprietary programs.  If your program is a subroutine library, you may

+consider it more useful to permit linking proprietary applications with the

+library.  If this is what you want to do, use the GNU Lesser General

+Public License instead of this License.

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a339f2a
--- /dev/null
+++ b/README.md
@@ -0,0 +1,15 @@
+# git.gmi - git frontend CGI script
+
+## Front Matter
+
+You may find it strange how I wrote a CGI script when there are so many amazing things available, and you're right. Git.gmi isn't meant to be a CGI script; it _had_ to be one. The only Gemini server library I know in Python, [Jetforce](https://github.com/michael-lazar/jetforce), is licensed under the [Floodgap "Free" Software License](https://www.floodgap.com/software/ffsl/), which is free software but well, free as in beer. I find absolutely no reason to allow proprietization but prohibit monetization, which is the _exact opposite_ from the GPL - unfortunately the license of choice by the `pygit2` devs. So here we are, locked in restrictions of both fundamental dependencies that don't get along with each other. I once comtemplated violating FFSL, before coming up with this workaround, i.e. CGI. Git.gmi is licensed under GPLv2 eventually.
+
+The CGI script, `cgi.py`, prints output to stdout as response to the user, the one thing I'm uncomfortable with because it disables the One True Debugger. As an extra workaround, I just used `raise Exception('debug message')` everywhere (but deleted all of them before committing, ofc).
+
+It's in the MVP stage, with the ability to view summary, trees, blobs, and commit log in a primitive way. There is a test instance at `gemini://fkfd.me/git/cgi.py/`.
+
+## Usage
+
+TODO
+
+You need to edit the shebang of `cgi.py`.
diff --git a/git-gmi/cgi.py b/git-gmi/cgi.py
new file mode 100755
index 0000000..c243ccd
--- /dev/null
+++ b/git-gmi/cgi.py
@@ -0,0 +1,77 @@
+#!/home/fakefred/p/git.gmi/venv/bin/python3.8
+# gotta change the executable path before running
+from git import *
+from const import *
+from os import environ, listdir
+
+# be careful when using print(); stdout is passed to the client.
+# this cgi uses \n as newline.
+
+
+def generate_navigation(repo_name: str):
+    pass  # TODO
+
+
+def handle_cgi_request(path: str):
+    # intended to work with Jetforce.
+    # url: gemini://git.gemini.site/cgi-bin/cgi.py/repo/src/static/css/[index.css]
+    # path: /repo/src/static/css/[index.css]
+    # path_trace = ['repo', 'src', 'static', 'css', 'index.css']
+    path_trace = path[1:].split("/")
+    if path_trace == [""]:  # empty path
+        print(f"{STATUS_SUCCESS} {META_GEMINI}")  # welcome page
+        print("Welcome to the git.gmi demo")
+        print("Available repositories:")
+        print("\n".join([f"=> {dir}/summary" for dir in listdir(GIT_CATALOG)]))
+        return
+
+    try:
+        repo = GitGmiRepo(path_trace[0], f"{GIT_CATALOG}/{path_trace[0]}")
+    except FileNotFoundError:
+        print(STATUS_NOT_FOUND)
+        return
+
+    if len(path_trace) > 1:
+        view = path_trace[1]  # e.g. summary, tree, log
+    else:
+        pass  # TODO: summary
+
+    if view == "summary":
+        try:
+            print(repo.view_summary())
+            return
+        except:
+            print(STATUS_TEMPORARY_FAILURE)
+            return
+
+    elif view == "tree":
+        if len(path_trace) == 2:
+            print("31 master/")
+            return
+
+        if len(path_trace) > 2:
+            branch = path_trace[2]
+
+        if len(path_trace) == 3:
+            location = []
+        else:
+            location = path_trace[3:]
+
+        try:  # is dir
+            print(repo.view_tree(branch, location))
+        except FileNotFoundError:  # is file
+            try:
+                print(repo.view_blob(branch, location))
+            except FileNotFoundError:
+                print("50 Error locating content")
+
+    elif view == "log":
+        try:
+            print(repo.view_log())
+            return
+        except:
+            print(STATUS_TEMPORARY_FAILURE)
+            return
+
+
+handle_cgi_request(environ.get("PATH_INFO"))
diff --git a/git-gmi/const.py b/git-gmi/const.py
new file mode 100644
index 0000000..9a1bddd
--- /dev/null
+++ b/git-gmi/const.py
@@ -0,0 +1,5 @@
+GIT_CATALOG = "/home/fakefred/p/gemini/git/"
+STATUS_SUCCESS = "20 SUCCESS"
+STATUS_NOT_FOUND = "51 NOT FOUND"
+STATUS_TEMPORARY_FAILURE = "40 TEMPORARY FAILURE"
+META_GEMINI = "text/gemini"
diff --git a/git-gmi/git.py b/git-gmi/git.py
new file mode 100644
index 0000000..9a0ab0d
--- /dev/null
+++ b/git-gmi/git.py
@@ -0,0 +1,157 @@
+from pygit2 import *
+import mimetypes
+from const import *
+
+
+class GitGmiRepo:
+    def __init__(self, name: str, path: str):
+        self.name = name
+        self.path = path
+        try:
+            self.repo = Repository(path)
+        except FileNotFoundError:
+            print(f"Error: repository {path} not found")
+
+    def view_summary(self) -> str:
+        tree = self.get_tree("master")
+        trls = self.list_tree(tree)
+        for item in trls:
+            if item["type"] == "file" and item["name"].lower().split(".")[0] == (
+                "readme"
+            ):
+                # mimetypes.guess_type() returns tuple (type, encoding)
+                # only the first one of which we care about
+                response = (
