local runner = require("jj.core.runner")

--- @class jj.utils
local M = {
	executable_cache = {},
	dependency_cache = {},
}

-- No-op setup, but keep it for API consistency in case we need it later.
function M.setup(_) end

--- Cache for executable checks to avoid repeated system calls

--- Check if an executable exists in PATH
--- @param name string The name of the executable to check
--- @return boolean True if executable exists, false otherwise
function M.has_executable(name)
	if M.executable_cache[name] ~= nil then
		return M.executable_cache[name]
	end

	local exists = vim.fn.executable(name) == 1
	M.executable_cache[name] = exists
	return exists
end

--- Check if the dependency is currently installed
--- @param module string The dependency module
--- @return boolean
function M.has_dependency(module)
	if M.dependency_cache[module] ~= nil then
		return true
	end

	local exists, _ = pcall(require, module)
	if not exists then
		M.notify(string.format("Module %s not installed", module), vim.log.levels.ERROR)
		return false
	end

	return true
end

--- Clear the executable cache (useful for testing or if PATH changes)
function M.clear_executable_cache()
	M.executable_cache = {}
end

--- Check if jj executable exists, show error if not
--- @return boolean True if jj exists, false otherwise
function M.ensure_jj()
	if not M.has_executable("jj") then
		M.notify("jj command not found", vim.log.levels.ERROR)
		return false
	end
	return true
end

--- Check if we're in a jj repository
--- @return boolean True if in jj repo, false otherwise
function M.is_jj_repo()
	if not M.ensure_jj() then
		return false
	end

	-- We require the runner here to avoid a circular dependency loop at startup
	local _, success = runner.execute({ "jj", "status" })
	return success
end

--- Get jj repository root path
--- @return string|nil The repository root path, or nil if not in a repo
function M.get_jj_root()
	if not M.ensure_jj() then
		return nil
	end

	-- We require the runner here to avoid a circular dependency loop at startup
	local output, success = runner.execute({ "jj", "root" })
	if success and output then
		return vim.trim(output)
	end
	return nil
end

--- Get a list of files modified in the current jj repository.
--- @return string[] A list of modified file paths
function M.get_modified_files()
	if not M.ensure_jj() then
		return {}
	end

	-- We require the runner here to avoid a circular dependency loop at startup
	local result, success = runner.execute({ "jj", "diff", "--name-only" }, "Error getting diff")
	if not success or not result then
		return {}
	end

	local files = {}
	-- Split the result into lines and add each file to the table
	for file in result:gmatch("[^\r\n]+") do
		table.insert(files, file)
	end

	return files
end

---- Notify function to display messages with a title
--- @param message string The message to display
--- @param level? number The log level (default: INFO)
--- @param timeout number? The timeout duration in milliseconds (default: 3000)
function M.notify(message, level, timeout)
	level = level or vim.log.levels.INFO
	timeout = timeout or 3000
	vim.notify(message, level, { title = "JJ", timeout = timeout })
end

--- URL encode a string for use in URLs
--- @param str string The string to encode
--- @return string The URL-encoded string
function M.url_encode(str)
	return (str:gsub("([^%w%-_.~])", function(c)
		return string.format("%%%02X", string.byte(c))
	end))
end

--- URL-encode a file path for use in URLs.
--- Encodes each path segment and preserves `/` separators.
--- Also normalizes Windows path separators (`\` -> `/`).
--- @param path string
--- @return string
function M.url_encode_path(path)
	path = (path or ""):gsub("\\", "/")
	local parts = vim.split(path, "/", { plain = true })
	for i, seg in ipairs(parts) do
		parts[i] = M.url_encode(seg)
	end
	return table.concat(parts, "/")
end

--- Check whether a path points to an existing file.
--- @param path string|nil
--- @return boolean
function M.is_file(path)
	if not path or path == "" then
		return false
	end
	local st = vim.uv.fs_stat(path)
	return st ~= nil and st.type == "file"
end

