local cmd = require("git.cmd")
local h = require("test.git.helpers")
local t = require("test")

require("git").init()

---@param files table<string, string>?
---@return string dir
local function make_repo(files)
    return h.make_repo(files, { cd = true })
end

---@param actual string[]
---@param expected string[]
local function eq_sorted(actual, expected, msg)
    table.sort(actual)
    table.sort(expected)
    t.eq(actual, expected, msg)
end

t.test("parse_args splits on whitespace", function()
    t.eq(
        cmd.parse_args("config user.name value"),
        { "config", "user.name", "value" }
    )
end)

t.test("parse_args preserves spaces inside double quotes", function()
    t.eq(
        cmd.parse_args([[config user.name "Oscar Wallberg"]]),
        { "config", "user.name", "Oscar Wallberg" }
    )
end)

t.test("parse_args preserves spaces inside single quotes", function()
    t.eq(
        cmd.parse_args([[log --grep='bug fix' --author=Oscar]]),
        { "log", "--grep=bug fix", "--author=Oscar" }
    )
end)

t.test("parse_args handles backslash-escaped space", function()
    t.eq(cmd.parse_args([[a\ b c]]), { "a b", "c" })
end)

t.test("parse_args handles escaped quote inside double quotes", function()
    t.eq(cmd.parse_args([["a\"b" c]]), { 'a"b', "c" })
end)

t.test("parse_args treats backslash literally inside single quotes", function()
    t.eq(cmd.parse_args([['a\b' c]]), { "a\\b", "c" })
end)

t.test("parse_args concatenates adjacent quoted segments", function()
    t.eq(cmd.parse_args([[foo"bar"baz]]), { "foobarbaz" })
end)

t.test("parse_args handles tabs as separators", function()
    t.eq(cmd.parse_args("a\tb\tc"), { "a", "b", "c" })
end)

t.test("parse_args returns empty list for empty or whitespace input", function()
    t.eq(cmd.parse_args(""), {})
    t.eq(cmd.parse_args("   \t  "), {})
end)

t.test("parse_args preserves empty quoted token", function()
    t.eq(cmd.parse_args([[a "" b]]), { "a", "", "b" })
end)

t.test("parse_args expands %% on unquoted token", function()
    local buf = vim.api.nvim_create_buf(false, false)
    t.defer(function()
        pcall(vim.api.nvim_buf_delete, buf, { force = true })
    end)
    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
    vim.api.nvim_set_current_buf(buf)

    t.eq(
        cmd.parse_args("add %"),
        { "add", vim.fn.getcwd() .. "/some-file.lua" }
    )
end)

t.test("parse_args does not expand %% inside double quotes", function()
    local buf = vim.api.nvim_create_buf(false, false)
    t.defer(function()
        pcall(vim.api.nvim_buf_delete, buf, { force = true })
    end)
    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
    vim.api.nvim_set_current_buf(buf)

    t.eq(cmd.parse_args([[log -- "%"]]), { "log", "--", "%" })
end)

t.test("parse_args does not expand %% inside single quotes", function()
    local buf = vim.api.nvim_create_buf(false, false)
    t.defer(function()
        pcall(vim.api.nvim_buf_delete, buf, { force = true })
    end)
    vim.api.nvim_buf_set_name(buf, vim.fn.getcwd() .. "/some-file.lua")
    vim.api.nvim_set_current_buf(buf)

    t.eq(cmd.parse_args([[log -- '%']]), { "log", "--", "%" })
end)

t.test("parse_args does not treat mid-token tilde as expansion", function()
    t.eq(cmd.parse_args("checkout HEAD~3"), { "checkout", "HEAD~3" })
end)

t.test("parse_args expands leading ~/ to home", function()
    t.eq(cmd.parse_args("add ~/foo"), { "add", vim.fn.expand("~/foo") })
end)

t.test("parse_complete_state with trailing space", function()
    local s = cmd._parse_complete_state("G push origin ")
    t.eq(s.prior, { "push", "origin" })
    t.falsy(s.after_separator)
end)

t.test("parse_complete_state mid-token", function()
    local s = cmd._parse_complete_state("G push or")
    t.eq(s.prior, { "push" })
    t.falsy(s.after_separator)
end)

t.test("parse_complete_state empty after command", function()
    local s = cmd._parse_complete_state("G ")
    t.eq(s.prior, {})
    t.falsy(s.after_separator)
end)

t.test("parse_complete_state detects -- separator", function()
    local s = cmd._parse_complete_state("G log -- foo")
    t.eq(s.prior, { "log", "--" })
    t.truthy(s.after_separator)
end)

