package training

import (
	"time"

	"github.com/google/uuid"
)

// ============================================================================
// Constants / Enums
// ============================================================================

// RegulationArea represents a compliance regulation area
type RegulationArea string

const (
	RegulationDSGVO    RegulationArea = "dsgvo"
	RegulationNIS2     RegulationArea = "nis2"
	RegulationISO27001 RegulationArea = "iso27001"
	RegulationAIAct    RegulationArea = "ai_act"
	RegulationGeschGehG RegulationArea = "geschgehg"
	RegulationHinSchG  RegulationArea = "hinschg"
)

// FrequencyType represents the training frequency
type FrequencyType string

const (
	FrequencyOnboarding   FrequencyType = "onboarding"
	FrequencyAnnual       FrequencyType = "annual"
	FrequencyEventTrigger FrequencyType = "event_trigger"
	FrequencyMicro        FrequencyType = "micro"
)

// AssignmentStatus represents the status of a training assignment
type AssignmentStatus string

const (
	AssignmentStatusPending    AssignmentStatus = "pending"
	AssignmentStatusInProgress AssignmentStatus = "in_progress"
	AssignmentStatusCompleted  AssignmentStatus = "completed"
	AssignmentStatusOverdue    AssignmentStatus = "overdue"
	AssignmentStatusExpired    AssignmentStatus = "expired"
)

// TriggerType represents how a training was assigned
type TriggerType string

const (
	TriggerOnboarding TriggerType = "onboarding"
	TriggerAnnual     TriggerType = "annual"
	TriggerEvent      TriggerType = "event"
	TriggerManual     TriggerType = "manual"
)

// ContentFormat represents the format of module content
type ContentFormat string

const (
	ContentFormatMarkdown ContentFormat = "markdown"
	ContentFormatHTML     ContentFormat = "html"
)

// Difficulty represents the difficulty level of a quiz question
type Difficulty string

const (
	DifficultyEasy   Difficulty = "easy"
	DifficultyMedium Difficulty = "medium"
	DifficultyHard   Difficulty = "hard"
)

// AuditAction represents an action in the audit trail
type AuditAction string

const (
	AuditActionAssigned         AuditAction = "assigned"
	AuditActionStarted          AuditAction = "started"
	AuditActionCompleted        AuditAction = "completed"
	AuditActionQuizSubmitted    AuditAction = "quiz_submitted"
	AuditActionEscalated        AuditAction = "escalated"
	AuditActionCertificateIssued AuditAction = "certificate_issued"
	AuditActionContentGenerated AuditAction = "content_generated"
)

// AuditEntityType represents the type of entity in audit log
type AuditEntityType string

const (
	AuditEntityAssignment  AuditEntityType = "assignment"
	AuditEntityModule      AuditEntityType = "module"
	AuditEntityQuiz        AuditEntityType = "quiz"
	AuditEntityCertificate AuditEntityType = "certificate"
)

// ============================================================================
// Role Constants
// ============================================================================

const (
	RoleR1 = "R1" // Geschaeftsfuehrung
	RoleR2 = "R2" // IT-Leitung
	RoleR3 = "R3" // DSB
	RoleR4 = "R4" // ISB
	RoleR5 = "R5" // HR
	RoleR6 = "R6" // Einkauf
	RoleR7 = "R7" // Fachabteilung
	RoleR8 = "R8" // IT-Admin
	RoleR9 = "R9" // Alle Mitarbeiter
)

// RoleLabels maps role codes to human-readable labels
var RoleLabels = map[string]string{
	RoleR1: "Geschaeftsfuehrung",
	RoleR2: "IT-Leitung",
	RoleR3: "Datenschutzbeauftragter",
	RoleR4: "Informationssicherheitsbeauftragter",
	RoleR5: "HR / Personal",
	RoleR6: "Einkauf / Beschaffung",
	RoleR7: "Fachabteilung",
	RoleR8: "IT-Administration",
	RoleR9: "Alle Mitarbeiter",
}

