local PLUGIN_NAME = 'CSV Stage Builder'
local DEFAULT_FILE = 'Stage-xyz.csv'
local REPORT_FILE = 'CSV_Stage_Builder_Report.txt'

local function echo(text)
    if gma and gma.echo then
        gma.echo('[' .. PLUGIN_NAME .. '] ' .. tostring(text))
    end
end

local function feedback(text)
    echo(text)
    if gma and gma.feedback then
        gma.feedback('[' .. PLUGIN_NAME .. '] ' .. tostring(text))
    end
end

local function popup(title, text)
    feedback(text)
    if gma and gma.gui and gma.gui.msgbox then
        gma.gui.msgbox(tostring(title or PLUGIN_NAME), tostring(text or ''))
    end
end

local function trim(text)
    text = tostring(text or '')
    return (text:gsub('^%s+', ''):gsub('%s+$', ''))
end

local function normalize_filename(text)
    return trim(text):lower()
end

local function strip_bom(text)
    return tostring(text or ''):gsub('^\239\187\191', '')
end

local function normalize_header(text)
    text = trim(text):lower()
    text = text:gsub('/.*$', '')
    text = text:gsub('[%s_%-%(%)]', '')
    return text
end

local function count_char(text, char)
    local _, count = tostring(text or ''):gsub('%' .. char, '')
    return count
end

local function detect_delimiter(line)
    local comma = count_char(line, ',')
    local semicolon = count_char(line, ';')
    local tab = count_char(line, '\t')
    if tab >= comma and tab >= semicolon and tab > 0 then
        return '\t'
    end
    if semicolon > comma then
        return ';'
    end
    return ','
end

local function split_csv_line(line, delimiter)
    local fields = {}
    local field = ''
    local in_quotes = false
    local i = 1
    line = tostring(line or '')
    while i <= #line do
        local char = line:sub(i, i)
        if char == '"' then
            if in_quotes and line:sub(i + 1, i + 1) == '"' then
                field = field .. '"'
                i = i + 1
            else
                in_quotes = not in_quotes
            end
        elseif char == delimiter and not in_quotes then
            fields[#fields + 1] = trim(field)
            field = ''
        else
            field = field .. char
        end
        i = i + 1
    end
    fields[#fields + 1] = trim(field)
    return fields
end

local function parse_number(value)
    value = trim(value)
    value = value:gsub(',', '.')
    value = value:gsub('[mM]$', '')
    value = trim(value)
    return tonumber(value)
end

local function parse_fixture_id(value)
    value = trim(value)
    value = value:gsub('^[Ff][Ii][Xx][Tt][Uu][Rr][Ee]%s+', '')
    value = value:gsub('^[Ff][Ii][Xx]%s+', '')
    value = trim(value)
    if value:match('^%d+%.?%d*$') then
        return value
    end
    return nil
end

local function build_import_path()
    local base = ''
    if gma and gma.show and gma.show.getvar then
        base = gma.show.getvar('PATH') or ''
    end
    if base == '' then
        return ''
    end
    return base .. '/importexport/'
end

local function file_exists(path)
    local file = io.open(path, 'r')
    if file then
        file:close()
        return true
    end
    return false
end

local function resolve_csv_path(filename)
    filename = trim(filename)
    if filename == '' then
        return nil
    end
    local import_path = build_import_path()
    local candidates = {}
    candidates[#candidates + 1] = import_path .. filename
    if not filename:lower():match('%.csv$') then
        candidates[#candidates + 1] = import_path .. filename .. '.csv'
    end
    candidates[#candidates + 1] = filename
    if not filename:lower():match('%.csv$') then
        candidates[#candidates + 1] = filename .. '.csv'
    end
    for _, path in ipairs(candidates) do
        if file_exists(path) then
            return path, import_path
        end
    end
    return nil, import_path
end

