obs = obslua

----------------------------------------------------------------
-- GLOBAL SETTINGS (DEFAULTS)
----------------------------------------------------------------
local settings = {
    -- OBS text source settings
    text_source_name        = "",
    prefix                  = "Next Stream",
    separator               = " | ",
    suffix                  = "",
    time_format             = "24h",    -- "24h" or "12h"
    day_format              = "full",   -- "full"=Monday, "short"=Mon
    max_streams_displayed   = 1,
    even_week_time          = "20:00",  -- For even ISO weeks
    odd_week_time           = "21:00",  -- For odd ISO weeks
    category_display_mode   = "show",   -- "show", "show_round", "show_square", "hide"

    -- File output settings
    file_path                  = "",
    file_use_emojis            = true,
    file_show_category         = true,
    file_max_streams_displayed = 1,
    file_separator             = " | ",
    file_multiline             = false, -- Each stream on a new line if true

    -- Day-specific settings
    days = {
        {enabled = true,  auto_time = true,  custom_time = "", category = ""}, -- Monday
        {enabled = false, auto_time = true,  custom_time = "", category = ""},
        {enabled = false, auto_time = true,  custom_time = "", category = ""},
        {enabled = false, auto_time = true,  custom_time = "", category = ""},
        {enabled = false, auto_time = true,  custom_time = "", category = ""},
        {enabled = false, auto_time = true,  custom_time = "", category = ""},
        {enabled = false, auto_time = true,  custom_time = "", category = ""}
    }
}

----------------------------------------------------------------
-- 1) ISO-8601 WEEK CALCULATION (THURSDAY RULE)
----------------------------------------------------------------
local function get_iso_week_number(day_offset)
    local offset_secs = (day_offset or 0) * 24 * 60 * 60
    local offset_time = os.time() + offset_secs
    local wday = tonumber(os.date("%u", offset_time))  -- Monday=1, Sunday=7
    local thursday = offset_time + (4 - wday) * 24 * 60 * 60
    local year_of_thursday = os.date("%Y", thursday)
    local jan1 = os.time{year = year_of_thursday, month = 1, day = 1}
    local diff_in_days = math.floor((thursday - jan1) / (24 * 60 * 60))
    return math.floor(diff_in_days / 7) + 1
end

local function is_even_week(week_num)
    return (week_num % 2 == 0)
end

----------------------------------------------------------------
-- 2) TIME PARSING & FORMATTING
--    Detects AM/PM (e.g. "8 AM", "8 PM") and converts to 24h for internal use.
--    Then formats output as 24h or 12h, depending on settings.time_format.
----------------------------------------------------------------
local function parse_time(chosen_time)
    if not chosen_time then return 0, 0 end
    local s = chosen_time:lower()

    -- Detect AM/PM
    local is_am = s:find("am")
    local is_pm = s:find("pm")

    -- Strip non-digit characters except ":" to isolate hours/minutes
    local stripped = s:gsub("[^%d:]", "")
    local h, m = stripped:match("^(%d+):?(%d*)$")
    local hours   = tonumber(h) or 0
    local minutes = tonumber(m) or 0

    -- Convert to 24-hour internally
    if is_am and hours == 12 then
        hours = 0
    elseif is_pm and hours < 12 then
        hours = hours + 12
    end

    return hours, minutes
end

local function format_time_24h(hours, minutes)
    return string.format("%02d:%02d", hours, minutes)
end

local function format_time_12h(hours, minutes)
    local suffix = "AM"
    local h = hours
    if h == 0 then
        h = 12
        suffix = "AM"
    elseif h == 12 then
        suffix = "PM"
    elseif h > 12 then
        h = h - 12
        suffix = "PM"
    end
    return string.format("%d:%02d %s", h, minutes, suffix)
end

local function convert_time_for_display(hours, minutes)
    if settings.time_format == "12h" then
        return format_time_12h(hours, minutes)
    else
        return format_time_24h(hours, minutes)
    end
end

