from django.contrib import admin
from django.contrib.admin import action
from django.utils.safestring import mark_safe
from . import models


@admin.register(models.StateParameter)
class StateParameterAdmin(admin.ModelAdmin):
    """工艺参数管理"""
    list_display = (
        'id', 
        'key', 
        'value', 
        'is_required',
        'is_image_path',
        'state_list',
        'description', 
        'attachment_preview', 
    )
    search_fields = ('key', 'description')
    list_filter = ('is_required', 'is_image_path', 'created_at', 'updated_at', 'states__processes__name')
    readonly_fields = ('attachment_preview_detail', 'value_preview')
    
    @admin.display(description='附件')
    def attachment_preview(self, obj):
        """列表中显示是否有附件"""
        if obj.attachment:
            return '有'
        return '无'

    @admin.display(description='所属节点')
    def state_list(self, obj):
        """显示关联的状态节点"""
        states = obj.states.all()
        if states:
            return mark_safe('<br>'.join([f"{state.name}" for state in states]))
        return '-'
    
    def attachment_preview_detail(self, obj):
        """详情页显示附件预览"""
        if obj.attachment:
            if obj.attachment.name.lower().endswith(('.png', '.jpg', '.jpeg', '.gif', '.bmp', '.webp')):
                return mark_safe(f'<img src="{obj.attachment.url}" style="max-width: 400px; max-height: 400px;" />')
            else:
                return mark_safe(f'<a href="{obj.attachment.url}" target="_blank">下载附件</a>')
        return "-"
    attachment_preview_detail.short_description = '附件预览'
    
    def value_preview(self, obj):
        """如果标记为图片路径，则显示图片预览"""
        if obj.is_image_path and obj.value:
            # 假设 value 是图片 URL
            return mark_safe(f'<img src="{obj.value}" style="max-width: 400px; max-height: 400px;" onerror="this.style.display=\'none\'; this.parentNode.innerHTML+=\'<span>(图片加载失败)</span>\';" />')
        return obj.value or "-"
    value_preview.short_description = 'Value预览'


class ProcessNodeInline(admin.StackedInline):
    model = models.ProcessNode
    extra = 1
    autocomplete_fields = ('state',)
    ordering = ('order',)


@admin.register(models.State)
class StateAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'description', 
        'created_at', 
        'updated_at',
        'parameter_count',
    )
    search_fields = ('name', 'description')
    list_filter = ('created_at', 'updated_at', 'processes__name')
    filter_horizontal = ('parameters',)

    @admin.display(description='参数数量')
    def parameter_count(self, obj: models.State):
        count = obj.parameters.count()
        if count > 0:
            params = obj.parameters.all()[:3]
            keys = ', '.join([p.key for p in params])
            if count > 3:
                keys += f' 等{count}个'
            return f"{count} ({keys})"
        return "0"


@admin.register(models.Process)
class ProcessAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'node_count',
        'description', 
        'updated_at',
    )
    search_fields = ('name', 'description')
    list_filter = ('created_at', 'updated_at')
    inlines = [ProcessNodeInline]

    @admin.display(description='节点数量')
    def node_count(self, obj: models.Process):
        return obj.process_nodes.count()


class StateFlowRecordInline(admin.StackedInline):
    model = models.StateFlowRecord
    extra = 0
    fields = ('state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    readonly_fields = ('completed_at', 'completed_by', 'cancelled_at')
    can_delete = False
    ordering = ('completed_at',)


@admin.register(models.BusinessObject)
class BusinessObjectAdmin(admin.ModelAdmin):
    list_display = (
        'id', 
        'name', 
        'process',
        'content_object_display',
        'current_state_display', 
        'progress',
        'params',
        'updated_at',
    )
    search_fields = ('name', 'description')
    list_filter = ('process', 'created_at', 'updated_at')
    actions = ['advance_to_next_state_action', 'step_back_one_state_action', 'reset_progress_action']
    autocomplete_fields = ('process',)
    inlines = [StateFlowRecordInline]
    fieldsets = [
        ('基本信息', {
            'fields': ['name', 'process', 'description']
        }),
        ('关联对象（可选）', {
            'fields': ['content_type', 'object_id'],
            'description': '可选择关联到实际的业务对象，如订单、工单等'
        }),
    ]

    @admin.display(description='关联对象')
    def content_object_display(self, obj: models.BusinessObject):
        """显示关联对象"""
        if obj.content_object:
            return f"{obj.content_type} #{obj.object_id}"
        return "-"
    
    @action(description='前进到下一个状态')
    def advance_to_next_state_action(self, request, queryset):
        from . import services
        success_count = 0
        messages = []
        
        for obj in queryset:
            success, message, _ = services.advance_to_next_state(obj, request.user)
            if success:
                success_count += 1
            messages.append(f"{obj.name}: {message}")
        
        self.message_user(request, f'成功推进 {success_count}/{queryset.count()} 个业务对象。详情: {"; ".join(messages[:5])}')

    @action(description='回退一步')
    def step_back_one_state_action(self, request, queryset):
        from . import services
        success_count = 0
        messages = []
        
        for obj in queryset:
            success, message = services.step_back_one_state(obj, request.user)
            if success:
                success_count += 1
            messages.append(f"{obj.name}: {message}")
        
        self.message_user(request, f'成功回退 {success_count}/{queryset.count()} 个业务对象。详情: {"; ".join(messages[:5])}')

    @action(description='重置进度')
    def reset_progress_action(self, request, queryset):
        from . import services
        for obj in queryset:
            services.reset_business_object_progress(obj)
        self.message_user(request, f'已重置 {queryset.count()} 个业务对象的进度。')

    @admin.display(description='当前状态', ordering='process')
    def current_state_display(self, obj: models.BusinessObject):
        from . import services
        current_state = obj.get_current_state()
        overall_status = services.get_overall_status(obj)
        
        if overall_status == 'not_started':
            return '未开始'
        elif overall_status == 'completed':
            return f'已完成 ({current_state.name if current_state else "-"})'
        elif current_state:
            # 显示最后完成的状态
            return f'进行中 (已完成: {current_state.name})'
        return '-'

    @admin.display(description='进度')
    def progress(self, obj: models.BusinessObject):
        return f"{obj.get_progress_percentage():.1f}%"

    @admin.display(description='最后完成状态参数')
    def params(self, obj: models.BusinessObject):
        """显示最后完成状态的参数"""
        current_state = obj.get_current_state()
        if current_state:
            params = current_state.parameters.all()
            if params:
                return ", ".join([f"{param.key}={param.value}" for param in params])
        return "-"


@admin.register(models.StateFlowRecord)
class StateFlowRecordAdmin(admin.ModelAdmin):
    list_display = ('id', 'business_object', 'state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    search_fields = ('business_object__name', 'state__name')
    list_filter = ('state', 'is_cancelled', 'completed_at', 'completed_by')
    readonly_fields = ('business_object', 'state', 'completed_at', 'completed_by', 'cancelled_at')
    fields = ('business_object', 'state', 'completed_at', 'completed_by', 'is_cancelled', 'cancelled_at')
    autocomplete_fields = ('business_object', 'state', 'completed_by')