t.test("positional_index ignores flags", function()
    t.eq(cmd._positional_index({ "push" }), 1)
    t.eq(cmd._positional_index({ "push", "origin" }), 2)
    t.eq(cmd._positional_index({ "push", "--force" }), 1)
    t.eq(cmd._positional_index({ "push", "--force", "origin" }), 2)
    t.eq(cmd._positional_index({ "checkout", "-b", "feature" }), 2)
end)

t.test("complete returns subcommands at first position", function()
    local matches = cmd.complete("ch", "G ch", 4)
    t.truthy(vim.tbl_contains(matches, "checkout"))
    t.truthy(vim.tbl_contains(matches, "cherry-pick"))
end)

t.test("complete returns flags when arg starts with -", function()
    local matches = cmd.complete("--am", "G commit --am", 13)
    t.eq(matches, { "--amend" })
end)

t.test("complete branch returns plain refs (no pseudo, no stash)", function()
    local dir = make_repo({ a = "x" })
    h.git(dir, "branch", "feature")
    h.git(dir, "tag", "v1")
    t.write(dir, "a", "modified")
    h.git(dir, "stash")
    local matches = cmd.complete("", "G branch ", 9)
    eq_sorted(matches, { "feature", "main", "v1" })
end)

t.test("complete merge returns refs + pseudo + stash", function()
    local dir = make_repo({ a = "x" })
    h.git(dir, "branch", "feature")
    t.write(dir, "a", "y")
    h.git(dir, "stash")
    local matches = cmd.complete("", "G merge ", 8)
    eq_sorted(
        matches,
        { "HEAD", "ORIG_HEAD", "feature", "main", "stash", "stash@{0}" }
    )
end)

t.test("complete push first positional returns remotes", function()
    local dir = make_repo({ a = "x" })
    h.git(dir, "remote", "add", "origin", "/tmp/nope")
    h.git(dir, "remote", "add", "upstream", "/tmp/nope")
    local matches = cmd.complete("", "G push ", 7)
    eq_sorted(matches, { "origin", "upstream" })
end)

t.test("complete push second positional returns refs", function()
    local dir = make_repo({ a = "x" })
    h.git(dir, "branch", "feature")
    local matches = cmd.complete("", "G push origin ", 14)
    eq_sorted(matches, { "HEAD", "feature", "main" })
end)

t.test("complete add returns only unstaged/untracked paths", function()
    local dir = make_repo({ tracked = "x" })
    t.write(dir, "tracked", "modified")
    t.write(dir, "newfile", "new")
    local r = assert(require("git.repo").resolve(dir))
    r:refresh()
    t.wait_for(function()
        return r.status and #vim.tbl_keys(r.status.entries) > 0
    end, "git status to report entries", 500)
    local matches = cmd.complete("", "G add ", 6)
    eq_sorted(matches, { "newfile", "tracked" })
end)

t.test("complete after `--` returns tracked paths only", function()
    local dir = make_repo({ a = "x", b = "y" })
    t.write(dir, "untracked", "z")
    local matches = cmd.complete("", "G log -- ", 9)
    eq_sorted(matches, { "a", "b" })
end)

t.test("complete stash returns subsubcommands", function()
    make_repo({ a = "x" })
    local matches = cmd.complete("p", "G stash p", 9)
    eq_sorted(matches, { "pop", "push" })
end)

t.test("complete show with <rev>:<path> returns tree paths", function()
    make_repo({ a = "x", ["sub/b"] = "y" })
    local matches = cmd.complete("HEAD:", "G show HEAD:", 12)
    eq_sorted(matches, { "HEAD:a", "HEAD:sub/" })
end)

t.test("complete unknown subcommand falls back to tracked paths", function()
    make_repo({ a = "x", b = "y" })
    local matches = cmd.complete("", "G nonexistent ", 14)
    eq_sorted(matches, { "a", "b" })
end)

---@param name_pattern string
---@return integer count
local function count_bufs_named(name_pattern)
    local n = 0
    for _, b in ipairs(vim.api.nvim_list_bufs()) do
        if vim.api.nvim_buf_get_name(b):match(name_pattern) then
            n = n + 1
        end
    end
    return n
end

---@param buf_name_pattern string
---@param timeout integer?
local function wait_buf_populated(buf_name_pattern, timeout)
    t.wait_for(function()
        for _, b in ipairs(vim.api.nvim_list_bufs()) do
            if vim.api.nvim_buf_get_name(b):match(buf_name_pattern) then
                return #vim.api.nvim_buf_get_lines(b, 0, -1, false) > 1
            end
        end
        return false
    end, "buffer matching " .. buf_name_pattern .. " to populate", timeout)
end

