package inspector

import (
	"fmt"
	"time"

	"git.warky.dev/wdevs/relspecgo/pkg/models"
)

// Inspector performs validation on database models
type Inspector struct {
	config *Config
	db     *models.Database
}

// ValidationResult represents the result of a single validation check
type ValidationResult struct {
	RuleName string                 `json:"rule_name"`
	Level    string                 `json:"level"` // "error" or "warning"
	Message  string                 `json:"message"`
	Location string                 `json:"location"` // e.g., "schema.table.column"
	Context  map[string]interface{} `json:"context"`
	Passed   bool                   `json:"passed"`
}

// InspectorReport contains the complete validation report
type InspectorReport struct {
	Summary      ReportSummary      `json:"summary"`
	Violations   []ValidationResult `json:"violations"`
	GeneratedAt  time.Time          `json:"generated_at"`
	Database     string             `json:"database"`
	SourceFormat string             `json:"source_format"`
}

// ReportSummary contains aggregate statistics
type ReportSummary struct {
	TotalRules   int `json:"total_rules"`
	RulesChecked int `json:"rules_checked"`
	RulesSkipped int `json:"rules_skipped"`
	ErrorCount   int `json:"error_count"`
	WarningCount int `json:"warning_count"`
	PassedCount  int `json:"passed_count"`
}

// NewInspector creates a new inspector with the given database and configuration
func NewInspector(db *models.Database, config *Config) *Inspector {
	return &Inspector{
		config: config,
		db:     db,
	}
}

// Inspect runs all enabled validation rules and returns a report
func (i *Inspector) Inspect() (*InspectorReport, error) {
	results := []ValidationResult{}

	// Run all enabled validators
	for ruleName, rule := range i.config.Rules {
		if !rule.IsEnabled() {
			continue
		}

		// Get the validator function for this rule using the function field
		validator, exists := getValidator(rule.Function)
		if !exists {
			// Skip unknown validator functions
			continue
		}

		// Run the validator
		ruleResults := validator(i.db, rule, ruleName)

		// Set the level based on rule configuration
		level := "warning"
		if rule.IsEnforced() {
			level = "error"
		}

		for idx := range ruleResults {
			ruleResults[idx].Level = level
		}

		results = append(results, ruleResults...)
	}

	// Generate summary
	summary := i.generateSummary(results)

	report := &InspectorReport{
		Summary:      summary,
		Violations:   results,
		GeneratedAt:  time.Now(),
		Database:     i.db.Name,
		SourceFormat: i.db.SourceFormat,
	}

	return report, nil
}

// generateSummary creates summary statistics from validation results
func (i *Inspector) generateSummary(results []ValidationResult) ReportSummary {
	summary := ReportSummary{
		TotalRules: len(i.config.Rules),
	}

	// Count enabled rules
	for _, rule := range i.config.Rules {
		if rule.IsEnabled() {
			summary.RulesChecked++
		} else {
			summary.RulesSkipped++
		}
	}

	// Count violations by level
	for _, result := range results {
		if result.Passed {
			summary.PassedCount++
		} else {
			if result.Level == "error" {
				summary.ErrorCount++
			} else {
				summary.WarningCount++
			}
		}
	}

	return summary
}

// HasErrors returns true if the report contains any errors
func (r *InspectorReport) HasErrors() bool {
	return r.Summary.ErrorCount > 0
}

// validatorFunc is a function that validates a rule against a database
type validatorFunc func(*models.Database, Rule, string) []ValidationResult

// getValidator returns the validator function for a given function name
func getValidator(functionName string) (validatorFunc, bool) {
	validators := map[string]validatorFunc{
		"primary_key_naming":            validatePrimaryKeyNaming,
		"primary_key_datatype":          validatePrimaryKeyDatatype,
		"primary_key_auto_increment":    validatePrimaryKeyAutoIncrement,
		"foreign_key_column_naming":     validateForeignKeyColumnNaming,
		"foreign_key_constraint_naming": validateForeignKeyConstraintNaming,
		"foreign_key_index":             validateForeignKeyIndex,
		"table_regexpr":                 validateTableNamingCase,
		"column_regexpr":                validateColumnNamingCase,
		"table_name_length":             validateTableNameLength,
		"column_name_length":            validateColumnNameLength,
		"reserved_words":                validateReservedKeywords,
		"have_primary_key":              validateMissingPrimaryKey,
		"orphaned_foreign_key":          validateOrphanedForeignKey,
		"circular_dependency":           validateCircularDependency,
	}

	fn, exists := validators[functionName]
	return fn, exists
}

// createResult is a helper to create a validation result
func createResult(ruleName string, passed bool, message string, location string, context map[string]interface{}) ValidationResult {
	return ValidationResult{
		RuleName: ruleName,
		Message:  message,
		Location: location,
		Context:  context,
		Passed:   passed,
	}
}

// formatLocation creates a location string from schema, table, and optional column
func formatLocation(schema, table, column string) string {
	if column != "" {
		return fmt.Sprintf("%s.%s.%s", schema, table, column)
	}
	if table != "" {
		return fmt.Sprintf("%s.%s", schema, table)
	}
	return schema
}