local function header_index(headers)
    local map = {}
    for index, value in ipairs(headers) do
        local key = normalize_header(value)
        if key == 'fixture' or key == 'fixtureid' or key == 'fid' or key == 'id' or key == 'no' or key == 'number' then
            map.fixture = index
        elseif key == 'x' or key == 'xm' or key == 'xmeter' or key == 'xmetre' or key == 'posx' or key == 'posxm' or key == 'positionx' or key == 'stagex' then
            map.x = index
        elseif key == 'y' or key == 'ym' or key == 'ymeter' or key == 'ymetre' or key == 'posy' or key == 'posym' or key == 'positiony' or key == 'stagey' then
            map.y = index
        elseif key == 'z' or key == 'zm' or key == 'zmeter' or key == 'zmetre' or key == 'posz' or key == 'poszm' or key == 'positionz' or key == 'stagez' then
            map.z = index
        elseif key == 'rx' or key == 'rxdeg' or key == 'rotx' or key == 'rotxdeg' or key == 'rotatex' or key == 'rotatexdeg' or key == 'rotationx' or key == 'rotationxdeg' or key == 'stagerotx' then
            map.rx = index
        elseif key == 'ry' or key == 'rydeg' or key == 'roty' or key == 'rotydeg' or key == 'rotatey' or key == 'rotateydeg' or key == 'rotationy' or key == 'rotationydeg' or key == 'stageroty' then
            map.ry = index
        elseif key == 'rz' or key == 'rzdeg' or key == 'rotz' or key == 'rotzdeg' or key == 'rotatez' or key == 'rotatezdeg' or key == 'rotationz' or key == 'rotationzdeg' or key == 'stagerotz' then
            map.rz = index
        end
    end
    if map.fixture and map.x and map.y and map.z then
        return map
    end
    return nil
end

local function read_csv(path)
    local file = io.open(path, 'r')
    if not file then
        return nil, 'Cannot open CSV: ' .. tostring(path)
    end

    local lines = {}
    for line in file:lines() do
        line = strip_bom(line)
        if trim(line) ~= '' and not trim(line):match('^#') then
            lines[#lines + 1] = line
        end
    end
    file:close()

    if #lines == 0 then
        return nil, 'CSV is empty'
    end

    local delimiter = detect_delimiter(lines[1])
    local first = split_csv_line(lines[1], delimiter)
    local map = header_index(first)
    local start_line = 1
    if map then
        start_line = 2
    else
        map = {fixture = 1, x = 2, y = 3, z = 4}
    end

    local rows = {}
    local errors = {}
    for line_number = start_line, #lines do
        local fields = split_csv_line(lines[line_number], delimiter)
        local fixture_id = parse_fixture_id(fields[map.fixture])
        local x = parse_number(fields[map.x])
        local y = parse_number(fields[map.y])
        local z = parse_number(fields[map.z])
        local has_rotation_columns = map.rx or map.ry or map.rz
        local rx = map.rx and parse_number(fields[map.rx]) or nil
        local ry = map.ry and parse_number(fields[map.ry]) or nil
        local rz = map.rz and parse_number(fields[map.rz]) or nil
        if fixture_id and x and y and z then
            local row = {line = line_number, fixture_id = fixture_id, x = x, y = y, z = z}
            if rx and ry and rz then
                row.rx = rx
                row.ry = ry
                row.rz = rz
                row.has_rotation = true
            elseif has_rotation_columns then
                errors[#errors + 1] = 'Line ' .. line_number .. ' rotation skipped: need RotX,RotY,RotZ'
            end
            rows[#rows + 1] = row
        else
            errors[#errors + 1] = 'Line ' .. line_number .. ' skipped: need FixtureID,X,Y,Z'
        end
    end

    return rows, nil, errors
end

local function format_number(value)
    local text = string.format('%.4f', value)
    text = text:gsub('0+$', '')
    text = text:gsub('%.$', '')
    if text == '-0' then
        text = '0'
    end
    return text
end

