SerpentRace/SerpentRace_Backend/src/Application/Game/BoardGenerationService.ts

import { GameField, BoardData } from '../../Domain/Game/GameAggregate';
import { logOther, logError } from '../Services/Logger';

interface SpecialFieldInfo {
    position: number;
    type: 'positive' | 'negative' | 'luck';
}

export class BoardGenerationService {
    async generateBoard(
        positiveFieldCount: number,
        negativeFieldCount: number,
        luckFieldCount: number
    ): Promise<BoardData> {
        // Pattern-based approach has 100% success rate, no retry needed
        const result = this.generateSingleAttempt(positiveFieldCount, negativeFieldCount, luckFieldCount);
        
        logOther('Pattern-based board generation completed', {
            totalFields: result.fields.length,
            specialFields: result.fields.filter((f: GameField) => f.type !== 'regular').length,
            positiveFields: result.fields.filter((f: GameField) => f.type === 'positive').length,
            negativeFields: result.fields.filter((f: GameField) => f.type === 'negative').length,
            luckFields: result.fields.filter((f: GameField) => f.type === 'luck').length
        });

        return result;
    }

    private generateSingleAttempt(
        positiveFieldCount: number,
        negativeFieldCount: number,
        luckFieldCount: number
    ): BoardData {
        // Step 1: Choose special field positions
        const specialFieldPositions = this.chooseSpecialFieldPositions(
            positiveFieldCount,
            negativeFieldCount,
            luckFieldCount
        );

        // Step 2: Calculate step values using pattern-based approach
        const fields = this.calculatePatternBasedStepValues(specialFieldPositions);

        return {
            fields
        };
    }

    private chooseSpecialFieldPositions(
        positiveFieldCount: number,
        negativeFieldCount: number,
        luckFieldCount: number
    ): SpecialFieldInfo[] {
        const totalSpecial = positiveFieldCount + negativeFieldCount + luckFieldCount;
        const specialFields: SpecialFieldInfo[] = [];

        // Generate unique random positions
        const positions = new Set<number>();
        while (positions.size < totalSpecial) {
            const position = Math.floor(Math.random() * 100) + 1; // 1-100
            positions.add(position);
        }

        // Convert to sorted array
        const sortedPositions = Array.from(positions).sort((a, b) => a - b);
        
        // Distribute types randomly
        const types: ('positive' | 'negative' | 'luck')[] = [
            ...Array(positiveFieldCount).fill('positive'),
            ...Array(negativeFieldCount).fill('negative'),
            ...Array(luckFieldCount).fill('luck')
        ];
        
        // Shuffle types
        for (let i = types.length - 1; i > 0; i--) {
            const j = Math.floor(Math.random() * (i + 1));
            [types[i], types[j]] = [types[j], types[i]];
        }

        sortedPositions.forEach((position, index) => {
            specialFields.push({
                position,
                type: types[index] || 'positive'
            });
        });

        return specialFields;
    }

    private calculatePatternBasedStepValues(specialFields: SpecialFieldInfo[]): GameField[] {
        // Initialize all fields as regular
        const fields: GameField[] = Array.from({ length: 100 }, (_, i) => ({
            position: i + 1,
            type: 'regular' as const
        }));

        // Update special fields with pattern-based step values
        specialFields.forEach(specialField => {
            const fieldIndex = specialField.position - 1; // Convert to 0-based index
            fields[fieldIndex].type = specialField.type;

            if (specialField.type === 'luck') {
                // Luck fields don't need step values
                return;
            }

            // Calculate step values based on position rules
            let maxStepValue: number;
            let minStepValue: number;

            if (specialField.position <= 80) {
                // Positions 1-80: step values can be ±20
                maxStepValue = 20;
                minStepValue = -20;
            } else {
                // Positions 81-100: step values can be -30 to +10
                maxStepValue = 10;
                minStepValue = -30;
            }

            // Generate appropriate step value for field type
            if (specialField.type === 'positive') {
                // Positive fields: use positive step values (3-8 range for good gameplay)
                const stepValue = Math.floor(Math.random() * 6) + 3; // 3-8
                fields[fieldIndex].stepValue = Math.min(stepValue, maxStepValue);
            } else {
                // Negative fields: use negative step values (-3 to -8 range)
                const stepValue = -(Math.floor(Math.random() * 6) + 3); // -3 to -8
                fields[fieldIndex].stepValue = Math.max(stepValue, minStepValue);
            }
        });

        return fields;
    }

    // This method can be used by FieldEffectService for movement calculations
    public calculatePatternBasedMovement(
        currentPosition: number,
        stepValue: number,
        diceValue: number
    ): number {
        // Calculate pattern modifier based on current position
        const patternModifier = this.getPatternModifier(currentPosition);
        
        // Calculate final position: currentPosition + (stepValue × dice) + patternModifier
        const movement = stepValue * diceValue;
        let finalPosition = currentPosition + movement + patternModifier;
        
        // Ensure position stays within board bounds (1-100)
        if (finalPosition < 1) {
            finalPosition = 1;
        } else if (finalPosition > 100) {
            finalPosition = 100;
        }
        
        return finalPosition;
    }

    private getPatternModifier(position: number): number {
        // Pattern modifiers for strategic complexity:
        // - Positions ending in 0 (10, 20, 30...): No modifier
        // - Positions ending in 5 (15, 25, 35...): ±3 modifier
        // - Positions divisible by 3 (9, 12, 21...): ±2 modifier  
        // - Odd positions (1, 7, 11...): ±1 modifier
        // - Other even positions: No modifier
        
        if (position % 10 === 0) {
            return 0; // Positions ending in 0
        } else if (position % 10 === 5) {
            return Math.random() < 0.5 ? 3 : -3; // Positions ending in 5
        } else if (position % 3 === 0) {
            return Math.random() < 0.5 ? 2 : -2; // Divisible by 3
        } else if (position % 2 === 1) {
            return Math.random() < 0.5 ? 1 : -1; // Odd positions
        } else {
            return 0; // Other even positions
        }
    }

    private validate20_30Rule(currentPosition: number, targetPosition: number, distance: number): boolean {
        // Fields 1-85: max 20 fields in any direction
        if (currentPosition <= 85) {
            return distance <= 20;
        }

        // Fields 86-100: max 30 fields backward, max 20 fields forward
        if (currentPosition > 85) {
            if (targetPosition > currentPosition) {
                // Moving forward: max 20 fields
                return distance <= 20;
            } else {
                // Moving backward: max 30 fields
                return distance <= 30;
            }
        }

        return false;
    }
}