----------------------------------------------------------------
-- 3) WRAPPING CATEGORY
--    The txt file follows exactly the same brackets as OBS,
--    except if category_display_mode is "show" or "hide".
----------------------------------------------------------------
local function wrap_category(cat, mode)
    if cat == nil or cat == "" then
        return ""
    end
    if mode == "hide" then
        return ""
    elseif mode == "show" then
        return cat
    elseif mode == "show_round" then
        return "(" .. cat .. ")"
    elseif mode == "show_square" then
        return "[" .. cat .. "]"
    end
    return cat
end

----------------------------------------------------------------
-- 4) COLLECT UPCOMING STREAMS FOR OBS
----------------------------------------------------------------
local function get_upcoming_streams_obs()
    local results = {}
    local days_full  = {"Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"}
    local days_short = {"Mon","Tue","Wed","Thu","Fri","Sat","Sun"}
    local day_labels = (settings.day_format == "full") and days_full or days_short

    local now = os.time()
    local today_idx = (os.date("*t").wday + 5) % 7 + 1
    local found_count = 0
    local max_count = settings.max_streams_displayed

    for offset = 0, 13 do
        local idx = (today_idx + offset - 1) % 7 + 1
        local day_conf = settings.days[idx]
        if day_conf.enabled then
            local w_num = get_iso_week_number(offset)
            local is_e  = is_even_week(w_num)

            local chosen_time = day_conf.auto_time
                               and (is_e and settings.even_week_time or settings.odd_week_time)
                               or  day_conf.custom_time

            -- Convert & format
            local hours, minutes = parse_time(chosen_time)
            local display_time   = convert_time_for_display(hours, minutes)
            local stream_time    = os.time{
                year  = os.date("%Y", now),
                month = os.date("%m", now),
                day   = os.date("%d", now) + offset,
                hour  = hours,
                min   = minutes
            }

            if stream_time > now then
                local day_name
                if offset == 0 then
                    day_name = "Today"
                elseif offset == 1 then
                    day_name = "Tomorrow"
                else
                    day_name = day_labels[idx]
                end

                local cat_wrapped = wrap_category(day_conf.category, settings.category_display_mode)
                local line
                if cat_wrapped == "" then
                    line = day_name .. settings.separator .. display_time .. " " .. settings.suffix
                else
                    line = day_name .. settings.separator ..
                           cat_wrapped .. settings.separator ..
                           display_time .. " " .. settings.suffix
                end

                table.insert(results, line)
                found_count = found_count + 1
                if found_count >= max_count then
                    break
                end
            end
        end
    end
    return results
end

----------------------------------------------------------------
-- 5) COLLECT UPCOMING STREAMS FOR FILE
--    The bracket style also follows OBS mode:
--      - "show_round" => (cat)
--      - "show_square" => [cat]
--      - "show" => cat with no brackets
--      - "hide" => skip category
----------------------------------------------------------------
local function get_upcoming_streams_file()
    local results = {}
    local now = os.time()
    local today_idx = (os.date("*t").wday + 5) % 7 + 1
    local found_count = 0
    local max_count = settings.file_max_streams_displayed

    for offset = 0, 13 do
        local idx = (today_idx + offset - 1) % 7 + 1
        local day_conf = settings.days[idx]
        if day_conf.enabled then
            local w_num = get_iso_week_number(offset)
            local is_e  = is_even_week(w_num)

            local chosen_time = day_conf.auto_time
                               and (is_e and settings.even_week_time or settings.odd_week_time)
                               or  day_conf.custom_time

            local hours, minutes = parse_time(chosen_time)
            local display_time   = convert_time_for_display(hours, minutes)
            local stream_time    = os.time{
                year  = os.date("%Y", now),
                month = os.date("%m", now),
                day   = os.date("%d", now) + offset,
                hour  = hours,
                min   = minutes
            }

            if stream_time > now then
                local day_name = os.date("%A", stream_time)
                if offset == 0 then
                    day_name = "Today"
                elseif offset == 1 then
                    day_name = "Tomorrow"
                end