---Wait for a buffer matching `buf_name_pattern` to contain a line whose
---content equals `line`. Useful for asserting that re-running a :G
---command repopulated the buffer with new output.
---@param buf_name_pattern string
---@param line string
---@param timeout integer?
local function wait_buf_has_line(buf_name_pattern, line, timeout)
    t.wait_for(function()
        for _, b in ipairs(vim.api.nvim_list_bufs()) do
            if vim.api.nvim_buf_get_name(b):match(buf_name_pattern) then
                for _, l in ipairs(vim.api.nvim_buf_get_lines(b, 0, -1, false)) do
                    if l == line then
                        return true
                    end
                end
            end
        end
        return false
    end, "buffer " .. buf_name_pattern .. " to contain " .. line, timeout)
end

t.test("run :G diff reuses the same buffer across invocations", function()
    local dir = make_repo({ a = "v1\n" })
    t.write(dir, "a", "v2\n")

    cmd.run({ "diff" })
    wait_buf_has_line("%[Git diff%]", "+v2")
    t.eq(count_bufs_named("%[Git diff%]"), 1)

    t.write(dir, "a", "v3\n")
    cmd.run({ "diff" })
    wait_buf_has_line("%[Git diff%]", "+v3")
    t.eq(count_bufs_named("%[Git diff%]"), 1, "second :G diff should reuse")

    t.write(dir, "a", "v4\n")
    cmd.run({ "diff" })
    wait_buf_has_line("%[Git diff%]", "+v4")
    t.eq(count_bufs_named("%[Git diff%]"), 1, "third :G diff should reuse")
end)

---@param buf integer
---@param prefix string
---@return integer? lnum
local function find_line(buf, prefix)
    for i, l in ipairs(vim.api.nvim_buf_get_lines(buf, 0, -1, false)) do
        if l:sub(1, #prefix) == prefix then
            return i
        end
    end
end

t.test(":G show <CR> on + line opens the blob URI", function()
    local dir = make_repo({ a = "first\n" })
    t.write(dir, "a", "second\n")
    h.git(dir, "add", "a")
    h.git(dir, "commit", "-q", "-m", "second")
    assert(require("git.repo").resolve(dir))
    local blob = h.git(dir, "rev-parse", "HEAD:a").stdout

    cmd.run({ "show", "HEAD" })
    wait_buf_populated("%[Git show HEAD%]")
    ---@type integer?
    local diff_buf
    for _, b in ipairs(vim.api.nvim_list_bufs()) do
        if vim.api.nvim_buf_get_name(b):match("%[Git show HEAD%]") then
            diff_buf = b
        end
    end
    assert(diff_buf, "expected [Git show HEAD] buffer")
    local win = vim.fn.bufwinid(diff_buf)
    vim.api.nvim_set_current_win(win)
    local lnum = assert(find_line(diff_buf, "+second"))
    vim.api.nvim_win_set_cursor(win, { lnum, 0 })

    t.truthy(require("git.object").open_under_cursor())
    t.eq(vim.api.nvim_buf_get_name(0), "git://" .. blob)
end)

t.test("<leader>gl log buffer refills after jumping back", function()
    local dir = make_repo({ a = "v1\n" })
    t.write(dir, "a", "v2\n")
    h.git(dir, "add", "a")
    h.git(dir, "commit", "-q", "-m", "second")

    require("git.log_view").open({ max_count = 1000 })
    wait_buf_populated("^gitlog://")
    local log_buf = vim.api.nvim_get_current_buf()
    local log_win = vim.api.nvim_get_current_win()
    t.truthy(vim.api.nvim_buf_get_name(log_buf):match("^gitlog://"))
    local initial_lines = #vim.api.nvim_buf_get_lines(log_buf, 0, -1, false)
    t.truthy(initial_lines >= 2)

    -- Step into a commit, then <C-o> back to the log.
    vim.api.nvim_win_set_cursor(log_win, { 1, 0 })
    t.press("<CR>")
    t.truthy(vim.api.nvim_buf_get_name(0):match("^git://"))

    t.press("<C-o>")
    t.eq(vim.api.nvim_get_current_buf(), log_buf)
    t.eq(
        #vim.api.nvim_buf_get_lines(log_buf, 0, -1, false),
        initial_lines,
        "log buffer must repopulate on jump-back"
    )
end)

t.test("<CR> still dispatches after navigating away and back", function()
    local dir = make_repo({ a = "v1\n" })
    t.write(dir, "a", "v2\n")
    h.git(dir, "add", "a")
    h.git(dir, "commit", "-q", "-m", "second")

