feat(mailer): Use colors and logo in email templates

packages/dsw-mailer/CHANGELOG.md

@@ -7,6 +7,10 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Added
+
+- Enable to use colors and logo in email templates
+
 
 ## [4.2.1]
 

packages/dsw-mailer/dsw/mailer/mailer.py

@@ -93,17 +93,21 @@ def work(self, cmd: PersistentCommand):
             msg_id=cmd.uuid,
             trigger='PersistentComment',
         )
+        # get tenant config from DB
+        tenant_cfg = app_ctx.db.get_tenant_config(tenant_uuid=cmd.tenant_uuid)
+        LOG.debug(f'Tenant config from DB: {tenant_cfg}')
+        rq.style.from_dict(tenant_cfg.look_and_feel)
         # get mailer config from DB
-        cfg = _transform_mail_config(
+        mail_cfg = _transform_mail_config(
             cfg=app_ctx.db.get_mail_config(tenant_uuid=cmd.tenant_uuid),
         )
-        LOG.debug(f'Config from DB: {cfg}')
+        LOG.debug(f'Mail config from DB: {mail_cfg}')
         # client URL
         rq.client_url = cmd.body.get('clientUrl', app_ctx.cfg.general.client_url)
         rq.domain = urllib.parse.urlparse(rq.client_url).hostname
         # update Sentry info
         SentryReporter.set_context('template', rq.template_name)
-        self.send(rq, cfg)
+        self.send(rq, mail_cfg)
         SentryReporter.set_context('template', '-')
         SentryReporter.set_context('cmd_uuid', '-')
         Context.get().update_trace_id('-')

packages/dsw-mailer/dsw/mailer/model.py

@@ -1,6 +1,82 @@
 from typing import Optional
 
 
+class Color:
+
+    def __init__(self, color_hex: str = '#000000'):
+        h = color_hex.lstrip('#')
+        self.red, self.green, self.blue = tuple(int(h[i:i+2], 16) for i in (0, 2, 4))
+
+    @property
+    def hex(self):
+        return f'#{self.red:02x}{self.green:02x}{self.blue:02x}'
+
+    @property
+    def luminance(self):
+        # https://www.w3.org/WAI/GL/wiki/Relative_luminance
+
+        def _luminance_component(component: int):
+            c = component / 255
+            if c <= 0.03928:
+                return c / 12.92
+            else:
+                return ((c + 0.055) / 1.055) ** 2.4
+
+        r = _luminance_component(self.red)
+        g = _luminance_component(self.green)
+        b = _luminance_component(self.blue)
+        return 0.2126 * r + 0.7152 * g + 0.0722 * b
+
+    @property
+    def is_dark(self):
+        return self.luminance < 0.5
+
+    @property
+    def is_light(self):
+        return not self.is_dark
+
+    @property
+    def contrast_color(self) -> 'Color':
+        return Color('#ffffff') if self.is_dark else Color('#000000')
+
+    def __str__(self):
+        return self.hex
+
+
+class StyleConfig:
+    _DEFAULT = None
+
+    def __init__(self, logo_url: Optional[str], primary_color: str,
+                 illustration_color: str):
+        self.logo_url = logo_url
+        self.primary_color = Color(primary_color)
+        self.illustration_color = Color(illustration_color)
+
+    def from_dict(self, data: dict):
+        if data.get('logoUrl', None) is not None:
+            self.logo_url = data.get('logoUrl')
+        if data.get('primaryColor', None) is not None:
+            self.primary_color = Color(data.get(
+                'primaryColor',
+                self.default().primary_color.hex
+            ))
+        if data.get('illustrationColor', None) is not None:
+            self.illustration_color = Color(data.get(
+                'illustrationColor',
+                self.default().illustration_color.hex,
+            ))
+
+    @classmethod
+    def default(cls):
+        if cls._DEFAULT is None:
+            cls._DEFAULT = StyleConfig(
+                logo_url=None,
+                primary_color='#0033aa',
+                illustration_color='#4285f4',
+            )
+        return cls._DEFAULT
+
+
 class TemplateDescriptorPart:
 
     DEFAULTS = {
@@ -85,14 +161,16 @@ def load_from_file(data: dict) -> 'TemplateDescriptor':
 class MessageRequest:
 
     def __init__(self, message_id: str, template_name: str, trigger: str,
-                 ctx: dict, recipients: list[str]):
+                 ctx: dict, recipients: list[str], style: Optional[StyleConfig] = None):
         self.id = message_id
         self.template_name = template_name
         self.trigger = trigger
         self.ctx = ctx
         self.recipients = recipients
         self.domain = None  # type: Optional[str]
         self.client_url = ''  # type: str
+        self.style = style or StyleConfig.default()
+        self.ctx['style'] = self.style
 
     @staticmethod
     def load_from_file(data: dict) -> 'MessageRequest':
@@ -102,6 +180,11 @@ def load_from_file(data: dict) -> 'MessageRequest':
             trigger=data.get('trigger', 'input_file'),
             ctx=data.get('ctx', {}),
             recipients=data.get('recipients', []),
+            style=StyleConfig(
+                logo_url=data.get('styleLogoUrl', None),
+                primary_color=data.get('stylePrimaryColor', '#019AD6'),
+                illustration_color=data.get('styleIllustrationColor', '#019AD6'),
+            ),
         )
 
 

packages/dsw-mailer/dsw/mailer/templates.py

@@ -1,6 +1,7 @@
 import datetime
 import dateutil.parser
 import jinja2
+import jinja2.sandbox
 import json
 import logging
 import pathlib
@@ -65,7 +66,7 @@ class TemplateRegistry:
     def __init__(self, cfg: MailerConfig, workdir: pathlib.Path):
         self.cfg = cfg
         self.workdir = workdir
-        self.j2_env = jinja2.Environment(
+        self.j2_env = jinja2.sandbox.SandboxedEnvironment(
             loader=jinja2.FileSystemLoader(searchpath=workdir),
             extensions=['jinja2.ext.do'],
         )