--- Parse a jj:// virtual buffer URI.
--- Returns nil, nil if the name is not a jj:// URI or has an invalid format.
--- @param name string
--- @return string|nil change_id
--- @return string|nil path
function M.parse_jj_uri(name)
	if not vim.startswith(name, "jj://") then
		return nil, nil
	end
	return name:match("^jj://([^/]+)/(.+)$")
end

--- Normalize a user-provided file path to a cwd-relative path for jj commands.
---
--- Rules:
--- - `%` resolves to the current buffer absolute file path.
--- - Absolute paths are converted to cwd-relative paths.
--- - Relative paths are kept relative (already cwd-relative).
---
--- @param path string|nil Path provided by the user (`%`, absolute, or relative)
--- @return string|nil normalized_path Cwd-relative normalized path
--- @return string|nil err Error message when normalization fails
function M.normalize_relative_path(path)
	path = vim.trim(path or "")
	if path == "" then
		return nil, "Path is empty"
	end

	if path == "%" then
		path = vim.api.nvim_buf_get_name(0)
		if path == "" then
			return nil, "Current buffer has no file path"
		end
		local _, jj_path = M.parse_jj_uri(path)
		if jj_path then
			return jj_path, nil
		end
	end

	path = vim.fs.normalize(path)

	local is_absolute = vim.startswith(path, "/") or path:match("^%a:/") ~= nil
	if is_absolute then
		local cwd = vim.uv.cwd()
		if not cwd or cwd == "" then
			return nil, "Could not determine current working directory"
		end
		cwd = vim.fs.normalize(cwd)
		local rel = M.relpath(cwd, path)
		if not rel then
			return nil, "Path is outside current working directory"
		end
		path = rel
	end

	path = path:gsub("^%./", "")
	if path == "" then
		return nil, "Path is empty after normalization"
	end

	return path, nil
end

--- Compute a repository-relative path.
--- Returns nil if `path` is outside of `root`.
--- @param root string
--- @param path string
--- @return string|nil
function M.relpath(root, path)
	if not root or root == "" or not path or path == "" then
		return nil
	end

	local ok_norm_root, norm_root = pcall(vim.fs.normalize, root)
	local ok_norm_path, norm_path = pcall(vim.fs.normalize, path)
	if not ok_norm_root or not ok_norm_path then
		norm_root, norm_path = root, path
	end

	local ok_rel, rel = pcall(vim.fs.relpath, norm_root, norm_path)
	if ok_rel and rel and rel ~= "" and not rel:match("^%.%.") then
		return rel
	end

	local prefix = norm_root
	if not prefix:match("/$") then
		prefix = prefix .. "/"
	end
	if vim.startswith(norm_path, prefix) then
		return norm_path:sub(#prefix + 1)
	end

	return nil
end

--- Normalize a git remote URL to an HTTPS repo URL.
--- Supports:
--- - `git@host:owner/repo(.git)`
--- - `ssh://git@host/owner/repo(.git)`
--- - `https://host/owner/repo(.git)`
--- @param raw_url string
--- @return string|nil repo_url HTTPS base repo URL (no trailing .git)
--- @return string|nil host Hostname extracted from the remote
function M.normalize_remote_url(raw_url)
	if not raw_url or raw_url == "" then
		return nil, nil
	end

	raw_url = raw_url:gsub("%.git$", "")

	-- scp-like SSH: git@host:owner/repo
	if raw_url:match("^git@") then
		local host = raw_url:match("^git@([^:]+):")
		local repo_path = raw_url:match("^git@[^:]+:(.+)$")
		if host and repo_path then
			return "https://" .. host .. "/" .. repo_path, host
		end
	end

	-- ssh://git@host/owner/repo
	if raw_url:match("^ssh://") then
		local host = raw_url:match("^ssh://[^@]+@([^/]+)/") or raw_url:match("^ssh://([^/]+)/")
		local rest = raw_url:gsub("^ssh://[^@]+@", ""):gsub("^ssh://", "")
		local repo_path = rest:match("^[^/]+/(.+)$")
		if host and repo_path then
			repo_path = repo_path:gsub("%.git$", "")
			return "https://" .. host .. "/" .. repo_path, host
		end
	end