    -- Open the HEAD commit object buffer. Its cat-file output includes a
    -- "parent <sha>" line we can navigate from.
    local r = assert(require("git.repo").resolve(dir))
    require("git.object").open(r, "HEAD", { split = false })
    local first_obj_buf = vim.api.nvim_get_current_buf()
    local first_obj_win = vim.api.nvim_get_current_win()
    t.truthy(vim.api.nvim_buf_get_name(first_obj_buf):match("^git://"))

    -- Step into the parent commit. This hides first_obj_buf which has
    -- bufhidden=delete, so it gets unloaded.
    local parent_lnum = assert(find_line(first_obj_buf, "parent "))
    vim.api.nvim_win_set_cursor(first_obj_win, { parent_lnum, 0 })
    t.truthy(require("git.object").open_under_cursor())
    local parent_buf = vim.api.nvim_get_current_buf()
    t.truthy(parent_buf ~= first_obj_buf)

    -- <C-o> back to first_obj_buf. With bufhidden=delete, vim re-reads the
    -- URI, which previously raced with BufDelete-driven unbind and left
    -- state cleared, so open_under_cursor returned false.
    t.press("<C-o>")
    t.eq(vim.api.nvim_get_current_buf(), first_obj_buf)
    local tree_lnum = assert(find_line(first_obj_buf, "tree "))
    vim.api.nvim_win_set_cursor(first_obj_win, { tree_lnum, 0 })
    t.truthy(
        require("git.object").open_under_cursor(),
        "<CR> must work after returning to the buffer"
    )
end)

t.test(":G diff <CR> on + line falls back to worktree file", function()
    local dir = make_repo({ a = "v1\n" })
    t.write(dir, "a", "v2\n")
    assert(require("git.repo").resolve(dir))

    cmd.run({ "diff" })
    wait_buf_populated("%[Git diff%]")
    ---@type integer?
    local diff_buf
    for _, b in ipairs(vim.api.nvim_list_bufs()) do
        if vim.api.nvim_buf_get_name(b):match("%[Git diff%]") then
            diff_buf = b
        end
    end
    assert(diff_buf, "expected [Git diff] buffer")
    local win = vim.fn.bufwinid(diff_buf)
    vim.api.nvim_set_current_win(win)
    local lnum = assert(find_line(diff_buf, "+v2"))
    vim.api.nvim_win_set_cursor(win, { lnum, 0 })

    t.truthy(require("git.object").open_under_cursor())
    t.eq(vim.api.nvim_buf_get_name(0), vim.fs.joinpath(dir, "a"))
end)

---Run cmd.run via :lua so vim.fn.execute captures any nvim_echo output
---and suppresses it from headless stdout.
---@param args string[]
---@return string
local function run_capturing(args)
    return vim.trim(
        vim.fn.execute(
            string.format([[lua require("git.cmd").run(%s)]], vim.inspect(args))
        )
    )
end

---@return integer? pwin
local function find_preview_win()
    for _, w in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
        if vim.wo[w].previewwindow then
            return w
        end
    end
end

local function close_preview()
    pcall(vim.cmd.pclose)
end

t.test("quiet :G echoes single-line stdout", function()
    make_repo({ a = "x" })
    local out = run_capturing({ "config", "user.email" })
    t.truthy(
        out:match("t@t%.com"),
        "expected output to contain t@t.com, got: " .. out
    )
end)

t.test("quiet :G is silent on empty-output success", function()
    make_repo({ a = "x" })
    t.eq(run_capturing({ "config", "user.email", "new@t.com" }), "")
end)

t.test("quiet :G echoes 'git exited N' on silent failure", function()
    make_repo({ a = "x" })
    local out = run_capturing({ "config", "--get", "nonexistent.foo.bar" })
    t.truthy(
        out:match("git exited 1"),
        "expected output to contain 'git exited 1', got: " .. out
    )
end)

t.test("quiet :G echoes stderr on failure with output", function()
    make_repo({ a = "x" })
    local out = run_capturing({ "branch", "-d", "nonexistent-branch" })
    t.truthy(
        out:match("nonexistent%-branch"),
        "expected stderr mentioning the branch, got: " .. out
    )
end)

---@param fn fun(calls: { chunks: table, history: boolean, opts: table }[])
local function with_echo_stub(fn)
    ---@type { chunks: table, history: boolean, opts: table }[]
    local calls = {}
    local original = vim.api.nvim_echo
    vim.api.nvim_echo = function(chunks, history, opts)
        table.insert(calls, {
            chunks = chunks,
            history = history,
            opts = opts or {},
        })
        return original(chunks, history, opts)
    end
    local ok, err = pcall(fn, calls)
    vim.api.nvim_echo = original
    if not ok then
        error(err, 0)
    end
end