// NIS2RoleMapping maps internal roles to NIS2 levels
var NIS2RoleMapping = map[string]string{
	RoleR1: "N1", // Geschaeftsfuehrung
	RoleR2: "N2", // IT-Leitung
	RoleR3: "N3", // DSB
	RoleR4: "N3", // ISB
	RoleR5: "N4", // HR
	RoleR6: "N4", // Einkauf
	RoleR7: "N5", // Fachabteilung
	RoleR8: "N2", // IT-Admin
	RoleR9: "N5", // Alle Mitarbeiter
}

// ============================================================================
// Main Entities
// ============================================================================

// TrainingModule represents a compliance training module
type TrainingModule struct {
	ID              uuid.UUID      `json:"id"`
	TenantID        uuid.UUID      `json:"tenant_id"`
	AcademyCourseID *uuid.UUID     `json:"academy_course_id,omitempty"`
	ModuleCode      string         `json:"module_code"`
	Title           string         `json:"title"`
	Description     string         `json:"description,omitempty"`
	RegulationArea  RegulationArea `json:"regulation_area"`
	NIS2Relevant    bool           `json:"nis2_relevant"`
	ISOControls     []string       `json:"iso_controls"`       // JSONB
	FrequencyType   FrequencyType  `json:"frequency_type"`
	ValidityDays    int            `json:"validity_days"`
	RiskWeight      float64        `json:"risk_weight"`
	ContentType     string         `json:"content_type"`
	DurationMinutes int            `json:"duration_minutes"`
	PassThreshold   int            `json:"pass_threshold"`
	IsActive        bool           `json:"is_active"`
	SortOrder       int            `json:"sort_order"`
	CreatedAt       time.Time      `json:"created_at"`
	UpdatedAt       time.Time      `json:"updated_at"`
}

// TrainingMatrixEntry represents a role-to-module mapping in the CTM
type TrainingMatrixEntry struct {
	ID          uuid.UUID `json:"id"`
	TenantID    uuid.UUID `json:"tenant_id"`
	RoleCode    string    `json:"role_code"`
	ModuleID    uuid.UUID `json:"module_id"`
	IsMandatory bool      `json:"is_mandatory"`
	Priority    int       `json:"priority"`
	CreatedAt   time.Time `json:"created_at"`
	// Joined fields (optional, populated in queries)
	ModuleCode  string    `json:"module_code,omitempty"`
	ModuleTitle string    `json:"module_title,omitempty"`
}

// TrainingAssignment represents a user's training assignment
type TrainingAssignment struct {
	ID               uuid.UUID        `json:"id"`
	TenantID         uuid.UUID        `json:"tenant_id"`
	ModuleID         uuid.UUID        `json:"module_id"`
	UserID           uuid.UUID        `json:"user_id"`
	UserName         string           `json:"user_name"`
	UserEmail        string           `json:"user_email"`
	RoleCode         string           `json:"role_code,omitempty"`
	TriggerType      TriggerType      `json:"trigger_type"`
	TriggerEvent     string           `json:"trigger_event,omitempty"`
	Status           AssignmentStatus `json:"status"`
	ProgressPercent  int              `json:"progress_percent"`
	QuizScore        *float64         `json:"quiz_score,omitempty"`
	QuizPassed       *bool            `json:"quiz_passed,omitempty"`
	QuizAttempts     int              `json:"quiz_attempts"`
	StartedAt        *time.Time       `json:"started_at,omitempty"`
	CompletedAt      *time.Time       `json:"completed_at,omitempty"`
	Deadline         time.Time        `json:"deadline"`
	CertificateID   *uuid.UUID       `json:"certificate_id,omitempty"`
	EscalationLevel  int              `json:"escalation_level"`
	LastEscalationAt *time.Time       `json:"last_escalation_at,omitempty"`
	EnrollmentID     *uuid.UUID       `json:"enrollment_id,omitempty"`
	CreatedAt        time.Time        `json:"created_at"`
	UpdatedAt        time.Time        `json:"updated_at"`
	// Joined fields
	ModuleCode       string           `json:"module_code,omitempty"`
	ModuleTitle      string           `json:"module_title,omitempty"`
}

