"""Style the A417 boreholes in QGIS: categorised symbols, labels, an HTML map tip and a saved project.

Part 2 of the TechnicalGIS series "AGS data in GIS". Run boreholes_map.py first, then run this with
the QGIS Python launcher, for example on Windows:
    "C:\\Program Files\\QGIS 3.40.12\\bin\\python-qgis-ltr.bat" qgis_borehole_map.py
It writes output/a417_boreholes.qgz (open it in QGIS Desktop) and renders output/04-qgis-borehole-map.png.
Tested with QGIS 3.40.12-Bratislava.

Data: A417 Missing Link ground investigation (BGS deposited data item 173984), Open Government Licence
v3.0, contains British Geological Survey materials © UKRI 2026. Environment Agency LIDAR Composite DTM
(Open Government Licence v3).
"""
from pathlib import Path

from qgis.core import (
    Qgis,
    QgsApplication,
    QgsCategorizedSymbolRenderer,
    QgsCoordinateReferenceSystem,
    QgsMapRendererParallelJob,
    QgsMapSettings,
    QgsMarkerSymbol,
    QgsPalLayerSettings,
    QgsProject,
    QgsRasterLayer,
    QgsRectangle,
    QgsRendererCategory,
    QgsTextBufferSettings,
    QgsTextFormat,
    QgsVectorLayer,
    QgsVectorLayerSimpleLabeling,
)
from qgis.PyQt.QtCore import QPoint, QSize, Qt
from qgis.PyQt.QtGui import QColor, QFont, QPainter

OUT = Path(__file__).parent / "output"
CREDIT = ("Contains Environment Agency information © Environment Agency and database right; "
          "BGS © UKRI (OGL v3)")

# Same colours as boreholes_map.py
TYPE_COLOURS = {"RC": "#1f78b4", "TP": "#e6550d", "CPT": "#31a354", "RO": "#756bb1", "CP": "#d62728"}

# The map tip: a header from LOCA, a few summary fields, then the hole's log as the HTML table
# that boreholes_map.py stored in the log_html field.
MAP_TIP = """<div style="font-family:sans-serif;font-size:12px;min-width:260px">
<b style="font-size:14px">[% "LOCA_ID" %]</b> &middot; [% "type_name" %]<br>
Ground level [% format_number("LOCA_GL", 2) %] m OD (LIDAR [% format_number("lidar_gl", 2) %])<br>
Final depth [% format_number("LOCA_FDEP", 2) %] m
[% CASE WHEN "rockhead_depth" IS NOT NULL
   THEN '&middot; rock at ' || format_number("rockhead_depth", 2) || ' m (' || "rockhead_name" || ')' END %]<br>
[% CASE WHEN "first_water_strike" IS NOT NULL
   THEN 'First water strike ' || format_number("first_water_strike", 2) || ' m<br>' END %]
[% "n_samples" %] samples, [% "n_spt" %] SPTs
<hr style="margin:4px 0">[% "log_html" %]</div>"""


def main() -> None:
    qgs = QgsApplication([], False)
    qgs.initQgis()
    print("QGIS", Qgis.version())
    project = QgsProject.instance()
    project.setCrs(QgsCoordinateReferenceSystem("EPSG:27700"))

    shade = QgsRasterLayer(str(OUT / "a417_hillshade.tif"), "LIDAR hillshade")
    holes = QgsVectorLayer(f"{OUT / 'a417_boreholes.gpkg'}|layername=boreholes", "A417 exploratory holes", "ogr")
    print(f"hillshade valid={shade.isValid()} | boreholes valid={holes.isValid()}, "
          f"{holes.featureCount()} features, CRS {holes.crs().authid()}")

    # One symbol per LOCA_TYPE, labelled with the description from the ABBR group.
    names = {f["LOCA_TYPE"]: f["type_name"] for f in holes.getFeatures()}
    categories = []
    for code, colour in TYPE_COLOURS.items():
        symbol = QgsMarkerSymbol.createSimple({"name": "circle", "color": colour, "outline_color": "white",
                                               "outline_width": "0.3", "size": "2.6"})
        categories.append(QgsRendererCategory(code, symbol, f"{code}: {names.get(code, code)}"))
    holes.setRenderer(QgsCategorizedSymbolRenderer("LOCA_TYPE", categories))

    # Label every hole with its LOCA_ID, haloed so it reads over the hillshade.
    fmt = QgsTextFormat()
    fmt.setFont(QFont("Arial"))
    fmt.setSize(7)
    buffer = QgsTextBufferSettings()
    buffer.setEnabled(True)
    buffer.setSize(0.8)
    buffer.setColor(QColor("white"))
    fmt.setBuffer(buffer)
    label = QgsPalLayerSettings()
    label.fieldName = "LOCA_ID"
    label.placement = Qgis.LabelPlacement.AroundPoint
    label.setFormat(fmt)
    holes.setLabeling(QgsVectorLayerSimpleLabeling(label))
    holes.setLabelsEnabled(True)

    holes.setDisplayExpression('"LOCA_ID"')
    holes.setMapTipTemplate(MAP_TIP)
    project.addMapLayers([shade, holes], False)
    root = project.layerTreeRoot()
    root.addLayer(holes)                    # first in the tree draws on top
    root.addLayer(shade)
    # Credit the data on every map: as layer attribution, and as QGIS Desktop's copyright decoration
    # (View > Decorations > Copyright Label), which the project remembers.
    shade.serverProperties().setAttribution("© Environment Agency, Open Government Licence v3")
    holes.serverProperties().setAttribution("Contains British Geological Survey materials © UKRI, Open Government Licence v3")
    project.writeEntry("CopyrightLabel", "/Enabled", True)
    project.writeEntry("CopyrightLabel", "/Label", CREDIT)
    project.write(str(OUT / "a417_boreholes.qgz"))
    print("saved output/a417_boreholes.qgz with the style, labels and map tip")

    # Render the busiest part of the site, the top of Crickley Hill, at a scale where labels fit.
    settings = QgsMapSettings()
    settings.setLayers([holes, shade])
    settings.setDestinationCrs(project.crs())
    settings.setExtent(QgsRectangle(392_700, 215_500, 393_900, 216_500))
    settings.setOutputSize(QSize(1500, 1250))
    settings.setOutputDpi(150)
    settings.setBackgroundColor(QColor("white"))
    job = QgsMapRendererParallelJob(settings)
    job.start()
    job.waitForFinished()
    image = job.renderedImage()
    painter = QPainter(image)
    painter.setFont(QFont("Arial", 7))
    box = painter.fontMetrics().boundingRect(CREDIT).adjusted(-6, -4, 6, 4)
    box.moveBottomLeft(QPoint(8, image.height() - 8))
    painter.fillRect(box, QColor(255, 255, 255, 220))
    painter.setPen(QColor("#333333"))
    painter.drawText(box, Qt.AlignCenter, CREDIT)
    painter.end()
    image.save(str(OUT / "04-qgis-borehole-map.png"))
    print(f"rendered 04-qgis-borehole-map.png at 1:{settings.scale():,.0f}; render errors: {len(job.errors())}")
    qgs.exitQgis()


if __name__ == "__main__":
    main()