SharedConfig.lua

--[[============================================================================
    SharedConfig.lua

    Module shared by all plugin scripts.
    Dynamically generates ExifTool configuration based on FieldDefinitions.

============================================================================--]]

local LrFileUtils = import "LrFileUtils"
local LrPathUtils = import "LrPathUtils"

local Config = require "PluginConfig"
local Fields = require "FieldDefinitions"
local Log    = require "PluginLogger"

local logger = Log.getLogger("SharedConfig")

local SC = {}

-- Re-export constants from Config (convenience)
SC.PLUGIN_ID   = Config.PLUGIN_ID
SC.XMP_NS      = Config.XMP_NS
SC.XMP_PREFIX  = Config.XMP_PREFIX
SC.FIELD_MAP   = Fields.FIELDS

--------------------------------------------------------------------------
-- ExifTool config generation from FieldDefinitions
--------------------------------------------------------------------------

function SC.writeExifToolConfig(tmpDir, configName)
    configName = configName or "custom_xmp.config"
    local configPath = LrPathUtils.child(tmpDir, configName)

    -- Header: register namespace in XMP::Main
    local lines = {
        "# Auto-generated ExifTool config from FieldDefinitions.lua",
        "%Image::ExifTool::UserDefined = (",
        "    'Image::ExifTool::XMP::Main' => {",
        "        " .. SC.XMP_PREFIX .. " => {",
        "            SubDirectory => {",
        "                TagTable => 'Image::ExifTool::UserDefined::"
            .. SC.XMP_PREFIX .. "',",
        "            },",
        "        },",
        "    },",
        ");",
        "",
        "# Tag definitions",
        "%Image::ExifTool::UserDefined::" .. SC.XMP_PREFIX .. " = (",
        "    GROUPS    => { 0 => 'XMP', 1 => 'XMP-" .. SC.XMP_PREFIX
            .. "', 2 => 'Other' },",
        "    NAMESPACE => { '" .. SC.XMP_PREFIX .. "' => '"
            .. SC.XMP_NS .. "' },",
        "    WRITABLE  => 'string',",
    }

    -- Dynamic tag list from FieldDefinitions
    for _, field in ipairs(Fields.FIELDS) do
        table.insert(lines, "    " .. field.xmpTag .. " => { },")
    end

    table.insert(lines, ");")
    table.insert(lines, "1;")
    table.insert(lines, "")

    local content = table.concat(lines, "\n")

    local f = io.open(configPath, "w")
    if not f then
        logger:error("Cannot create config: " .. configPath)
        return nil
    end
    f:write(content)
    f:close()

    if Log.isEnabled("trace") then
        logger:trace("ExifTool config written: " .. configPath)
    end

    return configPath
end

--------------------------------------------------------------------------
-- Temporary files
--------------------------------------------------------------------------

function SC.safeDelete(path)
    if path and LrFileUtils.exists(path) then
        LrFileUtils.delete(path)
    end
end

function SC.readFileContents(path)
    if not path or not LrFileUtils.exists(path) then
        return "(file does not exist)"
    end
    local f = io.open(path, "r")
    if not f then return "(cannot open)" end
    local content = f:read("*all")
    f:close()
    return content or "(empty)"
end

--------------------------------------------------------------------------
-- RAW / sidecar
--------------------------------------------------------------------------

function SC.isRawFile(filePath)
    local ext = LrPathUtils.extension(filePath)
    if not ext then return false end
    return Config.RAW_EXTENSIONS[string.lower(ext)] == true
end

function SC.getSidecarPath(filePath)
    local dir  = LrPathUtils.parent(filePath)
    local base = LrPathUtils.removeExtension(LrPathUtils.leafName(filePath))
    return LrPathUtils.child(dir, base .. ".xmp")
end

function SC.ensureSidecarExists(sidecarPath)
    if LrFileUtils.exists(sidecarPath) then
        return true
    end

    local minXmp = [[<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
<x:xmpmeta xmlns:x="adobe:ns:meta/">
 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description rdf:about=""/>
 </rdf:RDF>
</x:xmpmeta>
<?xpacket end="w"?>
]]

    local f = io.open(sidecarPath, "wb")
    if not f then
        logger:warn("Cannot create sidecar: " .. sidecarPath)
        return false
    end
    f:write(minXmp)
    f:close()

    if Log.isEnabled("trace") then
        logger:trace("Created sidecar: " .. sidecarPath)
    end
    return true
end

function SC.getTargetPath(filePath)
    if SC.isRawFile(filePath) then
        local sidecarPath = SC.getSidecarPath(filePath)
        SC.ensureSidecarExists(sidecarPath)
        return sidecarPath, true
    end
    return filePath, false
end

return SC