# -*- coding: utf-8 -*-

import ast
from dateutil.relativedelta import relativedelta
from odoo.exceptions import ValidationError
from odoo import api, fields, models, SUPERUSER_ID, _
from odoo.exceptions import UserError
from odoo.osv import expression


class MaintenanceStage(models.Model):
    """ Model for case stages. This models the main stages of a Maintenance Request management flow. """

    _name = 'maintenance.stage'
    _description = 'Maintenance Stage'
    _order = 'sequence, id'

    name = fields.Char('Name', required=True, translate=True)
    sequence = fields.Integer('Sequence', default=20)
    fold = fields.Boolean('Folded in Maintenance Pipe')
    done = fields.Boolean('Request Done')


class MaintenanceEquipmentCategory(models.Model):
    _name = 'maintenance.equipment.category'
    _inherit = ['mail.alias.mixin', 'mail.thread']
    _description = 'Maintenance Equipment Category'

    @api.depends('equipment_ids')
    def _compute_fold(self):
        # fix mutual dependency: 'fold' depends on 'equipment_count', which is
        # computed with a read_group(), which retrieves 'fold'!
        self.fold = False
        for category in self:
            category.fold = False if category.equipment_count else True

    name = fields.Char('Category Name', required=True, translate=True)
    company_id = fields.Many2one('res.company', string='Company',
        default=lambda self: self.env.company)
    technician_user_id = fields.Many2one('res.users', 'Responsible', tracking=True, default=lambda self: self.env.uid)
    color = fields.Integer('Color Index')
    note = fields.Html('Comments', translate=True)
    equipment_ids = fields.One2many('maintenance.equipment', 'category_id', string='Equipment', copy=False)
    equipment_count = fields.Integer(string="Equipment Count", compute='_compute_equipment_count')
    maintenance_ids = fields.One2many('maintenance.request', 'category_id', copy=False)
    maintenance_count = fields.Integer(string="Maintenance Count", compute='_compute_maintenance_count')
    maintenance_open_count = fields.Integer(string="Current Maintenance", compute='_compute_maintenance_count')
    alias_id = fields.Many2one(help="Email alias for this equipment category. New emails will automatically "
        "create a new equipment under this category.")
    fold = fields.Boolean(string='Folded in Maintenance Pipe', compute='_compute_fold', store=True)

    def _compute_equipment_count(self):
        equipment_data = self.env['maintenance.equipment']._read_group([('category_id', 'in', self.ids)], ['category_id'], ['__count'])
        mapped_data = {category.id: count for category, count in equipment_data}
        for category in self:
            category.equipment_count = mapped_data.get(category.id, 0)

    def _compute_maintenance_count(self):
        maintenance_data = self.env['maintenance.request']._read_group([('category_id', 'in', self.ids)], ['category_id', 'archive'], ['__count'])
        mapped_data = {(category.id, archive): count for category, archive, count in maintenance_data}
        for category in self:
            category.maintenance_open_count = mapped_data.get((category.id, False), 0)
            category.maintenance_count = category.maintenance_open_count + mapped_data.get((category.id, True), 0)

    @api.ondelete(at_uninstall=False)
    def _unlink_except_contains_maintenance_requests(self):
        for category in self:
            if category.equipment_ids or category.maintenance_ids:
                raise UserError(_("You cannot delete an equipment category containing equipment or maintenance requests."))

    def _alias_get_creation_values(self):
        values = super(MaintenanceEquipmentCategory, self)._alias_get_creation_values()
        values['alias_model_id'] = self.env['ir.model']._get('maintenance.request').id
        if self.id:
            values['alias_defaults'] = defaults = ast.literal_eval(self.alias_defaults or "{}")
            defaults['category_id'] = self.id
        return values


class MaintenanceMixin(models.AbstractModel):
    _name = 'maintenance.mixin'
    _check_company_auto = True
    _description = 'Maintenance Maintained Item'

