--- Process functions for orgs
-- @module modpol.orgs.process

--- Call modules
-- @function modpol.orgs.call_module
-- @param module_slug Same as module name (or false to run result)
-- @param intiator Initiator for module
-- @param config Config for module
-- @param result
function modpol.orgs:call_module(module_slug, initiator, config, result, parent_id)
   
   -- first, if no slug, just run result
   -- may not be necessary if we use false as default approval_module
   if not module_slug
      and result() then
      result()
      return
   elseif not modpol.modules[module_slug] then
   -- if module doesn't exist, abort
      modpol.ocutil.log('Error in ' .. self.name .. ':call_module -> module "' .. tostring(module_slug) .. '" not found')
      return
   end

   local index = #self.processes + 1
   
   local module = modpol.modules[module_slug]

    -- first applies any relevant org policies
    -- then overrides with the config values given on input
    local new_config = {}
    if modpol.util.num_pairs(module.config) > 0 then
       for k, v in pairs(module.config) do
          new_config[k] = v
          -- overrides with org policies
          if self.policies[module_slug]
             and self.policies[module_slug][k] then
             new_config[k] = self.policies[module_slug][k]
          end
          -- overrides with input settings
          if config and config[k] then
             new_config[k] = config[k]
          end
       end
    end

    -- setting default params
    local new_process = {
        metatable = {__index = module},
        initiator = initiator,
        org = self,
        id = index,
        parent_id = parent_id,
        children = {},
        config = modpol.util.copy_table(new_config),
        data = modpol.util.copy_table(module.data),
        slug = module_slug
    }

    -- call module wrapper for modules, passes its id to child process when called
    function new_process:call_module(module_slug, initiator, config, result)
        local child_id = self.org:call_module(module_slug, initiator, config, result, self.id)
        table.insert(self.children, child_id)
    end

    setmetatable(new_process, new_process.metatable)

    self.processes[index] = new_process
    self.processes[index]:initiate(result)
    local msg = "Initiating "..module_slug..
      " process id "..index.." in org "..self.name

    return index
end



--- Get the root process of the given id
-- @function modpol.orgs.get_root_process
-- @param id
-- @return root process
function modpol.orgs:get_root_process(id)
    local process = self.processes[id]
    while (process.parent_id) do
        process = self.processes[process.parent_id]
    end
    return process
end

--- Delete the process given id, return to dashboard
-- @function modpol.orgs.delete_process
-- @param id
function modpol.orgs:delete_process(id)
    local process = self.processes[id]
    if process and process ~= "deleted" then
        -- recursively deletes any children
        if #process.children > 0 then
            for i, child_id in pairs(process.children) do
                self:delete_process(child_id)
            end
        end
        local msg = "Deleting " .. self.processes[id].slug .. " process id "..id.." in org "..self.name
        modpol.ocutil.log(msg)
        self:record(msg, self.processes[id].slug)
        self:wipe_pending_actions(id)
        -- sets process to 'deleted' in process table
        self.processes[id] = 'deleted'
    end
end


--- Delete process tree by id
-- @function modpol.orgs:delete_process_tree
-- @param id Id of process tree
function modpol.orgs:delete_process_tree(id)
    self:delete_process(self:get_root_process(id).id)
end

--- Add a new pending action
-- @function modpol.orgs:add_pending_action
-- @param process_id Process id
-- @param user User adding the action
-- @param callback
function modpol.orgs:add_pending_action(process_id, user, callback) 
    self.pending[user] = self.pending[user] or {}
    self.pending[user][process_id] = callback
    modpol.interactions.message(
       user, "New pending action in org "..self.name)
end

--- Remove a pending action
-- @function modpol.orgs:remove_pending_action
-- @param process_id Process id to be removed
-- @param user
function modpol.orgs:remove_pending_action(process_id, user) 
    if self.pending[user] then
        self.pending[user][process_id] = nil
    end
end

--- Wipe all pending actions for process
-- @function modpol.orgs:wipe_pending_actions
-- @param process_id
function modpol.orgs:wipe_pending_actions(process_id)
    for user in pairs(self.pending) do
        self.pending[user][process_id] = nil
    end
end

--- Check if there are pending actions for user
-- @function modpol.orgs:has_pending_actions
-- @param user User
-- @return True if there are pending actions for a user, false if not
function modpol.orgs:has_pending_actions(user)
    -- next() will return the next pair in a table
    -- if next() returns nil, the table is empty
    if not self.pending[user] then
        return false
    else
        if not next(self.pending[user]) then
            return false
        else 
            return true
        end
    end
end

--- Create user interaction with given process
-- @function modpol.orgs:interact
-- @param process_id
-- @param user
function modpol.orgs:interact(process_id, user)
   local process = self.processes[process_id]
   if self.pending[user] then
      local callback = self.pending[user][process_id]
      if callback and process ~= "deleted" then
         -- get data in case callback ends process
         local slug = self.processes[process_id].slug
         -- run callback
         process[callback](process, user)
         -- record org data
         local msg = "Updating "..slug..
            " process id "..process_id.." in org "..self.name
         self:record(msg, slug)
      end
   end
end