                local cat_wrapped = ""
                if settings.file_show_category then
                    cat_wrapped = wrap_category(day_conf.category, settings.category_display_mode)
                end

                local line
                if cat_wrapped == "" then
                    line = day_name .. " " .. display_time
                else
                    line = day_name .. " " .. cat_wrapped .. " " .. display_time
                end

                if settings.file_use_emojis then
                    -- Replace first space with " ⏰ " to mimic the sample
                    line = "📅 " .. line:gsub(" ", " ⏰ ", 1)
                end

                table.insert(results, line)
                found_count = found_count + 1
                if found_count >= max_count then
                    break
                end
            end
        end
    end
    return results
end

----------------------------------------------------------------
-- 6) UPDATE OBS TEXT SOURCE & OVERWRITE .TXT
----------------------------------------------------------------
local function update_text_source()
    -- OBS text
    local obs_streams = get_upcoming_streams_obs()
    local text_output
    if #obs_streams == 0 then
        text_output = "No stream scheduled"
    else
        -- German script style: prefix + "\n" + lines
        text_output = settings.prefix .. "\n" .. table.concat(obs_streams, "\n")
    end

    local source = obs.obs_get_source_by_name(settings.text_source_name)
    if source then
        local src_settings = obs.obs_source_get_settings(source)
        obs.obs_data_set_string(src_settings, "text", text_output)
        obs.obs_source_update(source, src_settings)
        obs.obs_data_release(src_settings)
        obs.obs_source_release(source)
    end

    -- File output
    if settings.file_path == "" then
        return
    end

    local file_streams = get_upcoming_streams_file()
    local file_content
    if #file_streams == 0 then
        file_content = "No stream scheduled"
    else
        if settings.file_multiline then
            file_content = table.concat(file_streams, "\n")
        else
            file_content = table.concat(file_streams, settings.file_separator)
        end
    end

    local f = io.open(settings.file_path, "w")
    if f then
        f:write(file_content)
        f:close()
    else
        obs.script_log(obs.LOG_WARNING, "Failed to open file: " .. settings.file_path)
    end
end

----------------------------------------------------------------
-- 7) OBS SCRIPT PROPERTIES
--    We remove the user-settable update interval to enforce 60s.
----------------------------------------------------------------
local function add_text_sources(property)
    obs.obs_property_list_add_string(property, "No text source selected", "")
    local all_sources = obs.obs_enum_sources()
    if all_sources then
        for _, s in ipairs(all_sources) do
            local source_id = obs.obs_source_get_unversioned_id(s)
            if source_id == "text_gdiplus" or source_id == "text_ft2_source" then
                local name = obs.obs_source_get_name(s)
                obs.obs_property_list_add_string(property, name, name)
            end
        end
        obs.source_list_release(all_sources)
    end
end

function script_properties()
    local props = obs.obs_properties_create()

    ----------------------------------------------------------------
    -- (1) 📝 SELECT TEXT SOURCE
    ----------------------------------------------------------------
    local group_source = obs.obs_properties_create()
    local src_prop = obs.obs_properties_add_list(
        group_source,
        "text_source_name",
        "Select Text Source",
        obs.OBS_COMBO_TYPE_LIST,
        obs.OBS_COMBO_FORMAT_STRING
    )
    add_text_sources(src_prop)
    obs.obs_properties_add_group(props, "text_source_group", "📝 Select Text Source", obs.OBS_GROUP_NORMAL, group_source)

    ----------------------------------------------------------------
    -- (2) 🎨 FORMAT SETTINGS (FOR OBS)
    ----------------------------------------------------------------
    local format_group = obs.obs_properties_create()
    obs.obs_properties_add_text(format_group, "prefix",     "Prefix",    obs.OBS_TEXT_DEFAULT)
    obs.obs_properties_add_text(format_group, "separator",  "Separator", obs.OBS_TEXT_DEFAULT)
    obs.obs_properties_add_text(format_group, "suffix",     "Suffix",    obs.OBS_TEXT_DEFAULT)