	-- HTTPS
	local host = raw_url:match("^https?://([^/]+)")
	if host then
		return raw_url, host
	end

	return nil, nil
end

--- Open a URL using the system default handler.
--- Prefers `vim.ui.open()` when available.
--- @param url string
function M.open_url(url)
	if not url or url == "" then
		return
	end

	local is_windows = vim.fn.has("win32") == 1 or vim.fn.has("win64") == 1
	if is_windows then
		-- Avoid `cmd /c start` parsing issues with `&` and other special chars in URLs.
		local job_id = vim.fn.jobstart({ "rundll32.exe", "url.dll,FileProtocolHandler", url }, { detach = true })
		if job_id <= 0 then
			-- Fallback for environments where rundll32 is unavailable.
			vim.fn.jobstart({ "cmd.exe", "/c", "start", "", url }, { detach = true })
		end
		return
	end

	if vim.ui and type(vim.ui.open) == "function" then
		vim.ui.open(url)
		return
	end

	local open_cmd = vim.fn.has("mac") == 1 and "open" or "xdg-open"
	vim.fn.jobstart({ open_cmd, url }, { detach = true })
end

--- Best-effort unquoting of a jj `RefSymbol` rendering.
---
--- `RefSymbol` values are displayed as revset symbols, which may be quoted and
--- escaped if necessary. For browser URLs, we generally want the raw name.
---
--- This handles the common cases of surrounding single/double quotes.
--- @param s string|nil
--- @return string
function M.unquote_refsymbol(s)
	s = vim.trim(s or "")
	if s == "" then
		return ""
	end
	local first = s:sub(1, 1)
	local last = s:sub(-1)
	if (first == '"' and last == '"') or (first == "'" and last == "'") then
		s = s:sub(2, -2)
		-- Minimal unescaping (covers typical `\"` and `\\` sequences)
		s = s:gsub("\\\\", "\\"):gsub('\\"', '"'):gsub("\\'", "'")
	end
	return s
end

--- Get all bookmarks in the repository, filters out deleted bookmarks
--- @return string[] List of bookmarks, or empty list if none found
function M.get_all_bookmarks()
	-- Use a custom template to output just the bookmark names, one per line
	-- This is more reliable than parsing the default output format
	local cmd = {
		"jj",
		"bookmark",
		"list",
		"-T",
		'if(!self.remote(), name ++ if(!self.present(), " (deleted)", "") ++ "\n")',
	}
	local bookmarks_output, success = runner.execute(cmd, "Failed to get bookmarks", nil, true)
	if not success or not bookmarks_output then
		return {}
	end

	-- Parse bookmarks from template output
	local bookmarks = {}
	local seen = {}
	for line in bookmarks_output:gmatch("[^\n]+") do
		local bookmark = vim.trim(line)
		if bookmark ~= "" and not seen[bookmark] then
			-- Skip bookmarks containing "Hint:" or "(deleted)"
			if not bookmark:match("Hint:") and not bookmark:match("%(deleted%)") then
				table.insert(bookmarks, bookmark)
				seen[bookmark] = true
			end
		end
	end

	return bookmarks
end

--- Get all bookmarks in the repository, including deleted ones
--- @return {name: string, is_deleted: boolean}[] bookmarks List of bookmarks
function M.get_all_bookmarks_with_status()
	local cmd = {
		"jj",
		"bookmark",
		"list",
		"-T",
		'if(!self.remote(), name ++ if(!self.present(), " (deleted)", "") ++ "\n")',
		"--quiet",
	}
	local bookmarks_output, success = runner.execute(cmd, "Failed to get bookmarks", nil, true)

	if not success or not bookmarks_output then
		return {}
	end

	local bookmarks = {}
	local seen = {}
	for line in bookmarks_output:gmatch("[^\n]+") do
		local trimmed = vim.trim(line)
		if trimmed ~= "" then
			local is_deleted = trimmed:match(" %(deleted%)$") ~= nil
			local name = trimmed:gsub(" %(deleted%)$", "")
			if not seen[name] then
				table.insert(bookmarks, { name = name, is_deleted = is_deleted })
				seen[name] = true
			end
		end
	end