    company_id = fields.Many2one('res.company', string='Company',
        default=lambda self: self.env.company)
    effective_date = fields.Date('Effective Date', default=fields.Date.context_today, required=True, help="This date will be used to compute the Mean Time Between Failure.")
    maintenance_team_id = fields.Many2one('maintenance.team', string='Maintenance Team', compute='_compute_maintenance_team_id', store=True, readonly=False, check_company=True)
    technician_user_id = fields.Many2one('res.users', string='Technician', tracking=True)
    maintenance_ids = fields.One2many('maintenance.request')  # needs to be extended in order to specify inverse_name !
    maintenance_count = fields.Integer(compute='_compute_maintenance_count', string="Maintenance Count", store=True)
    maintenance_open_count = fields.Integer(compute='_compute_maintenance_count', string="Current Maintenance", store=True)
    expected_mtbf = fields.Integer(string='Expected MTBF', help='Expected Mean Time Between Failure')
    mtbf = fields.Integer(compute='_compute_maintenance_request', string='MTBF', help='Mean Time Between Failure, computed based on done corrective maintenances.')
    mttr = fields.Integer(compute='_compute_maintenance_request', string='MTTR', help='Mean Time To Repair')
    estimated_next_failure = fields.Date(compute='_compute_maintenance_request', string='Estimated time before next failure (in days)', help='Computed as Latest Failure Date + MTBF')
    latest_failure_date = fields.Date(compute='_compute_maintenance_request', string='Latest Failure Date')

    @api.depends('company_id')
    def _compute_maintenance_team_id(self):
        for record in self:
            if record.maintenance_team_id.company_id and record.maintenance_team_id.company_id.id != record.company_id.id:
                record.maintenance_team_id = False

    @api.depends('effective_date', 'maintenance_ids.stage_id', 'maintenance_ids.close_date', 'maintenance_ids.request_date')
    def _compute_maintenance_request(self):
        for record in self:
            maintenance_requests = record.maintenance_ids.filtered(lambda mr: mr.maintenance_type == 'corrective' and mr.stage_id.done)
            record.mttr = len(maintenance_requests) and (sum(int((request.close_date - request.request_date).days) for request in maintenance_requests) / len(maintenance_requests)) or 0
            record.latest_failure_date = max((request.request_date for request in maintenance_requests), default=False)
            record.mtbf = record.latest_failure_date and (record.latest_failure_date - record.effective_date).days / len(maintenance_requests) or 0
            record.estimated_next_failure = record.mtbf and record.latest_failure_date + relativedelta(days=record.mtbf) or False

    @api.depends('maintenance_ids.stage_id.done', 'maintenance_ids.archive')
    def _compute_maintenance_count(self):
        for record in self:
            record.maintenance_count = len(record.maintenance_ids)
            record.maintenance_open_count = len(record.maintenance_ids.filtered(lambda mr: not mr.stage_id.done and not mr.archive))


class MaintenanceEquipment(models.Model):
    _name = 'maintenance.equipment'
    _inherit = ['mail.thread', 'mail.activity.mixin', 'maintenance.mixin']
    _description = 'Maintenance Equipment'
    _check_company_auto = True

    def _track_subtype(self, init_values):
        self.ensure_one()
        if 'owner_user_id' in init_values and self.owner_user_id:
            return self.env.ref('maintenance.mt_mat_assign')
        return super(MaintenanceEquipment, self)._track_subtype(init_values)

    @api.depends('serial_no')
    def _compute_display_name(self):
        for record in self:
            if record.serial_no:
                record.display_name = record.name + '/' + record.serial_no
            else:
                record.display_name = record.name

    @api.model
    def _name_search(self, name, domain=None, operator='ilike', limit=None, order=None):
        domain = domain or []
        query = None
        if name and operator not in expression.NEGATIVE_TERM_OPERATORS and operator != '=':
            query = self._search([('name', '=', name)] + domain, limit=limit, order=order)
        return query or super()._name_search(name, domain, operator, limit, order)

    name = fields.Char('Equipment Name', required=True, translate=True)
    active = fields.Boolean(default=True)
    owner_user_id = fields.Many2one('res.users', string='Owner', tracking=True)
    category_id = fields.Many2one('maintenance.equipment.category', string='Equipment Category',
                                  tracking=True, group_expand='_read_group_category_ids')
    partner_id = fields.Many2one('res.partner', string='Vendor', check_company=True)
    partner_ref = fields.Char('Vendor Reference')
    location = fields.Char('Location')
    model = fields.Char('Model')
    serial_no = fields.Char('Serial Number', copy=False)
    assign_date = fields.Date('Assigned Date', tracking=True)
    cost = fields.Float('Cost')
    note = fields.Html('Note')
    warranty_date = fields.Date('Warranty Expiration Date')
    color = fields.Integer('Color Index')
    scrap_date = fields.Date('Scrap Date')
    maintenance_ids = fields.One2many('maintenance.request', 'equipment_id')

