import datetime
from urllib import parse
from django.contrib.gis.db import models
from django.contrib.auth.models import User
from django_extensions.db.fields import AutoSlugField
from django_countries.fields import CountryField
from django.utils.translation import ugettext as _
from django.template.defaultfilters import slugify
from . import validators


class CaseStudy(models.Model):
    """Model for case studies submitted to the Ojuso Platform"""

    # Choice lists for drop-downs
    SECTOR_CHOICES = (
        (_('Renewable Energy Generation'), (
            ('WND', _('Wind')),
            ('SOL', _('Solar')),
            ('HYD', _('Hydro')),
        )),
        ('PG', _('Power Grids')),
        ('SM', _('Supply of Minerals')),
    )

    POSITIVE_NEGATIVE_CHOICES = (
        ('P', _('Positive')),
        ('N', _('Negative'))
    )

    LAND_OWNERSHIP_CHOICES = (
        ('PRI', _('Private Land')),
        ('PUB', _('Public Land')),
        ('COM', _('Community Land')),
        ('OTH', _('Other')),
    )

    LOCATION_CONTEXT_CHOICES = (
        ('RUR', _('Rural')),
        ('URB', _('Urban')),
    )

    TYPE_OF_ECOSYSTEM_CHOICES = (
        (_('Water Based'), (
            ('MARINE', _('Marine (e.g. Ocean, Sea)')),
            ('FRESH', _('Freshwater (e.g. Freshwater, Lake)')),
        )),
        (_('Land Based'), (
            ('FOREST', _('Forest/Jungle')),
            ('AGRI', _('Agricultural Land')),
            ('GRASS', _('Grassland')),
            ('DESERT', _('Desert (Tundra, Ice or Sand)')),
            ('WETLND', _('Wetland (Marsh, Mangrove, Peat Soil)')),
            ('URBAN', _('Urban')),
        ))
    )

    PROJECT_STATUS_CHOICES = (
        ('EXSTNG', _('Existing Project')),
        ('UCONST', _('Under Construction')),
        ('PROJCD', _('Projected Project')),
    )

    GENERATION_TECHNOLOGY_CHOICES = (
        (_('Wind energy'), (
            ('SSWE', _('Small-scale (less than 500kW)')),
            ('LSWE', _('Large-scale (more than 500kW)'))
        )),
        (_('Photovoltaic electricity'), (
            ('SSPV', _('Small-scale (less than 500kW)')),
            ('LSPV', _('Large-scale (more than 500kW)'))
        )),
        (_('Hydroelectric'), (
            ('SHYD', _('Small-scale (less than 1MW)')),
            ('MHYD', _('Medium-scale (between 1-20MW)')),
            ('LHYD', _('Large-scale (more than 20MW - often not considered renewable)')),
        )),
        ('STHE', _('Solar thermal electricity (e.g using parabolic reflectors)')),
        ('GEOT', _('Geothermal electricity')),
        ('BIOG', _('Biogas turbine')),
        ('OTHB', _('Other biomass (including liquid/solid biofuel)')),
        ('OTHR', _('Other (tidal, wave etc)'))
    )

    POWER_TECHNOLOGY_CHOICES = (
        ('PT', _('Power transmission (grid lines, substations etc)')),
        ('ES', _('Energy storage (pumped storage, compressed air, battery systems etc')),
        ('OT', _('Others'))
    )

    # Dynamically generate a list of choices 40 years prior and after the current year.
    YEAR_CHOICES = [(r, r) for r in
                    range((datetime.datetime.now().year - 40),
                          (datetime.datetime.now().year + 41))]

    ##
    # Meta Fields
    ##

    # User who submitted case study
    author = models.ForeignKey(
            User,
            models.SET_NULL,
            blank=True,
            null=True,
            editable=False
    )

    # Date and time of submission
    date_created = models.DateTimeField(auto_now_add=True, null=False)

    # Slug derived from entry_name, used in urls for SEO
    # TODO: Change this so it's not dynamic. Slugs should never change.
    slug = AutoSlugField(populate_from=['entry_name'])