	return bookmarks
end

--- Get unique base bookmark names from a string of space-separated bookmarks.
--- Handles the output of the template `bookmarks.map(|b| b.name() ++ "::" ++ b.present()).join(" ")`
--- Strips asterisks, strips @remote, and deduplicates.
--- @param bookmark_str string
--- @return {name: string, is_deleted: boolean}[] List of unique bookmark objects
function M.parse_bookmark_names(bookmark_str)
	local raw_items = vim.split(bookmark_str, "%s+", { trimempty = true })
	local unique_bookmarks = {}
	local seen = {}

	for _, item in ipairs(raw_items) do
		local parts = vim.split(item, "::", { plain = true })
		if #parts == 2 then
			-- Strip asterisks and @remote and ??
			local base_name = parts[1]:gsub("%*", ""):gsub("@.*$", ""):gsub("%?%?", "")
			local is_deleted = parts[2] == "false"

			if base_name ~= "" and not seen[base_name] then
				table.insert(unique_bookmarks, { name = base_name, is_deleted = is_deleted })
				seen[base_name] = true
			end
		end
	end

	return unique_bookmarks
end

--- Get unique base bookmark names and statuses for a given revset
--- @param revset string
--- @return {name: string, is_deleted: boolean}[]|nil ret List of bookmark objects, or nil on failure
function M.get_bookmarks_for_rev(revset)
	-- Retrieve name and deleted status
	local cmd = {
		"jj",
		"log",
		"-r",
		revset,
		"-T",
		'bookmarks.map(|b| b.name() ++ "::" ++ b.present()).join(" ")',
		"--no-graph",
	}

	local output, success = runner.execute(cmd, string.format("Error retrieving bookmark for `%s`", revset), nil, false)

	if not success or not output then
		return nil
	end

	return M.parse_bookmark_names(output)
end

--- Get all tags in a repository
--- @return string[] List of bookmarks, or empty list if none found
function M.get_all_tags()
	-- Use a custom template to output just the bookmark names, one per line
	-- This is more reliable than parsing the default output format
	local cmd = {
		"jj",
		"tag",
		"list",
		"--quiet",
		"--sort",
		"committer-date-",
		"-T",
		'if(!self.remote(), name ++ if(!self.present(), " (deleted)", "") ++ "\n")',
	}
	local bookmarks_output, success = runner.execute(cmd, "Failed to get bookmarks", nil, true)
	if not success or not bookmarks_output then
		return {}
	end

	-- Parse tags from template output
	local tags = {}
	local seen = {}
	for line in bookmarks_output:gmatch("[^\n]+") do
		local tag = vim.trim(line)
		if tag ~= "" and not seen[tag] then
			-- Skip tags containing  "(deleted)"
			if not tag:match("%(deleted%)") then
				table.insert(tags, tag)
				seen[tag] = true
			end
		end
	end

	return tags
end

--- Whether or not the repository is colocated
--- @return boolean
function M.is_colocated()
	local output, success = runner.execute(
		{ "jj", "git", "colocation", "status" },
		"Failed to determine if repository is colocated",
		nil,
		true
	)

	if not success or not output then
		return false
	end

	return vim.startswith(vim.trim(output), "Workspace is currently colocated with Git.")
end

--- Get all bookmarks in the repository, filters out deleted bookmarks
--- @return string[] List of bookmarks, or empty list if none found
function M.get_untracked_bookmarks()
	-- Use a custom template to output just the bookmark names, one per line
	-- This is more reliable than parsing the default output format
	local cmd = {
		"jj",
		"bookmark",
		"list",
		"-a",
		"-T",
		'if(self.remote() && !self.tracked(), name ++ if(!self.present(), " (deleted)", "") ++ "\n")',
	}

	local bookmarks_output, success = runner.execute(cmd, "Failed to get untracked bookmarks", nil, true)
	if not success or not bookmarks_output then
		return {}
	end

