-- SPDX-FileCopyrightText: © 2022—2026 Vladimir Zorin <vladimir@deviant.guru>
-- SPDX-License-Identifier: LicenseRef-OWL-1.0-or-later
-- Licensed under OWL v1.0+. See LICENSE.

-- Manual end-to-end recipe (needs a running server):
--   ./lilush examples/git_serve.lua --dir /srv/git --port 8090 &
--   git clone http://127.0.0.1:8090/repo /tmp/clone-test
--   git -C /tmp/clone-test fsck

local testimony = require("testimony")
local std = require("std")
local http_git = require("http.git")
local crypto = require("crypto")

local testify = testimony.new("== http.git ==")

local encode_pkt = http_git.encode_pkt
local decode_pkts = http_git.decode_pkts

-- =========================================================================
-- pkt-line
-- =========================================================================

testify:that("encode_pkt: length prefix is hex of payload + 4", function()
	testimony.assert_equal("0009done\n", encode_pkt("done\n"))
	testimony.assert_equal("0004", encode_pkt(""))
end)

testify:that("decode_pkts: round-trips lines and flush", function()
	local body = encode_pkt("want abc\n") .. "0000" .. encode_pkt("done\n")
	local pkts = decode_pkts(body)
	testimony.assert_equal(3, #pkts)
	testimony.assert_equal("line", pkts[1].kind)
	testimony.assert_equal("want abc\n", pkts[1].data)
	testimony.assert_equal("flush", pkts[2].kind)
	testimony.assert_equal("done\n", pkts[3].data)
end)

testify:that("decode_pkts: rejects malformed length", function()
	local pkts, err = decode_pkts("zzzz")
	testimony.assert_nil(pkts)
	testimony.assert_match("malformed", err)
end)

testify:that("decode_pkts: rejects truncated pkt", function()
	local pkts, err = decode_pkts("00ffshort")
	testimony.assert_nil(pkts)
	testimony.assert_match("invalid pkt%-line length", err)
end)

-- =========================================================================
-- request parsing
-- =========================================================================

local SHA_A = string.rep("a", 40)
local SHA_B = string.rep("b", 40)

testify:that("parse_upload_pack_request: wants, caps, haves, done", function()
	local body = encode_pkt("want " .. SHA_A .. " side-band-64k agent=git/2.40\n")
		.. encode_pkt("want " .. SHA_B .. "\n")
		.. "0000"
		.. encode_pkt("have " .. SHA_B .. "\n")
		.. encode_pkt("done\n")
	local req = http_git.parse_upload_pack_request(body)
	testimony.assert_equal(2, #req.wants)
	testimony.assert_equal(SHA_A, req.wants[1])
	testimony.assert_true(req.side_band_64k)
	testimony.assert_false(req.side_band)
	testimony.assert_equal(1, req.haves)
	testimony.assert_true(req.done)
end)

testify:that("parse_upload_pack_request: rejects shallow/filter", function()
	local body = encode_pkt("want " .. SHA_A .. "\n") .. encode_pkt("deepen 1\n") .. "0000"
	local req, err = http_git.parse_upload_pack_request(body)
	testimony.assert_nil(req)
	testimony.assert_match("not supported", err)
end)

testify:that("parse_upload_pack_request: rejects empty request", function()
	local req, err = http_git.parse_upload_pack_request("0000")
	testimony.assert_nil(req)
	testimony.assert_match("no want lines", err)
end)

-- =========================================================================
-- Fixture-based tests (need the real git binary; skipped when absent)
-- =========================================================================

-- os.execute returns a boolean with LUA52COMPAT, a number otherwise
local sh = function(cmd)
	local r = os.execute(cmd .. " >/dev/null 2>&1")
	return r == true or r == 0
end

local has_git = sh("git --version")

local sh_out = function(cmd)
	local f = io.popen(cmd)
	if not f then
		return nil
	end
	local out = f:read("*a")
	f:close()
	return out and out:match("^%s*(.-)%s*$")
end

local make_fixture = function()
	local dir = "/tmp/" .. std.nanoid()
	local g = "git -C " .. dir .. " -c user.name=test -c user.email=test@test"
	if not sh("git init -q " .. dir) then
		return nil
	end
	std.fs.write_file(dir .. "/readme.txt", "hello lilush git serving\n")
	std.fs.mkdir(dir .. "/sub")
	std.fs.write_file(dir .. "/sub/data.bin", string.rep("\0\1\2\3", 1024))
	sh(g .. " add -A")
	sh(g .. " commit -q -m first")
	std.fs.write_file(dir .. "/readme.txt", "hello again\n")
	sh(g .. " add -A")
	sh(g .. " commit -q -m second")
	sh(g .. " tag -a v1 -m release-one")
	local head = sh_out("git -C " .. dir .. " rev-parse HEAD")
	local head_ref = sh_out("git -C " .. dir .. " symbolic-ref HEAD")
	if not head or #head ~= 40 then
		return nil
	end
	return { dir = dir, git_dir = dir .. "/.git", head = head, head_ref = head_ref }
end

