-- ===================================================================
-- /orgs.lua
-- Org-related functions for Modular Politics
-- Called by modpol/modpol/api.lua

-- ===================================================================
-- Function: modpol.record
-- Params: strings msg, org
-- Outputs:
-- "msg" specifies an event and/or status message.
-- "org" specifies an "org" name.
-- This  function adds  the message to a  global ledger  and, if "org"
-- specifies a valid "org", to an "org"-specific ledger. Both the mem-
-- ory-resident and on-disk copies of the data structures used are up-
-- dated.

modpol.record = function (org_name, msg)
                                -- Record in global ledger
   table.insert (modpol.ledger, msg)
                                -- Record in "org"-specific ledger
   if modpol.orgs [org_name] ~= nil then
        local org_ledger =  modpol.orgs [org_name]["ledger"]
        if    org_ledger == nil then
            modpol.orgs [org_name]["ledger"] = { msg }
        else
            modpol.orgs [org_name]["ledger"] =
                table.insert (org_ledger, msg)
        end
    end

    modpol.store_data()         -- Copy data to disk
end

-- ===================================================================
-- Function: modpol.add_org
-- Params:   string name, table members
-- Output:
--
-- This function creates an "org".  It returns either an error message
-- starting with "-!-" or a success message.
--
-- The string parameter specifies the "org" name.
--
-- The  specified table should  be an  integer-indexed array of member
-- names.

modpol.add_org = function (org_name, members)
    local str

    if modpol.ocutil.str_empty (org_name) then
        return "Error: Org needs a name"
    end

    modpol.ocutil.log ("Adding org " .. org_name)
    if modpol.orgs [org_name] ~= nil then
        str = "Error: Org " .. org_name .. " already exists"
        modpol.ocutil.log (str)
        return str
    end

    modpol.orgs [org_name] = { members=members }
    local msg = "New org: " .. org_name ..
        " (" .. table.concat (members, ", ") .. ")"

   modpol.record (org_name, msg)
   return msg
end

-- ===================================================================
-- Function: modpol.list_orgs
-- Params:   None
-- Output:
-- This function returns a text-format list of "orgs".  The list shows
-- one "org" per line in the following format:
-- org_name (member, member, ...)
-- If there are no "orgs", the output is an empty string.

modpol.list_orgs  = function()
    local outbuf = ""
    local str
    for org_name, org_data in pairs (modpol.orgs) do
                                -- Process next "org"
                                -- Build string version of member list
        local memcat = org_data ["members"]
        if  modpol.ocutil.str_empty (memcat) then
              memcat = "(empty)"
        else
              memcat = "(" .. table.concat (memcat, ", ") .. ")"
        end
                                -- Build output string
        outbuf = outbuf .. org_name .. " " .. memcat .. "\n"
    end
    return outbuf
end

-- ===================================================================
-- Function: modpol.reset_orgs
-- Params:   None
-- Removes all orgs and recreates blank org "instance" with all
-- current users
-- returns confirmation message

modpol.reset_orgs = function()
   local users = modpol.list_users()
   modpol.orgs = {}
   local message = "Orgs purged"
   modpol.record(nil, message)
   modpol.add_org("instance", users)
   return message
end

-- ===================================================================
-- Function: modpol.add_member
-- Params: org (string), member (string)
-- Output:
-- Adds the specified member to the specified org
-- Returns confirmation or error message

modpol.add_member = function(org, member)
   if (modpol.orgs[org] == nil) then
      return "Error: No such org"
   else
      if modpol.is_member(org,member) then
         return "Error: " .. member .. " is already a member of " .. org
      else
         table.insert(modpol.orgs[org]["members"], member)
         local message = member .. " added to org " .. org
         modpol.record(message, org)
         return message
      end
   end
end

-- ===================================================================
-- Function: modpol.is_member
-- Params: org (string), member (string)
-- Output: Boolean depending on membership or nil/error message

modpol.is_member = function(org, member)
   if (modpol.orgs[org] == nil) then
      return nil, "Error: No such org"
   else
      local member_table = modpol.orgs[org]["members"]
      if member_table then
         for index, value in pairs(member_table) do
            if value == member then
               -- match found
               return true
            end
         end
         -- no match found
         return false
      end
      return false      
   end
end

-- ===================================================================
-- Function: modpol.remove_member
-- Params: org (string), member (string)
-- Output:
-- Removes the specified member from the specified org
-- Returns confirmation or error message

function modpol.remove_member(org, member)
   local message = "Error: No such org"
   if (modpol.orgs[org] == nil) then
      return nil, message
   else
      local member_table = modpol.orgs[org]["members"]
      if member_table then
         for index, value in pairs(member_table) do
            if value == member then
               -- match found, set to nil
               value = nil               
               message = member .. " removed from org " .. org
               return message
            end
         end
      end
      -- no match found (or org has no members)
      message = member .. " not found in org " .. org
      return nil, message
   end
end

-- ===================================================================
-- TKTK
-- rename_org(old_name, new_name)
-- Renames an org 

-- ===================================================================
-- modpol.add_policy
-- Adds a policy to an org's [org].policies table
-- Params: org_name (string), target_function (string),
-- policy_function (string)
-- function names should be in the form [module?.][function]
-- and can be modpol.delegate(org_name)
-- Output: true if successful, nil if error
modpol.add_policy = function(org_name, target_function, policy_function)
   -- first, basic checks
   local message = "Error: No such org"
   if (modpol.orgs[org_name] == nil) then
      return nil, message
   elseif (modpol[target_function] == nil) then
      message = "Error: No such target function"
      return nil, message
   elseif (modpol[policy_function]) then
      message = "Error: No such policy function"
      return nil, message
   else
      -- okay, proceed
      modpol.orgs[org_name].policies[target_function] = policy_function
      message = "In org " .. org_name .. ", policy for " .. target_function
         .. " set to " .. policy_function
      record(org_name, message)
      return true, message
   end
end

-- ===================================================================
-- End of file.