// QuizQuestion represents a persistent quiz question for a module
type QuizQuestion struct {
	ID           uuid.UUID  `json:"id"`
	ModuleID     uuid.UUID  `json:"module_id"`
	Question     string     `json:"question"`
	Options      []string   `json:"options"`        // JSONB
	CorrectIndex int        `json:"correct_index"`
	Explanation  string     `json:"explanation,omitempty"`
	Difficulty   Difficulty `json:"difficulty"`
	IsActive     bool       `json:"is_active"`
	SortOrder    int        `json:"sort_order"`
	CreatedAt    time.Time  `json:"created_at"`
}

// QuizAttempt represents a single quiz attempt by a user
type QuizAttempt struct {
	ID              uuid.UUID    `json:"id"`
	AssignmentID    uuid.UUID    `json:"assignment_id"`
	UserID          uuid.UUID    `json:"user_id"`
	Answers         []QuizAnswer `json:"answers"`       // JSONB
	Score           float64      `json:"score"`
	Passed          bool         `json:"passed"`
	CorrectCount    int          `json:"correct_count"`
	TotalCount      int          `json:"total_count"`
	DurationSeconds *int         `json:"duration_seconds,omitempty"`
	AttemptedAt     time.Time    `json:"attempted_at"`
}

// QuizAnswer represents a single answer within a quiz attempt
type QuizAnswer struct {
	QuestionID    uuid.UUID `json:"question_id"`
	SelectedIndex int       `json:"selected_index"`
	Correct       bool      `json:"correct"`
}

// AuditLogEntry represents an entry in the training audit trail
type AuditLogEntry struct {
	ID         uuid.UUID       `json:"id"`
	TenantID   uuid.UUID       `json:"tenant_id"`
	UserID     *uuid.UUID      `json:"user_id,omitempty"`
	Action     AuditAction     `json:"action"`
	EntityType AuditEntityType `json:"entity_type"`
	EntityID   *uuid.UUID      `json:"entity_id,omitempty"`
	Details    map[string]interface{} `json:"details"`  // JSONB
	IPAddress  string          `json:"ip_address,omitempty"`
	CreatedAt  time.Time       `json:"created_at"`
}

// ModuleContent represents LLM-generated or manual content for a module
type ModuleContent struct {
	ID            uuid.UUID     `json:"id"`
	ModuleID      uuid.UUID     `json:"module_id"`
	Version       int           `json:"version"`
	ContentFormat ContentFormat `json:"content_format"`
	ContentBody   string        `json:"content_body"`
	Summary       string        `json:"summary,omitempty"`
	GeneratedBy   string        `json:"generated_by,omitempty"`
	LLMModel      string        `json:"llm_model,omitempty"`
	IsPublished   bool          `json:"is_published"`
	ReviewedBy    *uuid.UUID    `json:"reviewed_by,omitempty"`
	ReviewedAt    *time.Time    `json:"reviewed_at,omitempty"`
	CreatedAt     time.Time     `json:"created_at"`
	UpdatedAt     time.Time     `json:"updated_at"`
}

// TrainingStats contains aggregated training metrics
type TrainingStats struct {
	TotalModules      int     `json:"total_modules"`
	TotalAssignments  int     `json:"total_assignments"`
	CompletionRate    float64 `json:"completion_rate"`
	OverdueCount      int     `json:"overdue_count"`
	PendingCount      int     `json:"pending_count"`
	InProgressCount   int     `json:"in_progress_count"`
	CompletedCount    int     `json:"completed_count"`
	AvgQuizScore      float64 `json:"avg_quiz_score"`
	AvgCompletionDays float64 `json:"avg_completion_days"`
	UpcomingDeadlines int     `json:"upcoming_deadlines"` // within 7 days
}