    @api.onchange('category_id')
    def _onchange_category_id(self):
        self.technician_user_id = self.category_id.technician_user_id

    _sql_constraints = [
        ('serial_no', 'unique(serial_no)', "Another asset already exists with this serial number!"),
    ]

    @api.model_create_multi
    def create(self, vals_list):
        equipments = super().create(vals_list)
        for equipment in equipments:
            if equipment.owner_user_id:
                equipment.message_subscribe(partner_ids=[equipment.owner_user_id.partner_id.id])
        return equipments

    def write(self, vals):
        if vals.get('owner_user_id'):
            self.message_subscribe(partner_ids=self.env['res.users'].browse(vals['owner_user_id']).partner_id.ids)
        return super(MaintenanceEquipment, self).write(vals)

    @api.model
    def _read_group_category_ids(self, categories, domain, order):
        """ Read group customization in order to display all the categories in
            the kanban view, even if they are empty.
        """
        category_ids = categories._search([], order=order, access_rights_uid=SUPERUSER_ID)
        return categories.browse(category_ids)


class MaintenanceRequest(models.Model):
    _name = 'maintenance.request'
    _inherit = ['mail.thread.cc', 'mail.activity.mixin']
    _description = 'Maintenance Request'
    _order = "id desc"
    _check_company_auto = True

    @api.returns('self')
    def _default_stage(self):
        return self.env['maintenance.stage'].search([], limit=1)

    def _creation_subtype(self):
        return self.env.ref('maintenance.mt_req_created')

    def _track_subtype(self, init_values):
        self.ensure_one()
        if 'stage_id' in init_values:
            return self.env.ref('maintenance.mt_req_status')
        return super(MaintenanceRequest, self)._track_subtype(init_values)

    def _get_default_team_id(self):
        MT = self.env['maintenance.team']
        team = MT.search([('company_id', '=', self.env.company.id)], limit=1)
        if not team:
            team = MT.search([], limit=1)
        return team.id

    name = fields.Char('Subjects', required=True)
    company_id = fields.Many2one('res.company', string='Company', required=True,
        default=lambda self: self.env.company)
    description = fields.Html('Description')
    request_date = fields.Date('Request Date', tracking=True, default=fields.Date.context_today,
                               help="Date requested for the maintenance to happen")
    owner_user_id = fields.Many2one('res.users', string='Created by User', default=lambda s: s.env.uid)
    category_id = fields.Many2one('maintenance.equipment.category', related='equipment_id.category_id', string='Category', store=True, readonly=True)
    equipment_id = fields.Many2one('maintenance.equipment', string='Equipment',
                                   ondelete='restrict', index=True, check_company=True)
    user_id = fields.Many2one('res.users', string='Technician', compute='_compute_user_id', store=True, readonly=False, tracking=True)
    stage_id = fields.Many2one('maintenance.stage', string='Stage', ondelete='restrict', tracking=True,
                               group_expand='_read_group_stage_ids', default=_default_stage, copy=False)
    priority = fields.Selection([('0', 'Very Low'), ('1', 'Low'), ('2', 'Normal'), ('3', 'High')], string='Priority')
    color = fields.Integer('Color Index')
    close_date = fields.Date('Close Date', help="Date the maintenance was finished. ")
    kanban_state = fields.Selection([('normal', 'In Progress'), ('blocked', 'Blocked'), ('done', 'Ready for next stage')],
                                    string='Kanban State', required=True, default='normal', tracking=True)
    # active = fields.Boolean(default=True, help="Set active to false to hide the maintenance request without deleting it.")
    archive = fields.Boolean(default=False, help="Set archive to true to hide the maintenance request without deleting it.")
    maintenance_type = fields.Selection([('corrective', 'Corrective'), ('preventive', 'Preventive')], string='Maintenance Type', default="corrective")
    schedule_date = fields.Datetime('Scheduled Date', help="Date the maintenance team plans the maintenance.  It should not differ much from the Request Date. ")
    maintenance_team_id = fields.Many2one('maintenance.team', string='Team', required=True, default=_get_default_team_id,
                                          compute='_compute_maintenance_team_id', store=True, readonly=False, check_company=True)
    duration = fields.Float(help="Duration in hours.")
    done = fields.Boolean(related='stage_id.done')
    instruction_type = fields.Selection([
        ('pdf', 'PDF'), ('google_slide', 'Google Slide'), ('text', 'Text')],
        string="Instruction", default="text"
    )
    instruction_pdf = fields.Binary('PDF')
    instruction_google_slide = fields.Char('Google Slide', help="Paste the url of your Google Slide. Make sure the access to the document is public.")
    instruction_text = fields.Html('Text')
    recurring_maintenance = fields.Boolean(string="Recurrent", compute='_compute_recurring_maintenance', store=True, readonly=False)
    repeat_interval = fields.Integer(string='Repeat Every', default=1)
    repeat_unit = fields.Selection([
        ('day', 'Days'),
        ('week', 'Weeks'),
        ('month', 'Months'),
        ('year', 'Years'),
    ], default='week')
    repeat_type = fields.Selection([
        ('forever', 'Forever'),
        ('until', 'Until'),
    ], default="forever", string="Until")
    repeat_until = fields.Date(string="End Date")

