from django.contrib import admin
from .models import (
    UserProfile, Project, Worker, Team, WorkLog,
    PayrollRecord, Loan, PayrollAdjustment,
    ExpenseReceipt, ExpenseLineItem,
    WorkerCertificate, WorkerWarning,
    SiteReport,
    Absence,
)

@admin.register(UserProfile)
class UserProfileAdmin(admin.ModelAdmin):
    list_display = ('user',)
    search_fields = ('user__username', 'user__first_name', 'user__last_name')

@admin.register(Project)
class ProjectAdmin(admin.ModelAdmin):
    list_display = ('name', 'active')
    list_filter = ('active',)
    search_fields = ('name', 'description')
    filter_horizontal = ('supervisors',)

# === INLINE ADMINS FOR WORKER ===
# Let admins manage a worker's certifications and warnings directly
# from the Worker change page, without navigating to a separate screen.
class WorkerCertificateInline(admin.TabularInline):
    model = WorkerCertificate
    extra = 0  # no blank rows by default — admin clicks "Add another" to create
    readonly_fields = ('created_at',)
    fields = ('cert_type', 'document', 'issued_date', 'valid_until', 'notes', 'created_at')


class WorkerWarningInline(admin.TabularInline):
    model = WorkerWarning
    extra = 0
    readonly_fields = ('created_at',)
    fields = ('date', 'severity', 'reason', 'description', 'issued_by', 'document', 'created_at')


@admin.register(Worker)
class WorkerAdmin(admin.ModelAdmin):
    list_display = ('name', 'id_number', 'monthly_salary', 'active')
    list_filter = ('active', 'has_drivers_license')
    search_fields = ('name', 'id_number', 'phone_number')

    # Inline sections for certs + warnings appear below the main Worker form
    inlines = [WorkerCertificateInline, WorkerWarningInline]

    # === FIELDSETS ===
    # Organise the worker edit form into clear sections.
    # Banking & Tax fields (UIF, Bank, Acc No.) live inside Personal Info
    # per product requirement — help_text strings render as hints under
    # each field in admin (and as tooltips on the friendly edit page).
    fieldsets = (
        ('Personal Info', {
            'fields': ('name', 'id_number', 'phone_number', 'monthly_salary',
                       'tax_number', 'uif_number',
                       'bank_name', 'bank_account_number',
                       'employment_date', 'active', 'notes'),
        }),
        ('Sizing', {
            'fields': ('shoe_size', 'overall_top_size', 'pants_size', 'tshirt_size'),
        }),
        ('Documents & License', {
            'fields': ('photo', 'id_document',
                       'has_drivers_license', 'drivers_license', 'drivers_license_code'),
        }),
    )


# === STANDALONE ADMINS FOR CERTS + WARNINGS ===
# Separate pages for bulk operations across workers — "show me all
# certs expiring this month" or "show me all final warnings".
@admin.register(WorkerCertificate)
class WorkerCertificateAdmin(admin.ModelAdmin):
    list_display = ('worker', 'cert_type', 'issued_date', 'valid_until', 'is_expired')
    list_filter = ('cert_type',)
    search_fields = ('worker__name', 'worker__id_number')
    date_hierarchy = 'valid_until'


@admin.register(WorkerWarning)
class WorkerWarningAdmin(admin.ModelAdmin):
    list_display = ('worker', 'date', 'severity', 'reason', 'issued_by')
    list_filter = ('severity',)
    search_fields = ('worker__name', 'reason', 'description')
    date_hierarchy = 'date'

@admin.register(Absence)
class AbsenceAdmin(admin.ModelAdmin):
    # `project` shown alongside reason/is_paid so the admin index reads as
    # "worker — project — reason — paid" at a glance.
    list_display = ('worker', 'project', 'date', 'reason', 'is_paid', 'logged_by', 'created_at')
    # `project` filter sits next to reason — handy for "which workers were
    # absent on Solar Farm Alpha last month".
    list_filter = ('reason', 'is_paid', 'project', 'date')
    search_fields = ('worker__name', 'worker__id_number', 'notes')
    # `project` is a small set normally but raw_id keeps the form fast
    # even if it grows. Same treatment as the other FKs.
    raw_id_fields = ('worker', 'logged_by', 'payroll_adjustment', 'project')
    readonly_fields = ('created_at', 'updated_at')
    date_hierarchy = 'date'