// ComplianceGap represents a missing or overdue training requirement
type ComplianceGap struct {
	ModuleID       uuid.UUID      `json:"module_id"`
	ModuleCode     string         `json:"module_code"`
	ModuleTitle    string         `json:"module_title"`
	RegulationArea RegulationArea `json:"regulation_area"`
	RoleCode       string         `json:"role_code"`
	IsMandatory    bool           `json:"is_mandatory"`
	AssignmentID   *uuid.UUID     `json:"assignment_id,omitempty"`
	Status         string         `json:"status"`  // "missing", "overdue", "expired"
	Deadline       *time.Time     `json:"deadline,omitempty"`
}

// EscalationResult represents the result of an escalation check
type EscalationResult struct {
	AssignmentID    uuid.UUID `json:"assignment_id"`
	UserID          uuid.UUID `json:"user_id"`
	UserName        string    `json:"user_name"`
	UserEmail       string    `json:"user_email"`
	ModuleTitle     string    `json:"module_title"`
	PreviousLevel   int       `json:"previous_level"`
	NewLevel        int       `json:"new_level"`
	DaysOverdue     int       `json:"days_overdue"`
	EscalationLabel string    `json:"escalation_label"`
}

// DeadlineInfo represents upcoming deadline information
type DeadlineInfo struct {
	AssignmentID uuid.UUID `json:"assignment_id"`
	ModuleCode   string    `json:"module_code"`
	ModuleTitle  string    `json:"module_title"`
	UserID       uuid.UUID `json:"user_id"`
	UserName     string    `json:"user_name"`
	Deadline     time.Time `json:"deadline"`
	DaysLeft     int       `json:"days_left"`
	Status       AssignmentStatus `json:"status"`
}

// ============================================================================
// Filter Types
// ============================================================================

// ModuleFilters defines filters for listing modules
type ModuleFilters struct {
	RegulationArea RegulationArea
	FrequencyType  FrequencyType
	IsActive       *bool
	NIS2Relevant   *bool
	Search         string
	Limit          int
	Offset         int
}

// AssignmentFilters defines filters for listing assignments
type AssignmentFilters struct {
	ModuleID  *uuid.UUID
	UserID    *uuid.UUID
	RoleCode  string
	Status    AssignmentStatus
	Overdue   *bool
	Limit     int
	Offset    int
}

// AuditLogFilters defines filters for listing audit log entries
type AuditLogFilters struct {
	UserID     *uuid.UUID
	Action     AuditAction
	EntityType AuditEntityType
	Limit      int
	Offset     int
}

// ============================================================================
// API Request/Response Types
// ============================================================================

// CreateModuleRequest is the API request for creating a training module
type CreateModuleRequest struct {
	ModuleCode      string         `json:"module_code" binding:"required"`
	Title           string         `json:"title" binding:"required"`
	Description     string         `json:"description,omitempty"`
	RegulationArea  RegulationArea `json:"regulation_area" binding:"required"`
	NIS2Relevant    bool           `json:"nis2_relevant"`
	ISOControls     []string       `json:"iso_controls,omitempty"`
	FrequencyType   FrequencyType  `json:"frequency_type" binding:"required"`
	ValidityDays    int            `json:"validity_days"`
	RiskWeight      float64        `json:"risk_weight"`
	ContentType     string         `json:"content_type"`
	DurationMinutes int            `json:"duration_minutes"`
	PassThreshold   int            `json:"pass_threshold"`
}

// UpdateModuleRequest is the API request for updating a training module
type UpdateModuleRequest struct {
	Title           *string         `json:"title,omitempty"`
	Description     *string         `json:"description,omitempty"`
	NIS2Relevant    *bool           `json:"nis2_relevant,omitempty"`
	ISOControls     []string        `json:"iso_controls,omitempty"`
	ValidityDays    *int            `json:"validity_days,omitempty"`
	RiskWeight      *float64        `json:"risk_weight,omitempty"`
	DurationMinutes *int            `json:"duration_minutes,omitempty"`
	PassThreshold   *int            `json:"pass_threshold,omitempty"`
	IsActive        *bool           `json:"is_active,omitempty"`
}

