function __fish_complete_pg_database
    psql -AtqwlF \t 2>/dev/null | awk 'NF > 1 { print $1 }'
end

function __fish_complete_pg_user
    psql -Atqwc 'select usename from pg_user' template1 2>/dev/null
end

complete -c psql --no-files -a '(__fish_complete_pg_database)'


#
# General options:
#

complete -c psql -s d -l dbname -a '(__fish_complete_pg_database)'      -d "database name to connect to"
complete -c psql -s c -l command        -d "run only single command (SQL or internal) and exit"
complete -c psql -s f -l file -r        -d "execute commands from file, then exit"
complete -c psql -s l -l list           -d "list available databases, then exit"

# complete -c psql -s v -l set=, --variable=NAME=VALUE
#                                           set psql variable NAME to VALUE

complete -c psql -s X -l no-psqlrc          -d "do not read startup file (~/.psqlrc)"
complete -c psql -s 1 -l single-transaction -d "execute command file as a single transaction"
complete -c psql -l help                    -d "show this help, then exit"
complete -c psql -l version                 -d "output version information, then exit"

#
#   Input and output options:
#

complete -c psql -s a, -l echo-all           -d "echo all input from script"
complete -c psql -s e, -l echo-queries       -d "echo commands sent to server"
complete -c psql -s E, -l echo-hidden        -d "display queries that internal commands generate"
complete -c psql -s L, -l log-file           -d "send session log to file"
complete -c psql -s n, -l no-readline        -d "disable enhanced command line editing (readline)"
complete -c psql -s o, -l output             -d "send query results to file (or |pipe)"
complete -c psql -s q, -l quiet              -d "run quietly (no messages, only query output)"
complete -c psql -s s, -l single-step        -d "single-step mode (confirm each query)"
complete -c psql -s S, -l single-line        -d "single-line mode (end of line terminates SQL command)"

#
#   Output format options:
#

complete -c psql -s A, -l no-align          -d "unaligned table output mode"
complete -c psql -s H, -l html              -d "HTML table output mode"
complete -c psql -s P, -l pset              -d "set printing option VAR to ARG (see \pset command)"
complete -c psql -s t, -l tuples-only       -d "print rows only"
complete -c psql -s T, -l table-attr        -d "set HTML table tag attributes (e.g., width, border)"
complete -c psql -s x, -l expanded          -d "turn on expanded table output"
complete -c psql -s F, -l field-separator   -d "set field separator (default: '|')"
complete -c psql -s R, -l record-separator  -d "set record separator (default: newline)"


#
# Connection options
#

complete -c psql -s h -l host -a '(__fish_print_hostnames)' -d "database server host or socket directory"
complete -c psql -s p -l port -x -d "database server port"
complete -c psql -s U -l username -a '(__fish_complete_pg_user)' -d "database user name"
complete -c psql -s w -l no-password -d "never prompt for password"
complete -c psql -s W -l password -d "force password prompt (should happen automatically)"