local function safe_cmd(command)
    feedback(command)
    gma.cmd(command)
end

local function write_report(import_path, source_path, scale, rows, errors)
    if import_path == '' then
        return
    end
    local path = import_path .. REPORT_FILE
    local file = io.open(path, 'w')
    if not file then
        return
    end
    file:write(PLUGIN_NAME .. '\n')
    file:write('Source: ' .. tostring(source_path) .. '\n')
    file:write('Scale: ' .. tostring(scale) .. '\n')
    file:write('Applied rows: ' .. tostring(#rows) .. '\n')
    file:write('Skipped rows: ' .. tostring(#errors) .. '\n\n')
    for _, row in ipairs(rows) do
        local rotation = ''
        if row.has_rotation then
            rotation = ' rotate ' .. row.rx .. ', ' .. row.ry .. ', ' .. row.rz
        end
        file:write('Fixture ' .. row.fixture_id .. ' -> ' .. row.x .. ', ' .. row.y .. ', ' .. row.z .. rotation .. '\n')
    end
    if #errors > 0 then
        file:write('\nErrors:\n')
        for _, message in ipairs(errors) do
            file:write(message .. '\n')
        end
    end
    file:close()
end

local function run()
    local last_file = ''
    if gma and gma.show and gma.show.getvar then
        last_file = gma.show.getvar('CSVStageBuilderFile') or ''
    end
    local normalized_last_file = normalize_filename(last_file)
    if last_file == '' or normalized_last_file == 'stage_xyz_template.csv' then
        last_file = DEFAULT_FILE
    end

    local filename = gma.textinput('CSV file in gma2/importexport', last_file)
    if not filename then
        feedback('Canceled')
        return
    end
    filename = trim(filename)
    if filename == '' then
        popup('CSV Stage Builder', 'Canceled: empty filename')
        return
    end

    local scale_text = gma.textinput('Scale factor (1 = use CSV values unchanged)', '1')
    if not scale_text then
        feedback('Canceled')
        return
    end
    local scale = parse_number(scale_text) or 1

    local path, import_path = resolve_csv_path(filename)
    if not path then
        popup('CSV not found', 'Cannot find "' .. filename .. '". Put the CSV in:\n' .. import_path .. '\n\nCSV header should be:\nFixtureID,X,Y,Z')
        return
    end

    local rows, err, errors = read_csv(path)
    errors = errors or {}
    if err then
        popup('CSV error', err)
        return
    end
    if #rows == 0 then
        popup('No valid rows', 'No valid rows found in:\n' .. path .. '\n\nCSV header should be:\nFixtureID,X,Y,Z')
        write_report(import_path, path, scale, rows, errors)
        return
    end

    if gma and gma.show and gma.show.setvar then
        gma.show.setvar('CSVStageBuilderFile', filename)
    end

    feedback('Applying ' .. tostring(#rows) .. ' fixture positions')
    safe_cmd('ClearSelection')
    for _, row in ipairs(rows) do
        local x = format_number(row.x * scale)
        local y = format_number(row.y * scale)
        local z = format_number(row.z * scale)
        safe_cmd('Fixture ' .. row.fixture_id)
        safe_cmd('Move3D At ' .. x .. ' ' .. y .. ' ' .. z)
        if row.has_rotation then
            local rx = format_number(row.rx)
            local ry = format_number(row.ry)
            local rz = format_number(row.rz)
            safe_cmd('Rotate3D At ' .. rx .. ' ' .. ry .. ' ' .. rz)
        end
        safe_cmd('ClearSelection')
    end

    write_report(import_path, path, scale, rows, errors)
    popup('CSV Stage Builder Done', 'Applied ' .. tostring(#rows) .. ' fixture positions.\nSkipped ' .. tostring(#errors) .. ' rows.\n\nScale factor: ' .. tostring(scale) .. '\nSource:\n' .. path)
end

return run