---@param calls { opts: table }[]
---@param status string
---@return boolean
local function has_status(calls, status)
    for _, c in ipairs(calls) do
        if c.opts.status == status then
            return true
        end
    end
    return false
end

t.test("streaming :G fetch (no bang) does not open a window", function()
    make_repo({ a = "x" })
    with_echo_stub(function(calls)
        local before = #vim.api.nvim_tabpage_list_wins(0)
        cmd.run({ "fetch" })
        t.wait_for(function()
            return has_status(calls, "failed")
                or has_status(calls, "success")
        end, "streaming job to terminate", 5000)
        t.eq(#vim.api.nvim_tabpage_list_wins(0), before, "no new window")
        t.falsy(find_preview_win(), "no preview window")
    end)
end)

t.test(
    "streaming :G fetch (no bang) emits failed progress on bad remote",
    function()
        make_repo({ a = "x" })
        with_echo_stub(function(calls)
            cmd.run({ "fetch", "nonexistent" })
            t.wait_for(function()
                return has_status(calls, "failed")
            end, "failed progress notification", 5000)
            ---@type { chunks: table, history: boolean, opts: table }?
            local final
            for _, c in ipairs(calls) do
                if c.opts.status == "failed" then
                    final = c
                    break
                end
            end
            t.truthy(final)
            ---@cast final -nil
            t.eq(final.opts.kind, "progress")
            t.falsy(final.history, "transient progress, not history")
            t.truthy(has_status(calls, "running"), "running progress emitted")
        end)
    end
)

t.test(
    "streaming :G fetch (no bang) on failure dumps output to :messages with ErrorMsg",
    function()
        make_repo({ a = "x" })
        with_echo_stub(function(calls)
            cmd.run({ "fetch", "nonexistent" })
            t.wait_for(function()
                return has_status(calls, "failed")
            end, "failed progress notification", 5000)
            local body = ""
            for _, c in ipairs(calls) do
                if
                    c.history == true
                    and c.chunks[1]
                    and c.chunks[1][2] == "ErrorMsg"
                then
                    body = c.chunks[1][1]
                    break
                end
            end
            t.truthy(body ~= "", "expected ErrorMsg history dump")
            local lower = string.lower(body)
            t.truthy(
                lower:match("repository")
                    or lower:match("remote")
                    or lower:match("fatal"),
                "expected error mention in dump, got: " .. body
            )
        end)
    end
)

t.test(
    "streaming :G fetch (no bang) on success does not dump to :messages",
    function()
        local remote = vim.fn.tempname()
        vim.fn.mkdir(remote, "p")
        h.git(remote, "init", "-q", "--bare")
        t.defer(function()
            vim.fn.delete(remote, "rf")
        end)

        local dir = make_repo({ a = "x" })
        h.git(dir, "remote", "add", "origin", remote)
        h.git(dir, "push", "-q", "origin", "main")

        with_echo_stub(function(calls)
            cmd.run({ "fetch", "origin" })
            t.wait_for(function()
                return has_status(calls, "success")
            end, "success progress notification", 5000)
            for _, c in ipairs(calls) do
                t.falsy(
                    c.history,
                    "success path must not echo to message history"
                )
            end
        end)
    end
)

t.test("streaming output buffer collects runs (failure path)", function()
    make_repo({ a = "x" })
    with_echo_stub(function(calls)
        cmd.run({ "fetch", "nonexistent" })
        t.wait_for(function()
            return has_status(calls, "failed")
        end, "failed progress notification", 5000)
    end)
    require("git.history").open()
    local buf = vim.api.nvim_get_current_buf()
    local lines = vim.api.nvim_buf_get_lines(buf, 0, -1, false)
    local found_header, found_fatal = false, false
    for _, l in ipairs(lines) do
        if l:match("^%$ git fetch nonexistent$") then
            found_header = true
        end
        if l:match("fatal:") then
            found_fatal = true
        end
    end
    t.truthy(found_header, "expected '$ git fetch nonexistent' header")
    t.truthy(found_fatal, "expected fatal: line in output buffer")
end)

t.test(
    "streaming :G! fetch (bang) opens preview window with terminal buffer",
    function()
        make_repo({ a = "x" })
        t.defer(close_preview)

        cmd.run({ "fetch" }, { bang = true })
        local pwin = find_preview_win()
        t.truthy(pwin, "expected preview window to exist")
        ---@cast pwin integer
        local buf = vim.api.nvim_win_get_buf(pwin)
        t.eq(vim.bo[buf].buftype, "terminal")
    end
)