	-- Parse bookmarks from template output
	local bookmarks = {}
	local seen = {}
	for line in bookmarks_output:gmatch("[^\n]+") do
		local bookmark = vim.trim(line)
		if bookmark ~= "" and not seen[bookmark] then
			-- Skip bookmarks containing "Hint:" or "(deleted)"
			if not bookmark:match("Hint:") and not bookmark:match("%(deleted%)") then
				table.insert(bookmarks, bookmark)
				seen[bookmark] = true
			end
		end
	end

	return bookmarks
end

--- Get git remotes for the current jj repository
--- @return {name: string, url: string}[]|nil A list of remotes with name and URL
function M.get_remotes()
	local remote_list, remote_success =
		runner.execute({ "jj", "git", "remote", "list" }, "Failed to get git remote", nil, true)

	if not remote_success or not remote_list then
		return
	end

	-- Parse remotes into a table
	local remotes = {}
	for line in remote_list:gmatch("[^\n]+") do
		local name, url = line:match("^(%S+)%s+(.+)$")
		if name and url then
			table.insert(remotes, { name = name, url = url })
		end
	end

	return remotes
end

--- Open a PR/MR on the remote for a given bookmark
--- @param bookmark string The bookmark to create a PR for
function M.open_pr_for_bookmark(bookmark)
	-- Get all git remotes
	local remotes = M.get_remotes()

	if not remotes or #remotes == 0 then
		M.notify("No git remotes found", vim.log.levels.ERROR)
		return
	end

	-- Helper function to open PR for a given remote URL
	local function open_pr_with_url(raw_url)
		local repo_url, host = M.normalize_remote_url(raw_url)
		if not repo_url or not host then
			M.notify("Unsupported remote URL: " .. (raw_url or ""), vim.log.levels.ERROR)
			return
		end

		-- Construct the appropriate PR/MR URL based on the platform
		local encoded_bookmark = M.url_encode(bookmark)
		local pr_url

		if host:match("gitlab") then
			-- GitLab merge request URL
			pr_url = repo_url .. "/-/merge_requests/new?merge_request[source_branch]=" .. encoded_bookmark
		elseif host:match("gitea") or host:match("forgejo") then
			-- Gitea/Forgejo compare URL
			pr_url = repo_url .. "/compare/" .. encoded_bookmark
		else
			-- Default to GitHub-style compare URL (works for GitHub, Gitea, etc.)
			pr_url = repo_url .. "/compare/" .. encoded_bookmark .. "?expand=1"
		end

		M.open_url(pr_url)
		M.notify(string.format("Opening PR for bookmark `%s`", bookmark), vim.log.levels.INFO)
	end

	-- If only one remote, use it directly
	if #remotes == 1 then
		open_pr_with_url(remotes[1].url)
		return
	end

	-- Multiple remotes: prompt user to select
	vim.ui.select(remotes, {
		prompt = "Select remote to open PR on: ",
		format_item = function(item)
			return item.name .. " (" .. item.url .. ")"
		end,
	}, function(choice)
		if choice then
			open_pr_with_url(choice.url)
		end
	end)
end

--- Check if a given revset represents an immutable change
--- @param revset string The revset to check
--- @return boolean True if the change is immutable, false otherwise
function M.is_change_immutable(revset)
	local cmd = {
		"jj",
		"log",
		"--no-graph",
		"-r",
		revset,
		"-T",
		"immutable",
		"--quiet",
	}

	local output, success = runner.execute(cmd, "Error checking change immutability", nil, true)
	if not success or not output then
		return false
	end

	return vim.trim(output) == "true"
end

--- Check if a given revset is empty
--- @param revset string The revset to check
--- @return boolean True if the revset is empty, false otherwise
function M.is_change_empty(revset)
	local cmd = {
		"jj",
		"log",
		"--no-graph",
		"-r",
		revset,
		"-T",
		"empty",
		"--quiet",
	}

	local output, success = runner.execute(cmd, "Error checking if revset is empty", nil, true)
	if not success or not output then
		return false
	end