local fixture = has_git and make_fixture() or nil

if fixture then
	testify:that("info_refs: valid advertisement", function()
		local advert = http_git.info_refs(fixture.git_dir)
		local pkts = decode_pkts(advert)
		testimony.assert_equal("# service=git-upload-pack\n", pkts[1].data)
		testimony.assert_equal("flush", pkts[2].kind)
		-- First ref line is HEAD with NUL-separated capabilities
		local head_line = pkts[3].data
		testimony.assert_match("^" .. fixture.head .. " HEAD\0", head_line)
		testimony.assert_match("side%-band%-64k", head_line)
		testimony.assert_match("symref=HEAD:" .. fixture.head_ref, head_line)
		testimony.assert_equal("flush", pkts[#pkts].kind)
	end)

	testify:that("upload_pack: negotiation round without done gets NAK", function()
		local body = encode_pkt("want " .. fixture.head .. "\n") .. "0000" .. encode_pkt("have " .. SHA_A .. "\n")
		testimony.assert_equal(encode_pkt("NAK\n"), http_git.upload_pack(fixture.git_dir, body))
	end)

	testify:that("upload_pack: shallow request yields ERR pkt", function()
		local body = encode_pkt("want " .. fixture.head .. "\n") .. encode_pkt("deepen 1\n") .. "0000"
		local response = http_git.upload_pack(fixture.git_dir, body)
		local pkts = decode_pkts(response)
		testimony.assert_match("^ERR ", pkts[1].data)
	end)

	testify:that("upload_pack: side-band response carries a git-valid pack", function()
		local body = encode_pkt("want " .. fixture.head .. " side-band-64k\n") .. "0000" .. encode_pkt("done\n")
		local response = http_git.upload_pack(fixture.git_dir, body)
		local pkts = decode_pkts(response)
		testimony.assert_equal("NAK\n", pkts[1].data)
		testimony.assert_equal("flush", pkts[#pkts].kind)
		local parts = {}
		for i = 2, #pkts - 1 do
			testimony.assert_equal("\1", pkts[i].data:sub(1, 1))
			parts[#parts + 1] = pkts[i].data:sub(2)
		end
		local pack = table.concat(parts)
		local pack_path = fixture.dir .. "/served.pack"
		std.fs.write_file(pack_path, pack)
		testimony.assert_true(sh("git index-pack --strict " .. pack_path))
	end)

	testify:that("upload_pack: plain (no side-band) response is NAK + raw pack", function()
		local body = encode_pkt("want " .. fixture.head .. "\n") .. "0000" .. encode_pkt("done\n")
		local response = http_git.upload_pack(fixture.git_dir, body)
		testimony.assert_equal(encode_pkt("NAK\n"), response:sub(1, 8))
		testimony.assert_equal("PACK", response:sub(9, 12))
		testimony.assert_equal(crypto.sha1(response:sub(9, -21)), response:sub(-20))
	end)

	testify:that("serve: handler routes advertisement, 404, and receive-pack refusal", function()
		local handle = http_git.serve({ ["/repo"] = fixture.dir })
		testimony.assert_not_nil(handle)

		local content, status, headers = handle("GET", "/repo/info/refs", "service=git-upload-pack", {}, nil, {})
		testimony.assert_equal(200, status)
		testimony.assert_equal("application/x-git-upload-pack-advertisement", headers["content-type"])
		testimony.assert_equal("001e# service=git-upload-pack\n", content:sub(1, 30))

		local _, dumb_status = handle("GET", "/repo/info/refs", "", {}, nil, {})
		testimony.assert_equal(403, dumb_status)

		local _, missing_status = handle("GET", "/nosuch/info/refs", "service=git-upload-pack", {}, nil, {})
		testimony.assert_equal(404, missing_status)

		local _, push_status = handle("POST", "/repo/git-receive-pack", "", {}, "", {})
		testimony.assert_equal(403, push_status)

		local body = encode_pkt("want " .. fixture.head .. "\n") .. "0000" .. encode_pkt("done\n")
		local pack_content, pack_status, pack_headers = handle("POST", "/repo/git-upload-pack", "", {}, body, {})
		testimony.assert_equal(200, pack_status)
		testimony.assert_equal("application/x-git-upload-pack-result", pack_headers["content-type"])
		testimony.assert_equal("PACK", pack_content:sub(9, 12))
	end)

	testify:that("serve: url with .git suffix resolves the same repo", function()
		local handle = http_git.serve({ ["/repo"] = fixture.dir })
		local _, status = handle("GET", "/repo.git/info/refs", "service=git-upload-pack", {}, nil, {})
		testimony.assert_equal(200, status)
	end)
else
	print("-- git binary not found (or fixture failed), skipping fixture-based tests --")
end

if fixture then
	os.execute("rm -rf " .. fixture.dir)
end
testify:conclude()