package app

import (
    "encoding/base64"
    "encoding/json"
    "fmt"
    "reflect"
    "strings"
    "github.com/seaweedfs/seaweedfs/weed/admin/maintenance"
    "github.com/seaweedfs/seaweedfs/weed/worker/tasks"
    "github.com/seaweedfs/seaweedfs/weed/admin/config"
    "github.com/seaweedfs/seaweedfs/weed/admin/view/components"
)

// Helper function to convert task schema to JSON string
func taskSchemaToJSON(schema *tasks.TaskConfigSchema) string {
    if schema == nil {
        return "{}"
    }
    
    data := map[string]interface{}{
        "fields": schema.Fields,
    }
    
    jsonBytes, err := json.Marshal(data)
    if err != nil {
        return "{}"
    }
    
    return string(jsonBytes)
}

// Helper function to base64 encode the JSON to avoid HTML escaping issues
func taskSchemaToBase64JSON(schema *tasks.TaskConfigSchema) string {
    jsonStr := taskSchemaToJSON(schema)
    return base64.StdEncoding.EncodeToString([]byte(jsonStr))
}

templ TaskConfigSchema(data *maintenance.TaskConfigData, schema *tasks.TaskConfigSchema, config interface{}) {
    <div class="container-fluid">
        <div class="row mb-4">
            <div class="col-12">
                <div class="d-flex justify-content-between align-items-center">
                    <h2 class="mb-0">
                        <i class={schema.Icon + " me-2"}></i>
                        {schema.DisplayName} Configuration
                    </h2>
                    <div class="btn-group">
                        <a href="/maintenance/config" class="btn btn-outline-secondary">
                            <i class="fas fa-arrow-left me-1"></i>
                            Back to System Config
                        </a>
                    </div>
                </div>
            </div>
        </div>

        <!-- Configuration Card -->
        <div class="row">
            <div class="col-12">
                <div class="card">
                    <div class="card-header">
                        <h5 class="mb-0">
                            <i class="fas fa-cogs me-2"></i>
                            Task Configuration
                        </h5>
                        <p class="mb-0 text-muted small">{schema.Description}</p>
                    </div>
                    <div class="card-body">
                        <form id="taskConfigForm" method="POST">
                            <!-- Dynamically render all schema fields in defined order -->
                            for _, field := range schema.Fields {
                                @TaskConfigField(field, config)
                            }
                            
                            <div class="d-flex gap-2">
                                <button type="submit" class="btn btn-primary">
                                    <i class="fas fa-save me-1"></i>
                                    Save Configuration
                                </button>
                                <button type="button" class="btn btn-secondary" onclick="resetToDefaults()">
                                    <i class="fas fa-undo me-1"></i>
                                    Reset to Defaults
                                </button>
                            </div>
                        </form>
                    </div>
                </div>
            </div>
        </div>

        <!-- Performance Notes Card -->
        <div class="row mt-4">
            <div class="col-12">
                <div class="card">
                    <div class="card-header">
                        <h5 class="mb-0">
                            <i class="fas fa-info-circle me-2"></i>
                            Important Notes
                        </h5>
                    </div>
                    <div class="card-body">
                        <div class="alert alert-info" role="alert">
                            if schema.TaskName == "vacuum" {
                                <h6 class="alert-heading">Vacuum Operations:</h6>
                                <p class="mb-2"><strong>Performance:</strong> Vacuum operations are I/O intensive and may impact cluster performance.</p>
                                <p class="mb-2"><strong>Safety:</strong> Only volumes meeting age and garbage thresholds will be processed.</p>
                                <p class="mb-0"><strong>Recommendation:</strong> Monitor cluster load and adjust concurrent limits accordingly.</p>
                            } else if schema.TaskName == "balance" {
                                <h6 class="alert-heading">Balance Operations:</h6>
                                <p class="mb-2"><strong>Performance:</strong> Volume balancing involves data movement and can impact cluster performance.</p>
                                <p class="mb-2"><strong>Safety:</strong> Requires adequate server count to ensure data safety during moves.</p>
                                <p class="mb-0"><strong>Recommendation:</strong> Run during off-peak hours to minimize impact on production workloads.</p>
                            } else if schema.TaskName == "erasure_coding" {
                                <h6 class="alert-heading">Erasure Coding Operations:</h6>
                                <p class="mb-2"><strong>Performance:</strong> Erasure coding is CPU and I/O intensive. Consider running during off-peak hours.</p>
                                <p class="mb-2"><strong>Durability:</strong> With 10+4 configuration, can tolerate up to 4 shard failures.</p>
                                <p class="mb-0"><strong>Configuration:</strong> Fullness ratio should be between 0.5 and 1.0 (e.g., 0.90 for 90%).</p>
                            }
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>

    <script>
        function resetToDefaults() {
            if (confirm('Are you sure you want to reset to default configuration? This will overwrite your current settings.')) {
                // Reset form fields to their default values
                const form = document.getElementById('taskConfigForm');
                const schemaFields = window.taskConfigSchema ? window.taskConfigSchema.fields : {};
                
