## vim:ft=zsh:foldmethod=marker
##
## vcs_info - provide version control information
##
## Written by Frank Terbeck <ft@bewatermyfriend.org>
##
## This file and all corresponding files in Functions/VCS_Info/ are
## distributed under the same BSD-ish license as zsh itself.
##

setopt localoptions noksharrays extendedglob NO_shwordsplit
local file func sys
local -a static_functions msgs
local -i maxexports

static_functions=(
    VCS_INFO_adjust
    VCS_INFO_bydir_detect
    VCS_INFO_check_com
    VCS_INFO_formats
    VCS_INFO_get_cmd
    VCS_INFO_hexdump
    VCS_INFO_hook
    VCS_INFO_set-patch-format
    VCS_INFO_set-branch-format
    VCS_INFO_maxexports
    VCS_INFO_nvcsformats
    VCS_INFO_patch2subject
    VCS_INFO_quilt
    VCS_INFO_reposub
    VCS_INFO_set

    vcs_info_hookadd
    vcs_info_hookdel
    vcs_info_lastmsg
    vcs_info_printsys
    vcs_info_setsys
)

for func in ${static_functions} ; do
    autoload -Uz ${func}
done

[[ -n ${(Mk)parameters:#vcs_info_msg_<->_} ]] && unset ${parameters[(I)vcs_info_msg_<->_]}
VCS_INFO_maxexports
VCS_INFO_set --nvcs '-preinit-'
vcs_info_setsys

# and now, finally create the real vcs_info function
vcs_info () {
    emulate -L zsh
    setopt extendedglob NO_warn_create_global

    [[ -r . ]] || return 0

    local pat
    local -i retval
    local -a enabled disabled dps
    local usercontext vcs rrn quiltmode
    local -x LC_MESSAGES
    local -i maxexports
    local -a msgs

    # vcs_comm is used internally for passing values among VCS_INFO_* functions.
    # It is not part of the public API.
    #
    # VCS_INFO_detect_* functions should set vcs_comm[basedir] to the path to
    # the root of the working copy.
    #
    # hook_com, backend_misc, and user_data are public API; see zshcontrib(1)
    # and Misc/vcs_info-examples.
    local -A vcs_comm hook_com backend_misc user_data

    LC_MESSAGES=C
    if [[ -n ${LC_ALL} ]]; then
        local -x LANG
        LANG=${LC_ALL}
        local -x LC_ALL
    fi
    vcs='-init-'; rrn='-all-'; quiltmode='addon'
    usercontext=${1:-default}

    VCS_INFO_hook "start-up"
    retval=$?
    if (( retval == 1 )); then
        return 0
    elif (( retval == 2 )); then
        # This needs `max-exports' set. We're still setting it again later
        # for more specific contexts.
        VCS_INFO_maxexports
        VCS_INFO_set --nvcs
        return 0
    fi

    zstyle -a ":vcs_info:${vcs}:${usercontext}:${rrn}" "enable" enabled
    (( ${#enabled} == 0 )) && enabled=( all )

    if [[ -n ${(M)enabled:#(#i)none} ]] ; then
        [[ -n ${vcs_info_msg_0_} ]] && VCS_INFO_set --nvcs
        return 0
    fi

    if [[ -n ${(M)enabled:#(#i)all} ]] ; then
        enabled=( ${VCS_INFO_backends} )
        zstyle -a ":vcs_info:${vcs}:${usercontext}:${rrn}" "disable" disabled
    fi

    zstyle -a ":vcs_info:${vcs}:${usercontext}:${rrn}" "disable-patterns" dps

    for pat in ${dps} ; do
        if [[ ${PWD} == ${~pat} ]] ; then
            VCS_INFO_maxexports
            [[ -n ${vcs_info_msg_0_} ]] && VCS_INFO_set --nvcs
            return 0
        fi
    done

    VCS_INFO_maxexports

    local -A chosen_vcs_comm chosen_backend_misc
    local chosen_vcs basedir_realpath chosen_basedir_realpath choose_first_available

    for vcs in ${enabled} ; do
        [[ -n ${(M)disabled:#${vcs}} ]] && continue
        if (( ${+functions[VCS_INFO_detect_${vcs}]} == 0 )) ; then
            printf 'vcs_info: configured unknown backend: '\''%s'\''\n' ${vcs}
            printf 'vcs_info: use '\''vcs_info_printsys'\'' to find supported systems.\n'
            continue
        fi
        vcs_comm=()
        VCS_INFO_get_cmd
        if VCS_INFO_detect_${vcs}; then
            # Most backends already set vcs_comm[basedir] to an absolute path
            # with symlinks resolved:
            #
            # * Backends using VCS_INFO_bydir_detect:
            #   bzr, cdv, darcs, fossil, hg, mtn, p4, svn
            #
            # * cvs - custom logic, but uses :P too
            #
            # * git - $(git rev-parse --show-toplevel) resolves symlinks and
            #   returns an absolute path
            #
            # * for tla (GNU Arch) I can't find any online documentation or
            #   packages (seems to be dead)
            #
            # * svk doesn't use :P modifier and returns the path as is from
            #   the config file (as far as I understand)
            #
            # So I'm not sure whether to modify the backends or just resolve
            # the path here to be sure. VCS_INFO_get_data_* usually reads
            # vcs_comm[basedir] too. In particular, I'm not sure if it's safe to
            # resolve symlinks in vcs_comm[basedir] for svk.
            #
            # Because most backends already do :P substitution, I expect all
            # the info needed to resolve the path to be cached in memory by the
            # OS (so it shouldn't cause performance issues).
            basedir_realpath="${vcs_comm[basedir]:P}"

            zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" choose-closest-backend
            choose_first_available=$?

            [[ "${PWD:P}/" == "${basedir_realpath}"/* ]] || [[ "${basedir_realpath}" == "/" ]] || choose_first_available=1

            # If choose_first_available is 0 at this point, all basedir_realpaths
            # (and thus chosen_basedir_realpath) are parents (and thus prefixes)
            # of PWD:P. So comparing their lengths is enough to figure out which
            # one is closer to PWD.
            if (( choose_first_available )) || (( ${#basedir_realpath} > ${#chosen_basedir_realpath} )) ; then
                chosen_vcs="${vcs}"
                chosen_vcs_comm=("${(kv)vcs_comm[@]}")
                chosen_backend_misc=("${(kv)backend_misc[@]}")
                chosen_basedir_realpath="${basedir_realpath}"

                (( choose_first_available )) && break
            fi
        fi
    done

    vcs="${chosen_vcs}"
    vcs_comm=("${(kv)chosen_vcs_comm[@]}")
    backend_misc=("${(kv)chosen_backend_misc[@]}")

    [ -z "${vcs}" ] && {
        vcs='-quilt-'; quiltmode='standalone'
        VCS_INFO_quilt standalone || VCS_INFO_set --nvcs
        return 0
    }

    VCS_INFO_hook "pre-get-data"
    retval=$?
    if (( retval == 1 )); then
        return 0
    elif (( retval == 2 )); then
        VCS_INFO_set --nvcs
        return 0
    fi

    VCS_INFO_get_data_${vcs} || {
        VCS_INFO_set --nvcs
        return 1
    }

    VCS_INFO_set
    return 0
}

vcs_info "$@"