+                    f"{STATUS_SUCCESS} {mimetypes.guess_type(item['name'])[0]}\n"
+                    "=> tree/master/ tree\n"
+                    "=> log/ log\n\n"
+                )
+                response += item["blob"].data.decode("utf-8")
+                break
+        return response
+
+    def get_commit_log(self) -> list:
+        # returns the commit log in a human-readable way.
+        repo = self.repo
+        commits = list(repo.walk(repo[repo.head.target].id, GIT_SORT_TIME))
+        log = [
+            {
+                "id": str(cmt.id),  # hex SHA-1 hash
+                "short_id": str(cmt.short_id),  # short version of the above
+                "author": cmt.author.name,  # author's display name
+                "time": cmt.commit_time,  # unix timestamp
+                "msg": cmt.message,  # full commit message
+            }
+            for cmt in commits
+        ]
+
+        return log  # reverse chronical order
+
+    def view_log(self) -> str:
+        response = f"{STATUS_SUCCESS} {META_GEMINI}\n"
+        log = self.get_commit_log()
+        for cmt in log:
+            response += f"## {cmt['short_id']} - {cmt['author']}\n{cmt['msg']}\n\n"
+        return response
+
+    @classmethod
+    def parse_recursive_tree(cls, tree: Tree) -> list:
+        # recursively replace all Trees with a list of Blobs inside it,
+        # bundled with the Tree's name as a tuple,
+        # e.g. [('src', [blob0, blob1]), otherblob].
+        tree_list = list(tree)
+        for idx, item in enumerate(tree_list):
+            if isinstance(item, Tree):
+                tree_list[idx] = (item.name, cls.parse_recursive_tree(tree_list[idx]))
+
+        return tree_list
+
+    def get_tree(self, commit_str: str) -> list:
+        # returns a recursive list of Blob objects
+        try:
+            commit = self.repo.revparse_single(commit_str)
+            # top level tree; may contain sub-trees
+            return self.parse_recursive_tree(commit.tree)
+        except ValueError:
+            raise FileNotFoundError(f"Error: no such tree: {commit_str}")
+            return None
+
+    @staticmethod
+    def list_tree(tree_list: list, location=[]) -> list:
+        # tree_list is the output of parse_recursive_tree(<tree>);
+        # location is which dir you are viewing, represented path-like
+        # in a list, e.g. ['src', 'static', 'css'] => 'src/static/css',
+        # which this method will cd into and display to the visitor.
+        # when there is no such dir, raises FileNotFoundError.
+        trls = tree_list
+        for loc in location:
+            found = False
+            for item in trls:
+                if isinstance(item, tuple) and item[0] == loc:
+                    trls = item[1]
+                    found = True
+                    break
+            if not found:
+                raise FileNotFoundError(
+                    f"Error: no such directory: {'/'.join(location)}"
+                )
+
+        contents = []
+        for item in trls:
+            if isinstance(item, tuple):
+                # was originally a Tree; structure: ('dir_name', [list_of_blobs])
+                contents.append(
+                    {
+                        "type": "dir",
+                        "name": item[0],
+                        "size": len(item[1]),  # number of objects in dir
+                    }
+                )
+
+            elif isinstance(item, Blob):
+                contents.append(
+                    {
+                        "type": "file",
+                        "name": item.name,
+                        "blob": item,
+                        "size": item.size,  # size in bytes
+                    }
+                )
+
+        return contents
+
+    def view_tree(self, branch: str, location=[]) -> str:
+        # actual Gemini response
+        # consists of a header and a body
+        response = f"{STATUS_SUCCESS} {META_GEMINI}\n"
+        tree = self.get_tree(branch)
+        contents = self.list_tree(tree, location)
+        for item in contents:
+            if item["type"] == "dir":
+                response += (
+                    f"=> {item['name']}/ {item['name']}/ | {item['size']} items\n"
+                )
+            elif item["type"] == "file":
+                response += f"=> {item['name']} {item['name']} | {item['size']} bytes\n"
+        return response
+
+    def get_blob(self, commit_str: str, location=[]) -> Blob:
+        # returns a specific Blob object
+        # location: just like that of list_tree, but the last element
+        # is the filename
+        try:
+            tree = self.get_tree(commit_str)
+            trls = self.list_tree(tree, location[:-1])
+            for item in trls:
+                if item["type"] == "file" and item["name"] == location[-1]:
+                    return item["blob"]
+            raise FileNotFoundError(f"Error: no such file: {'/'.join(location)}")
+        except FileNotFoundError:
+            raise FileNotFoundError(f"Error: No such tree: {'/'.join(location[:-1])}")
+
+    def view_blob(self, branch: str, location=[]) -> str:
+        blob = self.get_blob(branch, location)
+        guessed_mimetype = mimetypes.guess_type(blob.name)[0] or "text/plain"
+        response = f"{STATUS_SUCCESS} {guessed_mimetype}\n"
+        response += blob.data.decode("utf-8")
+        return response