    local df = obs.obs_properties_add_list(
        format_group,
        "day_format",
        "Day Format",
        obs.OBS_COMBO_TYPE_LIST,
        obs.OBS_COMBO_FORMAT_STRING
    )
    obs.obs_property_list_add_string(df, "Full (Monday)", "full")
    obs.obs_property_list_add_string(df, "Short (Mon)",   "short")

    local tf = obs.obs_properties_add_list(
        format_group,
        "time_format",
        "Time Format",
        obs.OBS_COMBO_TYPE_LIST,
        obs.OBS_COMBO_FORMAT_STRING
    )
    obs.obs_property_list_add_string(tf, "24-hour",         "24h")
    obs.obs_property_list_add_string(tf, "12-hour (AM/PM)", "12h")

    obs.obs_properties_add_int(format_group, "max_streams_displayed", "How many streams to display (OBS)", 1, 14, 1)

    local cat_mode = obs.obs_properties_add_list(
        format_group,
        "category_display_mode",
        "Category Display (OBS)",
        obs.OBS_COMBO_TYPE_LIST,
        obs.OBS_COMBO_FORMAT_STRING
    )
    obs.obs_property_list_add_string(cat_mode, "Show",         "show")
    obs.obs_property_list_add_string(cat_mode, "Show in ( )",  "show_round")
    obs.obs_property_list_add_string(cat_mode, "Show in [ ]",  "show_square")
    obs.obs_property_list_add_string(cat_mode, "Hide",         "hide")

    obs.obs_properties_add_group(props, "format_settings_group", "🎨 Format Settings (OBS)", obs.OBS_GROUP_NORMAL, format_group)

    ----------------------------------------------------------------
    -- (3) 🕒 STREAM START SETTINGS
    --     (Automatic detection of "AM"/"PM" is handled in parse_time)
    ----------------------------------------------------------------
    local sgroup = obs.obs_properties_create()
    obs.obs_properties_add_text(sgroup, "even_week_time", "Even Week Start", obs.OBS_TEXT_DEFAULT)
    obs.obs_properties_add_text(sgroup, "odd_week_time",  "Odd Week Start",  obs.OBS_TEXT_DEFAULT)
    obs.obs_properties_add_group(props, "stream_times", "🕒 Stream Start Settings", obs.OBS_GROUP_NORMAL, sgroup)

    ----------------------------------------------------------------
    -- (4) 📂 FILE OUTPUT SETTINGS
    ----------------------------------------------------------------
    local file_group = obs.obs_properties_create()
    local fp = obs.obs_properties_add_path(
        file_group,
        "file_path",
        "Overwrite .txt File",
        obs.OBS_PATH_FILE_SAVE,
        "*.txt",
        nil
    )
    obs.obs_property_set_long_description(fp, "Export upcoming streams to a .txt file.")

    obs.obs_properties_add_bool(file_group, "file_use_emojis",      "Use Emojis in File?")
    obs.obs_properties_add_bool(file_group, "file_show_category",   "Show Category in File?")
    obs.obs_properties_add_int(file_group,  "file_max_streams_displayed", "How many streams to display (File)", 1, 14, 1)
    obs.obs_properties_add_text(file_group, "file_separator",       "File Separator", obs.OBS_TEXT_DEFAULT)
    obs.obs_properties_add_bool(file_group, "file_multiline",       "Write each stream on a new line?")

    obs.obs_properties_add_group(props, "file_settings_group", "📂 File Output Settings", obs.OBS_GROUP_NORMAL, file_group)

