import datetime
import json
import logging
import math
import time

from flask import (Flask, request, jsonify, abort, render_template_string, render_template)
from markupsafe import Markup

from ltsdb_json import LTS

log = logging.getLogger(__name__)

class Dashboard:
    def __init__(self, filename="dashboard.json"):
        with open (filename) as fh:
            d = json.load(fh)
        self.title = d["title"]
        log.debug("title = “%s”", self.title)
        self.description = d["description"]
        self.widgets = []
        for w in d["widgets"]:
            if w["type"] == "timeseries":
                # XXX - currently just a copy of the gauge code,
                # but I want to add support for timeseries graphs with 
                # multiple series later so this will change
                if w.get("multi"):
                    ts_list = LTS.find(w["data"][0])
                    for ts in ts_list:
                        tso = LTS(id=ts)
                        if not tso.data:
                            log.warning("%s has no data: Skipping", tso.id)
                            continue
                        if tso.data[-1][0] < time.time() - 7 * 86400:
                            log.info("%s too old; Skipping", tso.id)
                            continue
                        w1 = {**w, "data": [ts]}
                        self.widgets.append(TimeSeries(w1))
                else:
                    self.widgets.append(TimeSeries(w))
            elif  w["type"] == "gauge":
                if w.get("multi"):
                    ts_list = LTS.find(w["data"][0])
                    for ts in ts_list:
                        tso = LTS(id=ts)
                        if not tso.data:
                            log.warning("%s has no data: Skipping", tso.id)
                            continue
                        if tso.data[-1][0] < time.time() - 86400:
                            log.info("%s too old; Skipping", tso.id)
                            continue
                        w1 = {**w, "data": [ts]}
                        self.widgets.append(Gauge(w1))
                else:
                    self.widgets.append(Gauge(w))
            else:
                self.widgets.append(Widget(w))

        # Sort widgets by ascending healthscore to get the most critical at the
        # top.
        self.widgets.sort(key=lambda w: w.healthscore())

    def as_html(self):
        return render_template("dashboard.html", dashboard=self)



class Widget:
    def __init__(self, d):
        log.debug("")
        self.type = d["type"]
        self.stops = d["stops"]
        self.yscale = d.get("yscale", "linear")
        self.extra = {}
        log.debug("data = %s", d["data"])
        self.lts = LTS(id=d["data"][0]) # by default we handle only one data source
        self.lastvalue = self.lts.data[-1][1]

    def as_html(self):
        log.debug("")
        return Markup(render_template("widget.html", widget=self))

    def healthscore(self, value=None):
        """
        Return a score between 0 (unhealthy) and 100 (healthy)
        """
        if value == None:
            value = self.lastvalue
        log.debug("stops = %s", self.stops)
        stops = self.stops
        if stops[-1] < stops[0]:
            value = -value
            stops = [-v for v in stops]

        if value <= stops[0]:
            log.debug("ok")
            return 100
        if value >= stops[-1]:
            log.debug("fail")
            return 0
        for i in range(0, len(stops) - 1):
            if stops[i] <= value < stops[i+1]:
                log.debug("at stop %d", i)
                return 100 - ((value - stops[i]) / (stops[i+1] - stops[i]) + i) * 100 / (len(stops) - 1)

    def criticalcolor(self, value=None):
        healthscore = self.healthscore(value)
        hue = round(healthscore * 120 / 100)
        brightness = 30
        return f"hsl({hue}, 100%, {brightness}%)"

    @property
    def description_formatted(self):
        s = "<table class='description'>"
        for d, v in self.lts.description.items():
            if v:
                s += render_template_string(
                        "<tr><th>{{d}}:</th><td>{{v}}</td></tr>",
                        d=d, v=v)
        for d, v in self.extra.items():
            if v:
                s += render_template_string(
                        "<tr class='extra'><th>{{d}}:</th><td>{{v}}</td></tr>",
                        d=d, v=v)
        s += "</table>"
        return Markup(s)

class TimeSeries(Widget):
    def __init__(self, d):
        log.debug("")
        super().__init__(d)
        pass

    @property
    def graph(self):
        def t2x(t):
            x = n - math.log((t_last - t) / (n*dt) + 1) * n / k
            return x

        def v2y(v):
            if self.yscale == "log":
                return (1 -   math.log(v / min_value)
                            / math.log(max_value / min_value)
                       ) * 200
            elif self.yscale == "linear":
                return (1 - v/max_value) * 200
            else:
                raise ValueError(f"Unknown yscale {self.yscale}")

        def set_x_tickmarks():
            log.debug("")
            tickmarks = []
            t = v_data[-1]["t"]
            x = v_data[-1]["x"]
            d = datetime.datetime.fromtimestamp(t)
            tickmarks.append({"t": t, "t_h": d.strftime("%Y-%m-%d %H:%M:%S"), "x": x})

            min_step = 25
            steps = ("s", "m", "h", "D", "10D", "M", "Y")
            step_i = 0
            while step_i < len(steps):
                t0 = tickmarks[-1]["t"]
                x0 = tickmarks[-1]["x"]
                d0 = datetime.datetime.fromtimestamp(t0)