    ##
    # First Screen
    ##

    # 1.1
    entry_name = models.CharField(
        verbose_name=_("Entry Name"),
        help_text=_("Enter the name of the entry. This should usually be the\
                   name of project."),
        max_length=128
    )

    # N/A - Not explicitly listed in spec
    location = models.PointField(
        verbose_name=_("Project location"),
        help_text=_("Place a marker using the tools on the left of the map. Zoom in as far as you can so the placement \
                    is accurate (important)")
    )

    # 1.2
    sector_of_economy = models.CharField(
        verbose_name=_("Sector of economy"),
        help_text=_("Which sector of the renewable energy economy is most\
                    relevant?"),
        max_length=3,
        choices=SECTOR_CHOICES
    )

    # 1.3
    positive_or_negative = models.CharField(
        verbose_name=_("Positive or negative?"),
        help_text=_("Is the case study a positive case or a negative case?"),
        max_length=1,
        choices=POSITIVE_NEGATIVE_CHOICES
    )

    # 1.4
    country = CountryField(
        verbose_name=_("Country field"),
        help_text=_("Select the country of the project")
    )

    # 1.5.1
    area_of_land = models.IntegerField(
        verbose_name=_("Approximate land area"),
        help_text=_("The area of land covered by the project (in km²)")
    )

    # 1.5.2
    land_ownership = models.CharField(
        verbose_name=_("Land ownership"),
        help_text=_("What type of ownership does the land fall under?"),
        max_length=3,
        choices=LAND_OWNERSHIP_CHOICES
    )

    # 1.5.3
    land_ownership_details = models.CharField(
        verbose_name=_("Land ownership details"),
        help_text=_("Please specify details about land ownership if you chose 'other'"),
        max_length=256,
        null=True,
        blank=True,
    )

    # 1.5.4
    location_context = models.CharField(
        verbose_name=_("Location"),
        help_text=_("Select the context that is most applicable to this case\
                    study."),
        max_length=3,
        choices=LOCATION_CONTEXT_CHOICES
    )

    # 1.5.5
    type_of_ecosystem = models.CharField(
        verbose_name=_("Type of ecosystem"),
        help_text=_("Select the most relevant type of ecosystem."),
        max_length=6,
        choices=TYPE_OF_ECOSYSTEM_CHOICES,
    )

    # 1.5.5.3
    describe_ecosystem = models.CharField(
        verbose_name=_("Describe the ecosystem"),
        help_text=_("In your own words, add more detail about the ecosystem."),
        max_length=256,
    )

    # 1.5.6
    affects_indigenous = models.BooleanField(
        verbose_name=_("Affects indigenous people?"),
        help_text=_("Does the project affect indigenous communities?")
    )

    # 1.5.6.1
    affects_indigenous_detail = models.CharField(
        verbose_name=_("Affects Indigenous - Details"),
        help_text=_("What group of indigenous people does the community belong\
                    to?"),
        max_length=256,
        default=None,
        null=True,
        blank=True
    )

    # 1.6
    project_status = models.CharField(
        verbose_name=_("Status of Project"),
        help_text=_("What is the status of the current project?"),
        max_length=6,
        choices=PROJECT_STATUS_CHOICES
    )

    # 1.7
    start_year = models.IntegerField(
        verbose_name=_("Start year"),
        help_text=_("Select the year the project was started. \
                    If the project hasn't begun, select the projected start year."),
        choices=YEAR_CHOICES,
        default=None,
        null=True,
        blank=True
    )

    # 1.8
    completion_year = models.IntegerField(
        verbose_name=_("Completion year"),
        help_text=_("Select the year the project was completed. \
                    If the project hasn't finished, select the projected completion year."),
        choices=YEAR_CHOICES,
        default=None,
        null=True,
        blank=True
    )

    # 1.9
    synopsis = models.TextField(
        verbose_name=_("Synopsis"),
        help_text=_("Briefly describe the project. This will be displayed at\
                    the top of the case study page. Maximum 500 chars (about \
                    3½ tweets)"),
        max_length=500
    )