                Object.keys(schemaFields).forEach(fieldName => {
                    const field = schemaFields[fieldName];
                    const element = document.getElementById(fieldName);
                    
                    if (element && field.default_value !== undefined) {
                        if (field.input_type === 'checkbox') {
                            element.checked = field.default_value;
                        } else if (field.input_type === 'interval') {
                            // Handle interval fields with value and unit
                            const valueElement = document.getElementById(fieldName + '_value');
                            const unitElement = document.getElementById(fieldName + '_unit');
                            if (valueElement && unitElement && field.default_value) {
                                const defaultSeconds = field.default_value;
                                const { value, unit } = convertSecondsToTaskIntervalValueUnit(defaultSeconds);
                                valueElement.value = value;
                                unitElement.value = unit;
                            }
                        } else {
                            element.value = field.default_value;
                        }
                    }
                });
            }
        }

        function convertSecondsToTaskIntervalValueUnit(totalSeconds) {
            if (totalSeconds === 0) {
                return { value: 0, unit: 'minutes' };
            }

            // Check if it's evenly divisible by days
            if (totalSeconds % (24 * 3600) === 0) {
                return { value: totalSeconds / (24 * 3600), unit: 'days' };
            }

            // Check if it's evenly divisible by hours
            if (totalSeconds % 3600 === 0) {
                return { value: totalSeconds / 3600, unit: 'hours' };
            }

            // Default to minutes
            return { value: totalSeconds / 60, unit: 'minutes' };
        }

        // Store schema data for JavaScript access (moved to after div is created)
    </script>
    
    <!-- Hidden element to store schema data -->
    <div data-task-schema={ taskSchemaToBase64JSON(schema) } style="display: none;"></div>
    
    <script>
        // Load schema data now that the div exists
        const base64Data = document.querySelector('[data-task-schema]').getAttribute('data-task-schema');
        const jsonStr = atob(base64Data);
        window.taskConfigSchema = JSON.parse(jsonStr);
    </script>
}

// TaskConfigField renders a single task configuration field based on schema with typed field lookup
templ TaskConfigField(field *config.Field, config interface{}) {
    if field.InputType == "interval" {
        <!-- Interval field with number input + unit dropdown -->
        <div class="mb-3">
            <label for={ field.JSONName } class="form-label">
                { field.DisplayName }
                if field.Required {
                    <span class="text-danger">*</span>
                }
            </label>
            <div class="input-group">
                <input 
                    type="number" 
                    class="form-control" 
                    id={ field.JSONName + "_value" } 
                    name={ field.JSONName + "_value" } 
                    value={ fmt.Sprintf("%.0f", components.ConvertInt32SecondsToDisplayValue(getTaskConfigInt32Field(config, field.JSONName))) }
                    step="1"
                    min="1"
                    if field.Required {
                        required
                    }
                />
                <select 
                    class="form-select" 
                    id={ field.JSONName + "_unit" } 
                    name={ field.JSONName + "_unit" }
                    style="max-width: 120px;"
                    if field.Required {
                        required
                    }
                >
                    <option 
                        value="minutes"
                        if components.GetInt32DisplayUnit(getTaskConfigInt32Field(config, field.JSONName)) == "minutes" {
                            selected
                        }
                    >
                        Minutes
                    </option>
                    <option 
                        value="hours"
                        if components.GetInt32DisplayUnit(getTaskConfigInt32Field(config, field.JSONName)) == "hours" {
                            selected
                        }
                    >
                        Hours
                    </option>
                    <option 
                        value="days"
                        if components.GetInt32DisplayUnit(getTaskConfigInt32Field(config, field.JSONName)) == "days" {
                            selected
                        }
                    >
                        Days
                    </option>
                </select>
            </div>
            if field.Description != "" {
                <div class="form-text text-muted">{ field.Description }</div>
            }
        </div>
    } else if field.InputType == "checkbox" {
        <!-- Checkbox field -->
        <div class="mb-3">
            <div class="form-check form-switch">
                                        <input 
                    class="form-check-input"
                    type="checkbox" 
                    id={ field.JSONName }
                    name={ field.JSONName }
                    value="on"
                    if getTaskConfigBoolField(config, field.JSONName) {
                        checked
                    }
                />
                <label class="form-check-label" for={ field.JSONName }>
                    <strong>{ field.DisplayName }</strong>
                </label>
            </div>
            if field.Description != "" {
                <div class="form-text text-muted">{ field.Description }</div>
            }
        </div>
    } else if field.InputType == "text" {
        <!-- Text field -->
        <div class="mb-3">
            <label for={ field.JSONName } class="form-label">
                { field.DisplayName }
                if field.Required {
                    <span class="text-danger">*</span>
                }
            </label>
            <input 
                type="text" 
                class="form-control" 
                id={ field.JSONName }
                name={ field.JSONName }
                value={ getTaskConfigStringField(config, field.JSONName) }
                placeholder={ field.Placeholder }
                if field.Required {
                    required
                }
            />
            if field.Description != "" {
                <div class="form-text text-muted">{ field.Description }</div>
            }
        </div>
    } else {
        <!-- Number field -->
        <div class="mb-3">
            <label for={ field.JSONName } class="form-label">
                { field.DisplayName }
                if field.Required {
                    <span class="text-danger">*</span>
                }
            </label>
            <input 
                type="number" 
                class="form-control" 
                id={ field.JSONName }
                name={ field.JSONName }
                value={ fmt.Sprintf("%.6g", getTaskConfigFloatField(config, field.JSONName)) }
                placeholder={ field.Placeholder }
                if field.MinValue != nil {
                    min={ fmt.Sprintf("%v", field.MinValue) }
                }
                if field.MaxValue != nil {
                    max={ fmt.Sprintf("%v", field.MaxValue) }
                }
                step={ getTaskNumberStep(field) }
                if field.Required {
                    required
                }
            />
            if field.Description != "" {
                <div class="form-text text-muted">{ field.Description }</div>
            }
        </div>
    }
}