                log.debug("step_i = %s", step_i)
                if steps[step_i] == "s":
                    d1 = datetime.datetime(d0.year, d0.month, d0.day, d0.hour, d0.minute, d0.second)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        d1 -= datetime.timedelta(seconds=1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "m":
                    d1 = datetime.datetime(d0.year, d0.month, d0.day, d0.hour, d0.minute)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        d1 -= datetime.timedelta(minutes=1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "h":
                    d1 = datetime.datetime(d0.year, d0.month, d0.day, d0.hour)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        d1 -= datetime.timedelta(hours=1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "D":
                    d1 = datetime.datetime(d0.year, d0.month, d0.day)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        d1 -= datetime.timedelta(days=1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "10D":
                    year = d0.year
                    month = d0.month
                    day = d0.day
                    if day > 21:
                        day = 21
                    elif day > 11:
                        day = 11
                    elif day > 1:
                        day = 1
                    else:
                        day = 21
                        month -= 1
                        if month < 1:
                            month += 12
                            year -= 1
                    d1 = datetime.datetime(year, month, day)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        if day > 21:
                            day = 21
                        elif day > 11:
                            day = 11
                        elif day > 1:
                            day = 1
                        else:
                            day = 21
                            month -= 1
                            if month < 1:
                                month += 12
                                year -= 1
                        d1 = datetime.datetime(year, month, day)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "M":
                    d1 = datetime.datetime(d0.year, d0.month, 1)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        if d1.month > 1:
                            d1 = datetime.datetime(d1.year, d1.month-1, 1)
                        else:
                            d1 = datetime.datetime(d1.year-1, 12, 1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            step_i += 1
                            continue

                if steps[step_i] == "Y":
                    d1 = datetime.datetime(d0.year, 1, 1)
                    t1 = d1.timestamp()
                    x1 = t2x(t1)
                    if x0 - x1 < min_step:
                        d1 = datetime.datetime(d1.year-1, 1, 1)
                        t1 = d1.timestamp()
                        x1 = t2x(t1)
                        if x0 - x1 < min_step:
                            log.debug("t0 = %s, x0 = %s, t1 = %s, x1 = %s", t0, x0, t1, x1)
                            step_i += 1
                            continue
                if x1 < 0:
                    break
                tickmarks.append({"t": t1, "t_h": d1.strftime("%Y-%m-%d %H:%M:%S"), "x": x1})
            if tickmarks[-1]["x"] > min_step:
                t = v_data[0]["t"]
                x = v_data[0]["x"]
                d = datetime.datetime.fromtimestamp(t)
                tickmarks.append({"t": t, "t_h": d.strftime("%Y-%m-%d %H:%M:%S"), "x": x})
            self.x_tickmarks = tickmarks
            log.debug("")

        def set_y_tickmarks():
            log.debug("")
            unit = self.lts.description["unit"]
            self.y_tickmarks = []
            if self.yscale == "linear":
                log.debug("")
                if unit == "s" and max_value > 3600:
                    if max_value >= 16 * 7 * 86400:
                        step = 4 * 7 * 86400
                        step_d = 4
                        unit = "w"
                    elif max_value >= 4 * 7 * 86400:
                        step = 7 * 86400
                        step_d = 1
                        unit = "w"
                    elif max_value >= 10 * 86400:
                        step = 3 * 86400
                        step_d = 3
                        unit = "d"
                    elif max_value >= 4 * 86400:
                        step = 86400
                        step_d = 1
                        unit = "d"
                    elif max_value >= 4 * 3600:
                        step = 3600
                        step_d = 1
                        unit = "h"
                    else:
                        step = 10 * 60
                        step_d = 10
                        unit = "m"
                    v = 0
                    v_d = 0
                    while v < max_value:
                        y = v2y(v)
                        log.debug("v = %s, y = %s", v, y)
                        self.y_tickmarks.append({"y": y, "v_h": f"{v_d} {unit}"})
                        v += step
                        v_d += step_d

                else:
                    step = 10 ** math.floor(math.log10(max_value))
                    v = 0
                    while v < max_value:
                        y = v2y(v)
                        log.debug("v = %s, y = %s", v, y)
                        self.y_tickmarks.append({"y": y, "v_h": str(v)})
                        v += step
                    log.debug("")
            elif self.yscale == "log":
                if unit == "s" and max_value > 3600:
                    steps = (
                        (3600, "1 h"),
                        (86400, "1 d"),
                        (7*86400, "1 w"),
                        (28*86400, "4 w"),
                        (365*86400, "1 y"),
                        (3652.5 * 86400, "10 y"),
                    )
                    for s in steps:
                        if min_value <= s[0] <= max_value:
                            self.y_tickmarks.append({"y": v2y(s[0]), "v_h": s[1]})