    # 1.10
    full_description = models.TextField(
        verbose_name=_("Full Description"),
        help_text=_("Describe the project in full. Separate paragraphs with a\
                    new line Please add as much detail as you feel is necessary\
                    here.")
    )

    # 1.11
    project_owners = models.CharField(
        verbose_name=_("Project and facility owners"),
        help_text=_("List companies or organisations that own the project and/or facilities. Separate with a comma."),
        max_length=120,
        default=None,
        null=True,
        blank=True
    )

    # 1.12
    shareholders = models.CharField(
        verbose_name=_("Shareholders of the project owners"),
        help_text=_("List shareholders of the project owners you've just listed. Separate with a comma."),
        max_length=120,
        default=None,
        null=True,
        blank=True
    )

    # 1.13
    financial_institutions = models.CharField(
        verbose_name=_("Financial institutions"),
        help_text=_("List banks and other financial institutions that have or are considering extending loans \
                     or guarantees to the project. Separate with a comma."),
        max_length=120,
        default=None,
        null=True,
        blank=True
    )

    # 1.14
    energy_customers = models.CharField(
        verbose_name=_("Energy consumers"),
        help_text=_("List any wholesale energy customers that take energy from the development. E.g. 'national \
                    grids' or private energy suppliers."),
        max_length=120,
        default=None,
        null=True,
        blank=True
    )

    # 1.15.1
    image = models.ImageField(
        verbose_name=_("Image")
    )

    # 1.15.2
    image_caption = models.CharField(
        verbose_name=_("Image caption"),
        max_length=500,
        default=None,
        null=True,
    )

    # 1.15.3
    image_credit = models.CharField(
        verbose_name=_("Image credit(s)"),
        max_length=200,
        default=None,
        null=True,
    )

    # 1.16.1
    video = models.URLField(
        verbose_name=_("YouTube Video"),
        help_text=_("Copy the URL to a related YouTube™ video that relates to the case study."),
        max_length=43,
        validators=[validators.YoutubeURLValidator()]
    )

    # 1.16.2
    video_caption = models.CharField(
        verbose_name=_("Video caption"),
        max_length=500,
        default=None,
        null=True,
    )

    # 1.16.3
    video_credit = models.CharField(
        verbose_name=_("Video credit(s)"),
        max_length=500,
        default=None,
        null=True,
    )
    # 1.17.1
    media_coverage_mainstream = models.TextField(
        verbose_name=_("Links to media reports"),
        help_text=_("Provide any links to mainstream media coverage."),
        max_length=500,
        default=None,
        null=True,
    )

    # 1.17.2
    media_coverage_independent = models.TextField(
        verbose_name=_("Independent grassroots reports"),
        help_text=_("Provide any links to grassroots/independent media coverage."),
        max_length=500,
        default=None,
        null=True,
    )

    # 1.18.1
    community_voices = models.TextField(
        verbose_name=_("Community Voices"),
        help_text=_("Add any direct quotes from members of the community that \
                  relate to this project")
    )

    # 1.18.2
    direct_comms = models.TextField(
        verbose_name=_("Reports of direct communications"),
        help_text=_("Add any reports of direct communication between community members and \
                    representatives of developers/companies/investors."),
        max_length=500,
        default=None,
        null=True,
    )

    # 1.18.3
    social_media_links = models.TextField(
        verbose_name=_("Social media links"),
        help_text=_("Add any links to social media accounts directly relating to the project."),
        max_length=500,
        default=None,
        null=True,
        blank=True
    )

    ##
    # Second Screen
    ##

    # 2.1.1
    generation_technology = models.CharField(
        verbose_name=_("Generation technology"),
        help_text=_("Select the type of renewable energy generation that most applies to this case study."),
        max_length=4,
        choices=GENERATION_TECHNOLOGY_CHOICES,
        default=None,
        null=True,
        blank=True
    )

    # 2.1.1.12
    # Should be filled in if 2.1.1 was answered as biogas or biomass.
    biomass_detail = models.CharField(
        verbose_name=_("Generation technology detail"),
        help_text=_("If you selected biogas or biomass, please describe the feedstock (where the fuel came from e.g. \
                   corn, algae, anaerobic digestion, commercial waste etc)"),
        max_length=200,
        default=None,
        null=True,
        blank=True
    )