	return vim.trim(output) == "true"
end

--- Check if a given revset has conflicts
--- @param revset string The revset to check
--- @return boolean True if the revset has conflicts, false otherwise
function M.is_change_conflicted(revset)
	local cmd = {
		"jj",
		"log",
		"--no-graph",
		"-r",
		revset,
		"-T",
		"conflict",
		"--quiet",
	}

	local output, success = runner.execute(cmd, "Error checking if revset has conflicts", nil, true)

	if not success or not output then
		return false
	end

	return vim.trim(output) == "true"
end

--- Build describe text for a given revision
--- @param revset? string The revision to describe (default: @)
--- @return string[]|nil
function M.get_describe_text(revset)
	if not revset or revset == "" then
		revset = "@"
	end

	local old_desc_cmd = {
		"jj",
		"log",
		"-r",
		revset,
		"--quiet",
		"--no-graph",
		"-T",
		'coalesce(description, "\\n")',
	}
	local old_description_raw, success = runner.execute(old_desc_cmd, "Failed to get old description")
	if not old_description_raw or not success then
		return nil
	end

	local cmd_files = {
		"jj",
		"log",
		"-r",
		revset,
		"--quiet",
		"--no-graph",
		"-T",
		"self.diff().summary()",
	}

	local status_result, success2 = runner.execute(cmd_files, "Error getting status")
	if not success2 then
		return nil
	end

	local parser = require("jj.core.parser")
	local status_files = parser.get_status_files(status_result)
	local old_description = vim.trim(old_description_raw)
	local description_lines = vim.split(old_description, "\n")
	local text = {}
	for _, line in ipairs(description_lines) do
		table.insert(text, line)
	end
	table.insert(text, "")
	table.insert(text, "JJ: Change ID: " .. revset)
	table.insert(text, "JJ: This commit contains the following changes:")
	for _, item in ipairs(status_files) do
		table.insert(text, string.format("JJ:     %s %s", item.status, item.file))
	end
	table.insert(text, "JJ:")
	table.insert(text, 'JJ: Lines starting with "JJ:" (like this one) will be removed')

	return text
end

---
--- Get the commit id from a given revision. Returns nil and notifies an error if multiple commit_ids are found for a single revset
--- @param revset string The revset to extract the commit id from
--- @return string|nil
function M.get_commit_id(revset)
	local cmd = {
		"jj",
		"log",
		"--no-graph",
		"-r",
		revset,
		"-T",
		'commit_id ++ "\\n"',
		"--quiet",
	}
	local output, success = runner.execute(cmd, "Error extracting commit id", nil, true)
	if not success or not output then
		return nil
	end

	local id = vim.split(output, "\n", { trimempty = true })
	if #id > 1 then
		M.notify(
			string.format(
				"A unique `commit_id` for revision `%s` was expected, but it has multiple ones.\nThis is not currently supported.",
				revset
			),
			vim.log.levels.ERROR,
			5000
		)
		return
	end

	return vim.trim(output)
end

---
--- Get the commit id of the current revision
--- @return string|nil
function M.get_current_commit_id()
	local cmd = {
		"jj",
		"log",
		"--no-graph",
		"-r",
		"@",
		"-T",
		'commit_id ++ "\\n"',
		"--quiet",
	}
	local output, success = runner.execute(cmd, "Error extracting current revision's commit id", nil, true)
	if not success or not output then
		return nil
	end

	return vim.trim(output)
end

--- Return a commit id that is expected to exist on a given remote.
---
--- This is a best-effort heuristic used for browser URLs: if a commit isn't
--- reachable from the remote's bookmarks, most web UIs will 404.
---
--- Strategy:
--- - Starting from `start_revset`, walk back first-parent (`revset-`) up to
---   `max_walkback` times until the commit is contained in
---   `::remote_bookmarks(remote="<remote_name>")`.
--- - If still not found, return the commit id of `trunk()`.
---
--- @param start_revset string Starting point revset (e.g. "@")
--- @param remote_name string Remote name (e.g. "origin")
--- @param max_walkback? integer Maximum number of parents to traverse (default: 20)
--- @return string|nil commit_id
function M.get_pushed_commit_id(start_revset, remote_name, max_walkback)
	max_walkback = max_walkback or 20
	start_revset = (start_revset and start_revset ~= "") and start_revset or "@"
	remote_name = (remote_name and remote_name ~= "") and remote_name or "origin"