                else:
                    log.debug("")
                    v = 10 ** math.ceil(math.log10(min_value))
                    log.debug("v = %s", v)
                    if v > max_value:
                        # Implement that when it happens
                        log.warning("No tickmark between %s and %s", min_value, max_value)
                        return
                    while v <= max_value:
                        y = v2y(v)
                        log.debug("v = %s, y = %s", v, y)
                        self.y_tickmarks.append({"y": y, "v_h": str(v)})
                        v *= 10
                    log.debug("")
            else:
                log.debug("")
                raise ValueError(f"Unknown yscale {self.yscale}")
            log.debug("")


        log.debug("in graph for %s", self.lts.id)
        data = self.lts.data
        n = len(data)
        t_last = data[-1][0]
        if len(data) < 5:
            return "(not enough data)"
        dt = (t_last - data[-5][0]) / 4
        k = math.log((t_last - data[0][0]) / dt / n + 1)
        log.debug("times = [%s ... %s ... %s]", data[0][0], data[-5][0], data[-1][0])

        max_value = max([d[3] if len(d) >= 4 else d[1] for d in self.lts.data])
        max_value = max(max_value, 0.001) # ensure positive
        if self.yscale == "log":
            try:
                min_value = min(d[1] for d in self.lts.data if d[1] > 0)
                self.extra["min"] = "%g" % min_value
            except ValueError:
                # no non-negative values
                min_value = max_value / 2
            if any(True for d in self.lts.data if d[1] < min_value):
                # if there are values smaller than the minimum (i.e.
                # 0 or negative unless we have a configured minimum)
                # reduce the minimum again so that we have a distinct 
                # value to clamp to.
                min_value /= 2
            if min_value == max_value:
                # Make sure min_value is less than max_value
                min_value /= 2
            log.debug("min_value = %s, max_value = %s", min_value, max_value)
        self.extra["max"] = "%g" % max_value
        self.extra["last"] = "%g" % data[-1][1]
        log.debug("collecting data")
        v_data = []
        for i in range(n):
            t = data[i][0]
            v = data[i][1]
            if len(data[i]) >= 4:
                v_min = data[i][2]
                v_max = data[i][3]
            else:
                v_min = data[i][1]
                v_max = data[i][1]
            x = t2x(t)
            t_h = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(t))
            y = v2y(v)
            y_min = v2y(v_min)
            y_max = v2y(v_max)
            #print(t, t_h, x)
            v_data.append(
                    {
                        "t": t,
                        "v": v,
                        "x": x,
                        "y": y,
                        "y_min": y_min,
                        "y_max": y_max,
                        "color": self.criticalcolor(v),
                    })

        log.debug("setting tickmarks")
        set_x_tickmarks()
        set_y_tickmarks()

        log.debug("assembling svg")
        html = ""
        html += "<svg width=1150 height=300>"
        for tm in self.x_tickmarks:
            html += f"<line x1={tm['x']} y1=0 x2={tm['x']} y2=200 stroke='#CCC' />"
            html += f"<text transform='translate({tm['x']}, 210) rotate(30)' fill='#888'>{tm['t_h']}</text>"
        for tm in self.y_tickmarks:
            log.debug("tm = %s", tm)
            html += f"<line x1=0 y1={tm['y']} x2=1000 y2={tm['y']} stroke='#CCC' />"
            html += f"<text x=1005 y={tm['y']} fill='#888'>{tm['v_h']}</text>"
        for v in v_data:
            html += f"<line x1={v['x']-3} x2={v['x']+3} y1={v['y']} y2={v['y']} stroke='{v['color']}' />"
            html += f"<line x1={v['x']} x2={v['x']} y1={v['y_min']} y2={v['y_max']} stroke='{v['color']}' />"
        html += "</svg>"
        log.debug("len(html) = %s", len(html))
        return Markup(html)

    def as_html(self):
        log.debug("in as_html")
        return Markup(render_template("timeseries.html", widget=self))

class Gauge(Widget):
    def __init__(self, d):
        super().__init__(d)
        pass

    gaugesize = 100

    @property
    def gaugepos(self):
        max_value = max([d[1] for d in self.lts.data])
        max_value = max(max_value, 1) # ensure positive
        log.debug("max_value = %s", max_value)
        return self.lastvalue / max_value * self.gaugesize

    def as_html(self):
        log.debug("")
        self.lastvalue = self.lts.data[-1][1]
        value = self.lastvalue
        unit = self.lts.description["unit"]
        log.debug("unit = %s", unit)
        if unit == "s":
            if value >= 365.25 * 86400:
                value /= 365.25 * 86400
                unit = "years"
            elif value >= 86400:
                value /= 86400
                unit = "days"
            elif value >= 3600:
                value /= 3600
                unit = "h"
            elif value >= 60:
                value /= 60
                unit = "m"
            elif value >= 1:
                pass
            elif value >= 0.001:
                value *= 1000
                unit = "ms"
        self.lastvalue_formatted = Markup(f"<span class='value'>{value:.2f}</span><span class='unit'>{unit}</unit>")
        return Markup(render_template("gauge.html", widget=self))