    def archive_equipment_request(self):
        self.write({'archive': True, 'recurring_maintenance': False})

    def reset_equipment_request(self):
        """ Reinsert the maintenance request into the maintenance pipe in the first stage"""
        first_stage_obj = self.env['maintenance.stage'].search([], order="sequence asc", limit=1)
        # self.write({'active': True, 'stage_id': first_stage_obj.id})
        self.write({'archive': False, 'stage_id': first_stage_obj.id})

    @api.constrains('repeat_interval')
    def _check_repeat_interval(self):
        for record in self:
            if record.repeat_interval < 1:
                raise ValidationError("Repeat Interval cannot be less than 1.")

    @api.depends('company_id', 'equipment_id')
    def _compute_maintenance_team_id(self):
        for request in self:
            if request.equipment_id and request.equipment_id.maintenance_team_id:
                request.maintenance_team_id = request.equipment_id.maintenance_team_id.id
            if request.maintenance_team_id.company_id and request.maintenance_team_id.company_id.id != request.company_id.id:
                request.maintenance_team_id = False

    @api.depends('company_id', 'equipment_id')
    def _compute_user_id(self):
        for request in self:
            if request.equipment_id:
                request.user_id = request.equipment_id.technician_user_id or request.equipment_id.category_id.technician_user_id
            if request.user_id and request.company_id.id not in request.user_id.company_ids.ids:
                request.user_id = False

    @api.depends('maintenance_type')
    def _compute_recurring_maintenance(self):
        for request in self:
            if request.maintenance_type != 'preventive':
                request.recurring_maintenance = False

    @api.model_create_multi
    def create(self, vals_list):
        # context: no_log, because subtype already handle this
        maintenance_requests = super().create(vals_list)
        for request in maintenance_requests:
            if request.owner_user_id or request.user_id:
                request._add_followers()
            if request.equipment_id and not request.maintenance_team_id:
                request.maintenance_team_id = request.equipment_id.maintenance_team_id
            if request.close_date and not request.stage_id.done:
                request.close_date = False
            if not request.close_date and request.stage_id.done:
                request.close_date = fields.Date.today()
        maintenance_requests.activity_update()
        return maintenance_requests

    def write(self, vals):
        # Overridden to reset the kanban_state to normal whenever
        # the stage (stage_id) of the Maintenance Request changes.
        if vals and 'kanban_state' not in vals and 'stage_id' in vals:
            vals['kanban_state'] = 'normal'
        if 'stage_id' in vals and self.maintenance_type == 'preventive' and self.recurring_maintenance and self.env['maintenance.stage'].browse(vals['stage_id']).done:
            schedule_date = self.schedule_date or fields.Datetime.now()
            schedule_date += relativedelta(**{f"{self.repeat_unit}s": self.repeat_interval})
            if self.repeat_type == 'forever' or schedule_date.date() <= self.repeat_until:
                self.copy({'schedule_date': schedule_date})
        res = super(MaintenanceRequest, self).write(vals)
        if vals.get('owner_user_id') or vals.get('user_id'):
            self._add_followers()
        if 'stage_id' in vals:
            self.filtered(lambda m: m.stage_id.done).write({'close_date': fields.Date.today()})
            self.filtered(lambda m: not m.stage_id.done).write({'close_date': False})
            self.activity_feedback(['maintenance.mail_act_maintenance_request'])
            self.activity_update()
        if vals.get('user_id') or vals.get('schedule_date'):
            self.activity_update()
        if self._need_new_activity(vals):
            # need to change description of activity also so unlink old and create new activity
            self.activity_unlink(['maintenance.mail_act_maintenance_request'])
            self.activity_update()
        return res