// Typed field getters for task configs - avoiding interface{} where possible
func getTaskConfigBoolField(config interface{}, fieldName string) bool {
    switch fieldName {
    case "enabled":
        // Use reflection only for the common 'enabled' field in BaseConfig
        if value := getTaskFieldValue(config, fieldName); value != nil {
            if boolVal, ok := value.(bool); ok {
                return boolVal
            }
        }
        return false
    default:
        // For other boolean fields, use reflection
        if value := getTaskFieldValue(config, fieldName); value != nil {
            if boolVal, ok := value.(bool); ok {
                return boolVal
            }
        }
        return false
    }
}

func getTaskConfigInt32Field(config interface{}, fieldName string) int32 {
    switch fieldName {
    case "scan_interval_seconds", "max_concurrent":
        // Common fields that should be int/int32
        if value := getTaskFieldValue(config, fieldName); value != nil {
            switch v := value.(type) {
            case int32:
                return v
            case int:
                return int32(v)
            case int64:
                return int32(v)
            }
        }
        return 0
    default:
        // For other int fields, use reflection
        if value := getTaskFieldValue(config, fieldName); value != nil {
            switch v := value.(type) {
            case int32:
                return v
            case int:
                return int32(v)
            case int64:
                return int32(v)
            case float64:
                return int32(v)
            }
        }
        return 0
    }
}

func getTaskConfigFloatField(config interface{}, fieldName string) float64 {
    if value := getTaskFieldValue(config, fieldName); value != nil {
        switch v := value.(type) {
        case float64:
            return v
        case float32:
            return float64(v)
        case int:
            return float64(v)
        case int32:
            return float64(v)
        case int64:
            return float64(v)
        }
    }
    return 0.0
}

func getTaskConfigStringField(config interface{}, fieldName string) string {
    if value := getTaskFieldValue(config, fieldName); value != nil {
        if strVal, ok := value.(string); ok {
            return strVal
        }
        // Convert numbers to strings for form display
        switch v := value.(type) {
        case int:
            return fmt.Sprintf("%d", v)
        case int32:
            return fmt.Sprintf("%d", v)
        case int64:
            return fmt.Sprintf("%d", v)
        case float64:
            return fmt.Sprintf("%.6g", v)
        case float32:
            return fmt.Sprintf("%.6g", v)
        }
    }
    return ""
}

func getTaskNumberStep(field *config.Field) string {
    if field.Type == config.FieldTypeFloat {
        return "0.01"
    }
    return "1"
}

func getTaskFieldValue(config interface{}, fieldName string) interface{} {
    if config == nil {
        return nil
    }
    
    // Use reflection to get the field value from the config struct
    configValue := reflect.ValueOf(config)
    if configValue.Kind() == reflect.Ptr {
        configValue = configValue.Elem()
    }
    
    if configValue.Kind() != reflect.Struct {
        return nil
    }
    
    configType := configValue.Type()
    
    for i := 0; i < configValue.NumField(); i++ {
        field := configValue.Field(i)
        fieldType := configType.Field(i)
        
        // Handle embedded structs recursively (before JSON tag check)
        if field.Kind() == reflect.Struct && fieldType.Anonymous {
            if value := getTaskFieldValue(field.Interface(), fieldName); value != nil {
                return value
            }
            continue
        }
        
        // Get JSON tag name
        jsonTag := fieldType.Tag.Get("json")
        if jsonTag == "" {
            continue
        }
        
        // Remove options like ",omitempty"
        if commaIdx := strings.Index(jsonTag, ","); commaIdx > 0 {
            jsonTag = jsonTag[:commaIdx]
        }
        
        // Check if this is the field we're looking for
        if jsonTag == fieldName {
            return field.Interface()
        }
    }
    
    return nil
}