-- osm2pgsql Flex output script for Transportationer
-- Maps OSM tags to the 5 POI categories

-- Write to a per-city staging table so osm2pgsql can freely drop/recreate it
-- in create mode without touching other cities' rows in raw_pois.
-- extract-pois.ts merges the staging data into raw_pois after the import.
local city_slug = os.getenv('CITY_SLUG') or 'unknown'
local staging_name = 'raw_pois_import_' .. city_slug:gsub('[^%w]', '_')

local pois = osm2pgsql.define_table({
    name = staging_name,
    ids = { type = 'any', id_column = 'osm_id', type_column = 'osm_type' },
    columns = {
        { column = 'city_slug',   type = 'text' },
        { column = 'category',    type = 'text' },
        { column = 'subcategory', type = 'text' },
        { column = 'name',        type = 'text' },
        { column = 'tags',        type = 'jsonb' },
        { column = 'geom',        type = 'point', projection = 4326 },
    }
})

-- Tag → {category, subcategory} mapping
local tag_map = {
    amenity = {
        -- service_trade
        pharmacy        = { 'service_trade',     'pharmacy' },
        bank            = { 'service_trade',     'bank' },
        atm             = { 'service_trade',     'atm' },
        cafe            = { 'service_trade',     'cafe' },
        restaurant      = { 'service_trade',     'restaurant' },
        fast_food       = { 'service_trade',     'restaurant' },
        post_office     = { 'service_trade',     'post_office' },
        marketplace     = { 'service_trade',     'market' },
        -- transport
        bicycle_rental  = { 'transport',         'bike_share' },
        car_sharing     = { 'transport',         'car_share' },
        ferry_terminal  = { 'transport',         'ferry' },
        bus_station     = { 'transport',         'bus_stop' },
        -- work_school
        kindergarten    = { 'work_school',       'kindergarten' },
        childcare       = { 'work_school',       'kindergarten' },
        school          = { 'work_school',       'school' },
        university      = { 'work_school',       'university' },
        college         = { 'work_school',       'university' },
        driving_school  = { 'work_school',       'driving_school' },
        -- culture_community
        library         = { 'culture_community', 'library' },
        theatre         = { 'culture_community', 'theatre' },
        cinema          = { 'culture_community', 'theatre' },
        community_centre= { 'culture_community', 'community_center' },
        place_of_worship= { 'culture_community', 'place_of_worship' },
        hospital        = { 'culture_community', 'hospital' },
        clinic          = { 'culture_community', 'clinic' },
        doctors         = { 'culture_community', 'clinic' },
        social_facility = { 'culture_community', 'social_services' },
        townhall        = { 'culture_community', 'government' },
        police          = { 'culture_community', 'government' },
        -- recreation
        swimming_pool   = { 'recreation',        'swimming_pool' },
    },
    shop = {
        supermarket     = { 'service_trade', 'supermarket' },
        wholesale       = { 'service_trade', 'supermarket' },
        convenience     = { 'service_trade', 'convenience' },
        bakery          = { 'service_trade', 'cafe' },
        pharmacy        = { 'service_trade', 'pharmacy' },
        laundry         = { 'service_trade', 'laundry' },
        dry_cleaning    = { 'service_trade', 'laundry' },
        greengrocer     = { 'service_trade', 'market' },
        butcher         = { 'service_trade', 'market' },
        department_store= { 'service_trade', 'market' },
        mall            = { 'service_trade', 'market' },
    },
    highway = {
        bus_stop        = { 'transport', 'bus_stop' },
    },
    railway = {
        station         = { 'transport', 'train_station' },
        halt            = { 'transport', 'train_station' },
        tram_stop       = { 'transport', 'tram_stop' },
        subway_entrance = { 'transport', 'metro' },
        subway_station  = { 'transport', 'metro' },
    },
    -- public_transport stop_position/platform intentionally excluded:
    -- they duplicate highway=bus_stop / railway=tram_stop nodes at the same
    -- physical location and would double-count those stops in scoring.
    office = {
        coworking       = { 'work_school', 'coworking' },
    },
    tourism = {
        museum          = { 'culture_community', 'museum' },
    },
    leisure = {
        park            = { 'recreation', 'park' },
        playground      = { 'recreation', 'playground' },
        sports_centre   = { 'recreation', 'sports_facility' },
        fitness_centre  = { 'recreation', 'gym' },
        swimming_pool   = { 'recreation', 'swimming_pool' },
        garden          = { 'recreation', 'park' },
        nature_reserve  = { 'recreation', 'green_space' },
        golf_course     = { 'recreation', 'green_space' },
        pitch           = { 'recreation', 'sports_facility' },
        arts_centre     = { 'culture_community', 'community_center' },
    },
    landuse = {
        recreation_ground = { 'recreation', 'green_space' },
        grass           = { 'recreation',   'green_space' },
        meadow          = { 'recreation',   'green_space' },
        forest          = { 'recreation',   'green_space' },
    },
}

local CITY_SLUG = city_slug

local function classify(tags)
    for key, values in pairs(tag_map) do
        local val = tags[key]
        if val and values[val] then
            return values[val][1], values[val][2]
        end
    end
    return nil, nil
end

local function get_centroid(object)
    if object.type == 'node' then
        return object:as_point()
    elseif object.type == 'way' then
        local geom = object:as_linestring()
        if geom then return geom:centroid() end
    else
        local geom = object:as_multipolygon()
        if geom then return geom:centroid() end
    end
    return nil
end

local function process(object)
    local category, subcategory = classify(object.tags)
    if not category then return end
    local geom = get_centroid(object)
    if not geom then return end
    pois:insert({
        city_slug   = CITY_SLUG,
        category    = category,
        subcategory = subcategory,
        name        = object.tags.name,
        tags        = object.tags,
        geom        = geom,
    })
end

function osm2pgsql.process_node(object)     process(object) end
function osm2pgsql.process_way(object)      process(object) end
function osm2pgsql.process_relation(object) process(object) end