/*
 * timesel.c - Time selector
 * Copyright (C) 2024  Alexander Rosenberg
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version. See the LICENSE file for more information.
 */
#include "timesel.h"

#include <err.h>

void time_sel_init(TimeSelection *ts, DateSelection *ds, bool do_second) {
    ts->ds = ds;
    ts->do_second = do_second;
    time_sel_reset(ts);
}

static void time_sel_clamp(TimeSelection *ts) {
    if (ts->ds) {
        if (ts->ds->end_time.local_year == ts->ds->year &&
            ts->ds->end_time.local_month == ts->ds->month &&
            ts->ds->end_time.local_day == ts->ds->day) {
            if (ts->hour > ts->ds->end_time.local_hour) {
                ts->hour = ts->ds->end_time.local_hour;
            }
            if (ts->hour == ts->ds->end_time.local_hour &&
                ts->minute > ts->ds->end_time.local_minute) {
                ts->minute = ts->ds->end_time.local_minute;
            }

            if (ts->hour == ts->ds->end_time.local_hour &&
                ts->minute == ts->ds->end_time.local_minute &&
                ts->second > ts->ds->end_time.local_second) {
                ts->second = ts->ds->end_time.local_second;
            }
        } else if (ts->ds->start_time.local_year == ts->ds->year &&
                   ts->ds->start_time.local_month == ts->ds->month &&
                   ts->ds->start_time.local_day == ts->ds->day) {
            if (ts->hour < ts->ds->start_time.local_hour) {
                ts->hour = ts->ds->start_time.local_hour;
            }
            if (ts->hour == ts->ds->start_time.local_hour &&
                ts->minute < ts->ds->start_time.local_minute) {
                ts->minute = ts->ds->start_time.local_minute;
            }
            if (ts->hour == ts->ds->start_time.local_hour &&
                ts->minute == ts->ds->start_time.local_minute &&
                ts->second > ts->ds->start_time.local_second) {
                ts->second = ts->ds->start_time.local_second;
            }
        }
    } 
}

static void time_sel_add(TimeSelection *ts, int amount) {
    switch (ts->stage) {
    case TS_STAGE_HOUR:
        ts->hour += amount;
        break;
    case TS_STAGE_MINUTE:
        ts->minute += amount;
        break;
    case TS_STAGE_SECOND:
        ts->second += amount;
        break;
    }
    if (ts->second >= 60) {
        ++ts->minute;
    } else if (ts->second < 0) {
        --ts->minute;
    }
    if (ts->minute >= 60) {
        ++ts->hour;
    } else if (ts->minute  < 0) {
        --ts->hour;
    }
    ts->hour %= 24;
    ts->minute %= 60;
    ts->second %= 60;
    if (ts->hour < 0) {
        ts->hour += 24;
    }
    if (ts->minute < 0) {
        ts->minute += 60;
    }
    if (ts->second < 0) {
        ts->second += 60;
    }
    time_sel_clamp(ts);
}

TimeSelState time_sel_dispatch(TimeSelection *ts, SensorState *state,
                               const char *label) {
    if (state->back_down) {
        if (ts->stage != TS_STAGE_HOUR) {
            --ts->stage;
        } else {
            lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
                                LCD_DISPLAY_ON);
            return TIME_SEL_BACK;
        }
    }
    if (state->sel_down) {
        if ((ts->do_second && ts->stage == TS_STAGE_SECOND) ||
            (!ts->do_second && ts->stage == TS_STAGE_MINUTE)) {
            lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
                                LCD_DISPLAY_ON);
            return TIME_SEL_DONE;
        } else {
            ++ts->stage;
        }
    }
    if (ts->ds) {
        UtilDate start, end;
        if (!get_database_limits(state->db, PERIOD_DAY, &start, &end)) {
            warnx("failed to query database limits");
            lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
                                LCD_DISPLAY_ON);
            return TIME_SEL_ERROR;
        }
        ts->ds->start_time = start;
        ts->ds->end_time = end;
    }
    time_sel_add(ts, state->up_down - state->down_down);
    lcd_clear(state->lcd);
    lcd_move_to(state->lcd, 0, 0);
    lcd_write_string(state->lcd, label);
    char time_line[17];
    int cursor_pos;
    if (ts->do_second) {
        const char *format;
        switch (ts->stage) {
        case TS_STAGE_HOUR:
            format = ">%02d:%02d:%02d";
            cursor_pos = 0;
            break;
        case TS_STAGE_MINUTE:  
            format = "%02d:>%02d:%02d";
            cursor_pos = 3;
            break;
        case TS_STAGE_SECOND:
            format = "%02d:%02d:>%02d";
            cursor_pos = 6;
            break;
        }
        snprintf(time_line, 17, format, ts->hour, ts->minute, ts->second);
    } else {
        const char *format;
        switch (ts->stage) {
        case TS_STAGE_HOUR:
            format = ">%02d:%02d";
            cursor_pos = 0;
            break;
        default:  // minute or second (which shouldn't happen)
            format = "%02d:>%02d";
            cursor_pos = 3;
            break;
        }
        snprintf(time_line, 17, format, ts->hour, ts->minute);
    }
    lcd_move_to(state->lcd, 1, 0);
    lcd_write_string(state->lcd, time_line);
    lcd_move_to(state->lcd, 1, cursor_pos);
    lcd_display_control(state->lcd, LCD_CURSOR_BLINK, LCD_CURSOR_ON,
                        LCD_DISPLAY_ON);
    return TIME_SEL_CONTINUE;
}

void time_sel_reset(TimeSelection *ts) {
    ts->hour = 0;
    ts->minute = 0;
    ts->stage = TS_STAGE_HOUR;
}

int64_t timedate_sel_to_uts_timestamp(DateSelection *ds, TimeSelection *ts) {
    struct tm broken_time = {
        .tm_sec = ts->second,
        .tm_min = ts->minute,
        .tm_hour = ts->hour,
        .tm_mday = ds->day,
        .tm_mon = ds->month - 1,
        .tm_year = ds->year - 1900,
        .tm_isdst = -1,
    };
    time_t it = mktime(&broken_time);
    if (it < 0) {
        warnx("failed to convert to UTC timestamp");
        return 0;
    }
    return it;
}