    ----------------------------------------------------------------
    -- (5) 🗓️ WEEKDAY SETTINGS
    ----------------------------------------------------------------
    local day_names = {"Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"}
    for i, day in ipairs(day_names) do
        local day_group = obs.obs_properties_create()

        obs.obs_properties_add_bool(day_group, day:lower() .. "_enabled", "Enable " .. day)

        local time_choice = obs.obs_properties_add_list(
            day_group,
            day:lower() .. "_time_choice",
            "Stream Time Choice",
            obs.OBS_COMBO_TYPE_LIST,
            obs.OBS_COMBO_FORMAT_STRING
        )
        obs.obs_property_list_add_string(time_choice, "Automatic (Even/Odd Week)", "auto")
        obs.obs_property_list_add_string(time_choice, "Manual", "custom")

        obs.obs_properties_add_text(day_group, day:lower() .. "_custom_time", "Manual Time (HH:MM / 8 AM / 8 PM)", obs.OBS_TEXT_DEFAULT)
        obs.obs_properties_add_text(day_group, day:lower() .. "_category",    "Category",                          obs.OBS_TEXT_DEFAULT)

        obs.obs_properties_add_group(props, day:lower() .. "_group", "🗓️ " .. day, obs.OBS_GROUP_NORMAL, day_group)
    end

    return props
end

----------------------------------------------------------------
-- 8) SCRIPT UPDATE
--    We no longer allow UI to change update interval (fixed at 60s).
----------------------------------------------------------------
function script_update(new_settings)
    -- OBS text source settings
    settings.text_source_name       = obs.obs_data_get_string(new_settings, "text_source_name") or ""

    settings.prefix                 = obs.obs_data_get_string(new_settings, "prefix")    or "Next Stream"
    settings.separator              = obs.obs_data_get_string(new_settings, "separator") or " | "
    settings.suffix                 = obs.obs_data_get_string(new_settings, "suffix")    or ""
    settings.day_format             = obs.obs_data_get_string(new_settings, "day_format")       or "full"
    settings.time_format            = obs.obs_data_get_string(new_settings, "time_format")      or "24h"
    settings.max_streams_displayed  = obs.obs_data_get_int(new_settings,    "max_streams_displayed")

    settings.category_display_mode  = obs.obs_data_get_string(new_settings, "category_display_mode") or "show"

    settings.even_week_time         = obs.obs_data_get_string(new_settings, "even_week_time") or "20:00"
    settings.odd_week_time          = obs.obs_data_get_string(new_settings, "odd_week_time")  or "21:00"

    -- File output settings
    settings.file_path                = obs.obs_data_get_string(new_settings, "file_path") or ""
    settings.file_use_emojis          = obs.obs_data_get_bool(new_settings,  "file_use_emojis")
    settings.file_show_category       = obs.obs_data_get_bool(new_settings,  "file_show_category")
    settings.file_max_streams_displayed = obs.obs_data_get_int(new_settings, "file_max_streams_displayed")
    settings.file_separator           = obs.obs_data_get_string(new_settings, "file_separator") or " | "
    settings.file_multiline           = obs.obs_data_get_bool(new_settings, "file_multiline")

    -- Weekday-specific
    local day_keys = {"monday","tuesday","wednesday","thursday","friday","saturday","sunday"}
    for i, d in ipairs(day_keys) do
        settings.days[i].enabled     = obs.obs_data_get_bool(new_settings,  d .. "_enabled")
        settings.days[i].auto_time   = (obs.obs_data_get_string(new_settings, d .. "_time_choice") == "auto")
        settings.days[i].custom_time = obs.obs_data_get_string(new_settings, d .. "_custom_time") or ""
        settings.days[i].category    = obs.obs_data_get_string(new_settings, d .. "_category")    or ""
    end

    update_text_source()
end

----------------------------------------------------------------
-- 9) SCRIPT DESCRIPTION & LIFECYCLE
----------------------------------------------------------------
function script_description()
    return "K_STYER’s Dynamic Next Stream [2.0] is your ultimate scheduling solution for OBS. It automatically displays upcoming streams with a 60-second refresh, interprets AM/PM inputs, and supports both 24h and 12h formats. Customize day and category settings per even/odd week. Additionally, generate a .txt record—single- or multiline—complete with optional emojis. Configuration is entirely menu-driven for maximum convenience."
end

function script_load(new_settings)
    script_update(new_settings)
    -- Fixed 60s interval
    obs.timer_add(update_text_source, 60000)
end

function script_unload()
    obs.timer_remove(update_text_source)
end