    def _need_new_activity(self, vals):
        return vals.get('equipment_id')

    def _get_activity_note(self):
        self.ensure_one()
        if self.equipment_id:
            return _('Request planned for %s', self.equipment_id._get_html_link())
        return False

    def activity_update(self):
        """ Update maintenance activities based on current record set state.
        It reschedule, unlink or create maintenance request activities. """
        self.filtered(lambda request: not request.schedule_date).activity_unlink(['maintenance.mail_act_maintenance_request'])
        for request in self.filtered(lambda request: request.schedule_date):
            date_dl = fields.Datetime.from_string(request.schedule_date).date()
            updated = request.activity_reschedule(
                ['maintenance.mail_act_maintenance_request'],
                date_deadline=date_dl,
                new_user_id=request.user_id.id or request.owner_user_id.id or self.env.uid)
            if not updated:
                note = self._get_activity_note()
                request.activity_schedule(
                    'maintenance.mail_act_maintenance_request',
                    fields.Datetime.from_string(request.schedule_date).date(),
                    note=note, user_id=request.user_id.id or request.owner_user_id.id or self.env.uid)

    def _add_followers(self):
        for request in self:
            partner_ids = (request.owner_user_id.partner_id + request.user_id.partner_id).ids
            request.message_subscribe(partner_ids=partner_ids)

    @api.model
    def _read_group_stage_ids(self, stages, domain, order):
        """ Read group customization in order to display all the stages in the
            kanban view, even if they are empty
        """
        stage_ids = stages._search([], order=order, access_rights_uid=SUPERUSER_ID)
        return stages.browse(stage_ids)


class MaintenanceTeam(models.Model):
    _name = 'maintenance.team'
    _description = 'Maintenance Teams'

    name = fields.Char('Team Name', required=True, translate=True)
    active = fields.Boolean(default=True)
    company_id = fields.Many2one('res.company', string='Company',
        default=lambda self: self.env.company)
    member_ids = fields.Many2many(
        'res.users', 'maintenance_team_users_rel', string="Team Members",
        domain="[('company_ids', 'in', company_id)]")
    color = fields.Integer("Color Index", default=0)
    request_ids = fields.One2many('maintenance.request', 'maintenance_team_id', copy=False)
    equipment_ids = fields.One2many('maintenance.equipment', 'maintenance_team_id', copy=False)

    # For the dashboard only
    todo_request_ids = fields.One2many('maintenance.request', string="Requests", copy=False, compute='_compute_todo_requests')
    todo_request_count = fields.Integer(string="Number of Requests", compute='_compute_todo_requests')
    todo_request_count_date = fields.Integer(string="Number of Requests Scheduled", compute='_compute_todo_requests')
    todo_request_count_high_priority = fields.Integer(string="Number of Requests in High Priority", compute='_compute_todo_requests')
    todo_request_count_block = fields.Integer(string="Number of Requests Blocked", compute='_compute_todo_requests')
    todo_request_count_unscheduled = fields.Integer(string="Number of Requests Unscheduled", compute='_compute_todo_requests')

    @api.depends('request_ids.stage_id.done')
    def _compute_todo_requests(self):
        for team in self:
            team.todo_request_ids = self.env['maintenance.request'].search([('maintenance_team_id', '=', team.id), ('stage_id.done', '=', False), ('archive', '=', False)])
            data = self.env['maintenance.request']._read_group(
                [('maintenance_team_id', '=', team.id), ('stage_id.done', '=', False), ('archive', '=', False)],
                ['schedule_date:year', 'priority', 'kanban_state'],
                ['__count']
            )
            team.todo_request_count = sum(count for (_, _, _, count) in data)
            team.todo_request_count_date = sum(count for (schedule_date, _, _, count) in data if schedule_date)
            team.todo_request_count_high_priority = sum(count for (_, priority, _, count) in data if priority == 3)
            team.todo_request_count_block = sum(count for (_, _, kanban_state, count) in data if kanban_state == 'blocked')
            team.todo_request_count_unscheduled = team.todo_request_count - team.todo_request_count_date

    @api.depends('equipment_ids')
    def _compute_equipment(self):
        for team in self:
            team.equipment_count = len(team.equipment_ids)