	-- Build a revset expression string we can embed in a template StringLiteral.
	local remote_literal = remote_name:gsub("\\", "\\\\"):gsub('"', '\\"')
	local templ = [[if(self.contained_in("::remote_bookmarks(remote='%s')"), commit_id)]]
	templ = string.format(templ, remote_literal)

	-- If `start_revset` is already a commit id (or change id), we still let jj
	-- resolve it; otherwise, treat it as a revset expression.
	local current = start_revset
	for _ = 0, max_walkback do
		-- Use a single-quoted StringLiteral for the revset, so we can keep the
		-- remote name quoted inside the revset expression.
		local cmd = {
			"jj",
			"log",
			"-r",
			current,
			"--no-graph",
			"--quiet",
			"-T",
			templ,
		}

		local out, ok = runner.execute(cmd, "Error determining remote-reachable commit", nil, true)
		if ok and out and not out:match("^%s*$") then
			return vim.trim(out)
		end
		current = current .. "-"
	end

	return M.get_commit_id("trunk()")
end

--- Return a remote bookmark name pointing at `revset` on `remote_name`.
---
--- If there are 0 or multiple matching bookmarks and none of those are neither `main` nor `master`, returns nil.
--- This avoids choosing an arbitrary name when multiple bookmarks point to the
--- same commit.
---
--- @param revset string
--- @param remote_name string
--- @return string|nil bookmark_name
function M.get_unique_remote_bookmark_name(revset, remote_name)
	revset = (revset and revset ~= "") and revset or "@"
	remote_name = (remote_name and remote_name ~= "") and remote_name or "origin"

	-- Render remote bookmarks as tab-separated pairs: <remote>\t<name>\n
	local tmpl = [[self.remote_bookmarks().map(|b| b.remote() ++ "\t" ++ b.name() ++ "\n").join("")]]
	local cmd = {
		"jj",
		"log",
		"-r",
		revset,
		"--no-graph",
		"--quiet",
		"-T",
		tmpl,
	}

	local out, ok = runner.execute(cmd, "Error getting remote bookmarks", nil, true)
	if not ok or not out or out:match("^%s*$") then
		return nil
	end

	local matches = {}
	for line in out:gmatch("[^\r\n]+") do
		local remote_sym, name_sym = line:match("^(.-)\t(.*)$")
		local r = M.unquote_refsymbol(remote_sym)
		local n = M.unquote_refsymbol(name_sym)
		if r == remote_name and n ~= "" then
			table.insert(matches, n)
		end
	end

	if #matches == 1 then
		return matches[1]
	elseif #matches > 1 then
		for _, name in ipairs(matches) do
			-- Unless it's main or master which takes precedence
			if name == "main" or name == "master" then
				return name
			end
		end
	end
	return nil
end

--- Extract the description from the describe text
--- @param lines string[] The lines of a described change
--- @return string|nil
function M.extract_description_from_describe(lines)
	local final_lines = {}
	for _, line in ipairs(lines) do
		if not line:match("^JJ:") then
			table.insert(final_lines, line)
		end
	end
	-- Join lines and trim leading/trailing whitespace
	local trimmed_description = table.concat(final_lines, "\n"):gsub("^%s+", ""):gsub("%s+$", "")
	if trimmed_description == "" then
		-- If nothing return nil
		return
	end
	return trimmed_description
end

--- Reload loaded file buffers after working-copy changes.
function M.reload_changed_file_buffers()
	vim.cmd.checktime()
end

--- Using the gh cli lists all open prs
--- @param opts {limit: integer|nil}
--- @return {number: integer, title: string, author: string}[]|nil
function M.list_github_prs(opts)
	if not M.has_executable("gh") then
		M.notify("Missing `gh` executable to list prs", vim.log.levels.ERROR)
		return
	end

