local h = require("helpers")

require("git").init()

---Run the cursor-restore autocmd that was responsible for the original
---cursor-jump bug. Replicating it lets the regression test exercise the
---same interaction the user had in their config.
local function install_cursor_restore_autocmd()
    vim.api.nvim_create_autocmd("BufReadPost", {
        pattern = "*",
        command = 'silent! normal! g`"zv',
    })
end

---@param sidebar_buf integer
---@param needle string
---@return integer?
local function find_line(sidebar_buf, needle)
    for i, l in
        ipairs(vim.api.nvim_buf_get_lines(sidebar_buf, 0, -1, false))
    do
        if l:match(needle) then
            return i
        end
    end
end

---@return integer? sidebar_buf, integer? sidebar_win
local function find_sidebar()
    local buf, win
    for _, b in ipairs(vim.api.nvim_list_bufs()) do
        if vim.bo[b].filetype == "gitstatus" then
            buf = b
        end
    end
    for _, w in ipairs(vim.api.nvim_list_wins()) do
        if vim.api.nvim_win_get_buf(w) == buf then
            win = w
        end
    end
    return buf, win
end

---@param role string
---@return integer?
local function find_diff_win(role)
    for _, w in ipairs(vim.api.nvim_list_wins()) do
        if vim.w[w].git_diff_role == role then
            return w
        end
    end
end

---Set up a repo with one tracked-and-modified file, open the sidebar, and
---return the sidebar window plus the line of the file's entry.
---@param file_path string
---@param committed_content string
---@param worktree_content string
---@return integer sidebar_win
---@return integer entry_line
local function setup_sidebar_with_unstaged_file(
    file_path,
    committed_content,
    worktree_content
)
    local repo = h.make_repo({ [file_path] = committed_content })
    h.write(repo, file_path, worktree_content)
    vim.cmd("cd " .. repo)

    require("git.status_view").open({ placement = "sidebar" })
    local sidebar_buf, sidebar_win = find_sidebar()
    assert(sidebar_buf, "sidebar buffer should exist")
    assert(sidebar_win, "sidebar window should exist")

    local r = assert(
        require("git.repo").find(vim.fn.getcwd()),
        "repo should resolve for the test worktree"
    )
    r:refresh()
    vim.wait(1000, function()
        return r.status and #r.status:by_kind("unstaged") > 0
    end)

    local entry_line = assert(
        find_line(sidebar_buf, vim.pesc(file_path) .. "$"),
        file_path .. " should appear in sidebar"
    )
    return sidebar_win, entry_line
end

local function press(keys)
    local rhs = vim.api.nvim_replace_termcodes(keys, true, false, true)
    vim.api.nvim_feedkeys(rhs, "x", false)
end

---@param cond fun(): boolean
---@param msg string
local function wait_for(cond, msg)
    h.truthy(vim.wait(1000, cond), "timed out waiting for: " .. msg)
end

h.test(
    "stage with diff open: sidebar cursor stays put",
    function()
        install_cursor_restore_autocmd()
        local sidebar_win, line = setup_sidebar_with_unstaged_file(
            "zsh/rc",
            "ZSH=true\n",
            "ZSH=true\nmodified\n"
        )

        vim.api.nvim_set_current_win(sidebar_win)
        vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })

        press("<Tab>")
        wait_for(function()
            return find_diff_win("left") ~= nil
        end, "diff windows to appear")

        local r = assert(require("git.repo").find(vim.fn.getcwd()))
        vim.api.nvim_set_current_win(sidebar_win)
        press("s")
        wait_for(function()
            return #r.status:by_kind("staged") > 0
        end, "stage to propagate to repo state")

        h.eq(
            vim.api.nvim_win_get_cursor(sidebar_win),
            { line, 0 },
            "sidebar cursor should remain at the entry's original line"
        )
    end
)

h.test(
    "stage with diff open: diff foldmethod is preserved on refresh",
    function()
        local sidebar_win, line = setup_sidebar_with_unstaged_file(
            "zsh/rc",
            "# vim: set ft=zsh nowrap:\nZSH=true\n",
            "# vim: set ft=zsh nowrap:\nZSH=true\nmodified\n"
        )

        vim.api.nvim_set_current_win(sidebar_win)
        vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })

        press("<Tab>")
        wait_for(function()
            return find_diff_win("left") ~= nil
        end, "diff windows to appear")
        local left_win = assert(find_diff_win("left"))
        h.eq(
            vim.wo[left_win].foldmethod,
            "diff",
            "left diff foldmethod should be 'diff' after Tab"
        )

        local r = assert(require("git.repo").find(vim.fn.getcwd()))
        vim.api.nvim_set_current_win(sidebar_win)
        press("s")
        wait_for(function()
            return #r.status:by_kind("staged") > 0
        end, "stage to propagate to repo state")

        h.eq(
            vim.wo[left_win].foldmethod,
            "diff",
            "left diff foldmethod should still be 'diff' after stage refresh"
        )
    end
)

h.test("refresh on stage updates the index URI buffer's content", function()
    local sidebar_win, line = setup_sidebar_with_unstaged_file(
        "foo.txt",
        "v1\n",
        "v2\n"
    )

    vim.api.nvim_set_current_win(sidebar_win)
    vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })
    press("<Tab>")
    wait_for(function()
        return find_diff_win("left") ~= nil
    end, "diff windows to appear")

    local left_win = assert(find_diff_win("left"))
    local index_buf = vim.api.nvim_win_get_buf(left_win)
    h.eq(
        vim.api.nvim_buf_get_lines(index_buf, 0, -1, false),
        { "v1" },
        "index pane should initially show committed content"
    )

    vim.api.nvim_set_current_win(sidebar_win)
    press("s")
    wait_for(function()
        local first =
            vim.api.nvim_buf_get_lines(index_buf, 0, -1, false)[1]
        return first == "v2"
    end, "index pane to refresh to staged content")

    h.eq(
        vim.api.nvim_buf_get_lines(index_buf, 0, -1, false),
        { "v2" },
        "index pane should reflect staged content after refresh"
    )
end)

h.report()