    # === KEEP PAYROLL ADJUSTMENT IN SYNC WITH is_paid ===
    # Without this, toggling `is_paid` via /admin/core/absence/<id>/change/
    # saves the row but does NOT create (or delete) the linked Bonus
    # PayrollAdjustment — the friendly UI (`absence_edit`) does this
    # correctly. Mirror that behavior here so the two paths are
    # consistent.
    def save_model(self, request, obj, form, change):
        super().save_model(request, obj, form, change)
        # Import the sync helper inside the method so admin.py doesn't
        # have to import from views at module load (avoids any chance
        # of circular-import surprises during Django startup).
        from .views import _sync_absence_payroll_adjustment
        try:
            _sync_absence_payroll_adjustment(obj)
        except ValueError as e:
            # The sync helper raises ValueError when the user tries to
            # un-pay an Absence whose linked adjustment has already been
            # paid (i.e. a PayrollRecord exists). Surface that to the
            # admin via the messages framework rather than blowing up.
            from django.contrib import messages
            messages.error(request, str(e))

@admin.register(Team)
class TeamAdmin(admin.ModelAdmin):
    list_display = ('name', 'supervisor', 'pay_frequency', 'pay_start_date', 'active')
    list_editable = ('pay_frequency', 'pay_start_date')
    list_filter = ('active', 'supervisor', 'pay_frequency')
    search_fields = ('name',)
    filter_horizontal = ('workers',)

@admin.register(WorkLog)
class WorkLogAdmin(admin.ModelAdmin):
    list_display = ('date', 'project', 'supervisor', 'overtime_amount')
    list_filter = ('date', 'project', 'supervisor')
    search_fields = ('project__name', 'notes')
    filter_horizontal = ('workers', 'priced_workers')

@admin.register(PayrollRecord)
class PayrollRecordAdmin(admin.ModelAdmin):
    list_display = ('worker', 'date', 'amount_paid')
    list_filter = ('date', 'worker')
    search_fields = ('worker__name',)
    filter_horizontal = ('work_logs',)

@admin.register(Loan)
class LoanAdmin(admin.ModelAdmin):
    list_display = ('worker', 'principal_amount', 'remaining_balance', 'date', 'active')
    list_filter = ('active', 'date', 'worker')
    search_fields = ('worker__name', 'reason')

@admin.register(SiteReport)
class SiteReportAdmin(admin.ModelAdmin):
    """Admin view for daily site progress reports.

    `metrics` is a JSONField — Django renders it as a textarea blob,
    which is fine for low-frequency admin edits. The friendly
    /site-report/<id>/edit/ form is the primary entry point.
    """
    list_display = ('work_log', 'weather', 'temperature_min', 'temperature_max', 'created_by', 'created_at')
    list_filter = ('weather', 'created_at', 'work_log__project')
    search_fields = ('notes', 'work_log__project__name', 'work_log__supervisor__username')
    raw_id_fields = ('work_log', 'created_by')
    readonly_fields = ('created_at', 'updated_at')


@admin.register(PayrollAdjustment)
class PayrollAdjustmentAdmin(admin.ModelAdmin):
    list_display = ('worker', 'type_display', 'amount', 'date')
    list_filter = ('type', 'date', 'worker')
    search_fields = ('worker__name', 'description')

    # === Type column uses the short user-facing label ===
    @admin.display(description='Type', ordering='type')
    def type_display(self, obj):
        """Show the short user-facing label (e.g. "Loan", "Advance")
        instead of the raw DB value ("New Loan", "Advance Payment").
        Sorting and filtering still work off the underlying `type`
        field — this only changes what's printed in the column."""
        return obj.get_type_display()

class ExpenseLineItemInline(admin.TabularInline):
    model = ExpenseLineItem
    extra = 1

@admin.register(ExpenseReceipt)
class ExpenseReceiptAdmin(admin.ModelAdmin):
    list_display = ('vendor_name', 'date', 'total_amount', 'user')
    list_filter = ('date', 'payment_method', 'vat_type')
    search_fields = ('vendor_name', 'description')
    inlines = [ExpenseLineItemInline]

@admin.register(ExpenseLineItem)
class ExpenseLineItemAdmin(admin.ModelAdmin):
    list_display = ('product_name', 'amount', 'receipt')
    search_fields = ('product_name', 'receipt__vendor_name')