	-- Set the default limit
	local limit = 100

	if opts and opts.limit then
		limit = opts.limit
	end

	-- Start with a hardcoded limit of 100
	local cmd = {
		"gh",
		"pr",
		"list",
		"-L",
		tostring(limit),
		"--json",
		"number,title,author",
		"--jq",
		[[.[] | "#\(.number);;;\(.title);;;(@\(.author.login))"]],
	}

	-- Run the command to get the pr's
	local output, success = runner.execute(cmd, "Failed to get prs")
	if not success or not output then
		return
	end

	local open_prs = {}
	-- Split each line
	local lines = vim.split(output, "\n", { trimempty = true })
	for _, line in ipairs(lines) do
		local parts = vim.split(line, ";;;", { trimempty = true })
		if #parts == 3 then
			local number = tonumber(parts[1]:match("#(%d+)"))
			local title = parts[2]
			local author = parts[3]
			if number and title and author then
				table.insert(open_prs, { number = number, title = title, author = author })
			end
		else
			M.notify("Unexpected PR list format: " .. line, vim.log.levels.WARN)
		end
	end

	return open_prs
end

-- Open first conflicted file, runs edit on the conflicted revision and opens the first conflicted file in a buffer.
--- @param revset string The revset to check for conflicts
function M.open_first_conflicted_file(revset)
	if not revset or revset == "" then
		M.notify("No revset provided to open conflicted file", vim.log.levels.ERROR)
		return
	elseif not M.is_change_conflicted(revset) then
		return
	end

	local repo_root = M.get_jj_root()
	local cmd = {
		"jj",
		"resolve",
		"-r",
		revset,
		"--list",
	}

	-- Resolve the first conflicted path before editing so we can still open it
	-- reliably when the current working directory is outside the repo root.
	local list_output, list_ok =
		runner.execute(cmd, string.format("could not list conflicted files for '%s'", revset), nil, true)

	local first_conflicted_path
	if list_ok and type(list_output) == "string" and list_output ~= "" then
		for _, line in ipairs(vim.split(list_output, "\n", { trimempty = true })) do
			local rel_path = vim.trim(line:gsub("^[-*]%s+", ""))
			if rel_path ~= "" then
				first_conflicted_path = rel_path
				break
			end
		end
	end

	local _, ok = runner.execute(
		{ "jj", "edit", revset, "--ignore-immutable" },
		string.format("could not edit revision '%s'", revset)
	)

	if not ok then
		return
	end

	M.reload_changed_file_buffers()
	M.notify(string.format("Editing conflicted revision `%s`", revset), vim.log.levels.INFO)

	if first_conflicted_path then
		local first_conflicted_file = repo_root and vim.fs.joinpath(repo_root, first_conflicted_path)
			or first_conflicted_path
		local escaped = vim.fn.fnameescape(first_conflicted_file)
		local existing_buf = vim.fn.bufnr(first_conflicted_file)

		if existing_buf ~= -1 and vim.api.nvim_buf_is_loaded(existing_buf) then
			local modified = vim.bo[existing_buf].modified
			if not modified then
				vim.cmd("bdelete! " .. existing_buf)
			end
		end

		vim.cmd("edit! " .. escaped)
		vim.cmd("checktime " .. escaped)
	end
end

--- Extract selected lines from visual mode, and the marks for the start and end lines.
--- @param bufnr integer The buffer number to get the selection from
--- @return string[]|nil The selected lines, or nil if not in visual mode
--- @return integer|nil The start line of the selection (1-based)
--- @return integer|nil The end line of the selection (1-based)
function M.get_visual_selection(bufnr)
	local mode = vim.fn.mode()
	if mode ~= "v" and mode ~= "V" and mode ~= "\22" then
		return nil, nil, nil
	end

	local selected_start_line = vim.fn.line("v")
	local selected_end_line = vim.fn.line(".")
	if selected_start_line > selected_end_line then
		selected_start_line, selected_end_line = selected_end_line, selected_start_line
	end

	local lines = vim.api.nvim_buf_get_lines(bufnr, selected_start_line - 1, selected_end_line, false)

	return lines, selected_start_line, selected_end_line
end

return M