    # 2.1.1.14
    generation_technology_other = models.CharField(
        verbose_name=_("Other generation type"),
        help_text=_("If you selected other, please specify the generation technology (e.g. tidal, wave etc)"),
        max_length=200,
        default=None,
        null=True,
        blank=True
    )

    # 2.1.2
    total_generation_capacity = models.PositiveIntegerField(
        verbose_name=_("Total generation capacity (in kW)"),
        help_text=_("Please enter the total generation capacity of the project in kW"),
        default=None,
        null=True,
        blank=True,
    )

    # 2.1.3 - autocomplete_light queryset

    # 2.1.4
    total_investment = models.IntegerField(
        verbose_name=_("Total investment (in USD)"),
        help_text=_("The approximate total investment for the project in USD."),
        default=None,
        null=True,
        blank=True
    )

    # 2.1.5
    technical_or_economic_details = models.CharField(
        verbose_name=_("Additional technical or economic details"),
        help_text=_("Specify any additional technical or economic details relating to the project."),
        max_length=500,
        default=None,
        null=True,
        blank=True
    )

    # 2.2 - Only if 1.2.2 selected
    # 2.2.1
    power_technology = models.CharField(
        verbose_name=_("Power technology"),
        help_text=_("Select the related energy technology."),
        max_length=2,
        choices=POWER_TECHNOLOGY_CHOICES,
        default=None,
        null=True,
        blank=True
    )

    power_technology_other = models.CharField(
        verbose_name=_("Other power technology"),
        help_text=_("If you answered 'others', please specify the power technologies."),
        max_length=128,
        default=None,
        null=True,
        blank=True
    )

    energy_storage_capacity = models.IntegerField(
        verbose_name=_("Energy storage capacity"),
        help_text=_("Enter the total capacity of the energy storage system."),
        default=None,
        null=True,
        blank=True
    )

    ##
    # Third Screen
    ##

    ##
    # Fourth Screen
    ##

    # 4.1
    official_project_documents = models.FileField(
        verbose_name=_("Official project documents"),
        help_text=_("Attach any legal or official documents that relate to the project."),
        default=None,
        null=True,
        blank=True
    )

    # 4.2
    other_documents = models.FileField(
        verbose_name=_("Other documents"),
        help_text=_("Attach any other documents that relate to the project."),
        default=None,
        null=True,
        blank=True
    )

    # 4.3
    definition_of_affected_territories = models.CharField(
        verbose_name=_("Definition of affected territories"),
        help_text=_("In your own words, define the territories that the project will affect."),
        max_length=512,
        default=None,
        null=True,
        blank=True
    )

    # 4.4
    shown_on_other_platforms = models.NullBooleanField(
        verbose_name=_("Show on other platforms?"),
        help_text=_("Tick the box if you would like us to show this case study on other social media platforms"),
        default=None,
        null=True,
        blank=True
    )

    # 4.4.1
    shown_on_other_platforms_detail = models.CharField(
        verbose_name=_("Show on other platforms - Detail"),
        help_text=_("List the social media platforms that you would like us to specifically publish the case study on"),
        max_length=128,
        null=True,
        blank=True
    )

    def __str__(self):
        """The String representation of the case study. (Entry name with country name.)"""
        return "%s in %s" % (self.entry_name, self.country.name)

    def clean(self, *args, **kwargs):
        """Perform validation on the model as a whole and throw a ValidationError if anything isn't how it should be."""
        pass

    def save(self, *args, **kwargs):
        """Override the save method to create a slug when the model is created. Slug is only created and never modified
        as we are basing our URLs on it and don't want it to change - ever."""
        if not self.pk:
            # Newly created object, so set slug
            self.slug = slugify(self.entry_name)
        # Continue normal save method by calling original save method.
        super(CaseStudy, self).save(*args, **kwargs)

    def get_video_id(self):
        """Gets the 11 character YouTube video ID from the video field."""
        return parse.parse_qs(parse.urlparse(self.video).query)["v"][0]