# Generates migrations_embedded.hpp from daemon/src/store/migrations/*.sql.
#
#   cmake -DMIG_DIR=<dir> -DOUT=<file> -P embed_migrations.cmake
#
# Each NNNN_name.sql becomes a Migration{ version = NNNN, name = "NNNN_name", sql = R"..." }.
# The delimiter for the raw string literal is chosen to not collide with the file body.

file(GLOB _sql_files "${MIG_DIR}/*.sql")
list(SORT _sql_files)

set(_entries "")
foreach(_f ${_sql_files})
    get_filename_component(_stem "${_f}" NAME_WE)          # 0001_initial
    string(REGEX MATCH "^([0-9]+)_" _m "${_stem}")
    if(NOT _m)
        message(FATAL_ERROR "migration file '${_f}' does not start with NNNN_")
    endif()
    string(REGEX REPLACE "^0*([0-9]+)_.*$" "\\1" _ver "${_stem}")

    file(READ "${_f}" _body)
    # Pick a raw-string delimiter guaranteed absent from the body.
    set(_delim "MIGSQL")
    while(_body MATCHES "\\)${_delim}\"")
        set(_delim "${_delim}X")
    endwhile()

    string(APPEND _entries
        "    Migration{ ${_ver}, \"${_stem}\", R\"${_delim}(\n${_body}\n)${_delim}\" },\n")
endforeach()

list(LENGTH _sql_files _count)

set(_out "// GENERATED by embed_migrations.cmake — do not edit. Source: src/store/migrations/*.sql
#pragma once
#include <array>
#include \"store/migrations.hpp\"

namespace velox::daemon::store {

inline constexpr std::array<Migration, ${_count}> kEmbeddedMigrations = {{
${_entries}}};

}  // namespace velox::daemon::store
")

if(EXISTS "${OUT}")
    file(READ "${OUT}" _existing)
    if(_existing STREQUAL "${_out}")
        return()   # unchanged — do not rewrite, keeps the build stable
    endif()
endif()
file(WRITE "${OUT}" "${_out}")