// SetMatrixEntryRequest is the API request for setting a CTM entry
type SetMatrixEntryRequest struct {
	RoleCode    string    `json:"role_code" binding:"required"`
	ModuleID    uuid.UUID `json:"module_id" binding:"required"`
	IsMandatory bool      `json:"is_mandatory"`
	Priority    int       `json:"priority"`
}

// ComputeAssignmentsRequest is the API request for computing assignments
type ComputeAssignmentsRequest struct {
	UserID    uuid.UUID `json:"user_id" binding:"required"`
	UserName  string    `json:"user_name" binding:"required"`
	UserEmail string    `json:"user_email" binding:"required"`
	Roles     []string  `json:"roles" binding:"required"`
	Trigger   string    `json:"trigger"`
}

// UpdateAssignmentProgressRequest updates progress on an assignment
type UpdateAssignmentProgressRequest struct {
	Progress int `json:"progress" binding:"required"`
}

// SubmitTrainingQuizRequest is the API request for submitting a quiz
type SubmitTrainingQuizRequest struct {
	AssignmentID    uuid.UUID    `json:"assignment_id" binding:"required"`
	Answers         []QuizAnswer `json:"answers" binding:"required"`
	DurationSeconds *int         `json:"duration_seconds,omitempty"`
}

// SubmitTrainingQuizResponse is the API response for quiz submission
type SubmitTrainingQuizResponse struct {
	AttemptID    uuid.UUID `json:"attempt_id"`
	Score        float64   `json:"score"`
	Passed       bool      `json:"passed"`
	CorrectCount int       `json:"correct_count"`
	TotalCount   int       `json:"total_count"`
	Threshold    int       `json:"threshold"`
}

// GenerateContentRequest is the API request for LLM content generation
type GenerateContentRequest struct {
	ModuleID uuid.UUID `json:"module_id" binding:"required"`
	Language string    `json:"language"`
}

// GenerateQuizRequest is the API request for LLM quiz generation
type GenerateQuizRequest struct {
	ModuleID uuid.UUID `json:"module_id" binding:"required"`
	Count    int       `json:"count"`
}

// PublishContentRequest is the API request for publishing content
type PublishContentRequest struct {
	ReviewedBy uuid.UUID `json:"reviewed_by"`
}

// BulkAssignRequest is the API request for bulk assigning a module
type BulkAssignRequest struct {
	ModuleID  uuid.UUID `json:"module_id" binding:"required"`
	RoleCodes []string  `json:"role_codes" binding:"required"`
	Trigger   string    `json:"trigger"`
	Deadline  time.Time `json:"deadline" binding:"required"`
}

// ModuleListResponse is the API response for listing modules
type ModuleListResponse struct {
	Modules []TrainingModule `json:"modules"`
	Total   int              `json:"total"`
}

// AssignmentListResponse is the API response for listing assignments
type AssignmentListResponse struct {
	Assignments []TrainingAssignment `json:"assignments"`
	Total       int                  `json:"total"`
}

// MatrixResponse is the API response for the full training matrix
type MatrixResponse struct {
	Entries map[string][]TrainingMatrixEntry `json:"entries"` // role_code -> entries
	Roles   map[string]string               `json:"roles"`   // role_code -> label
}

// AuditLogResponse is the API response for listing audit log entries
type AuditLogResponse struct {
	Entries []AuditLogEntry `json:"entries"`
	Total   int             `json:"total"`
}

// EscalationResponse is the API response for escalation check
type EscalationResponse struct {
	Results     []EscalationResult `json:"results"`
	TotalChecked int               `json:"total_checked"`
	Escalated    int               `json:"escalated"`
}

// DeadlineListResponse is the API response for listing deadlines
type DeadlineListResponse struct {
	Deadlines []DeadlineInfo `json:"deadlines"`
	Total     int            `json:"total"`
}

// BulkResult holds the result of a bulk generation operation
type BulkResult struct {
	Generated int      `json:"generated"`
	Skipped   int      `json:"skipped"`
	Errors    []string `json:"errors"`
}