package build

import (
	"fmt"
	"log"
	"strings"

	"git.secnex.io/secnex/pgson/schema"
	"git.secnex.io/secnex/pgson/sql"
)

func CreateTable(s *schema.Table) (*string, error) {
	if err := sql.ValidateIdent(s.Name); err != nil {
		return nil, err
	}

	var cols, comments, pks []string

	for _, f := range s.Schema {
		if err := sql.ValidateIdent(f.Name); err != nil {
			log.Printf("Invalid identifier: %s", f.Name)
			return nil, err
		}

		pgType, err := sql.ValidateType(f.Type)
		if err != nil {
			log.Printf("Invalid type: %s", f.Type)
			return nil, err
		}

		if f.Type == "hash" {
			if _, ok := sql.AlgorithmMap[strings.ToLower(*f.Algorithm)]; !ok {
				log.Printf("Invalid algorithm: %s", *f.Algorithm)
				return nil, fmt.Errorf("invalid algorithm: %s", *f.Algorithm)
			}
		}

		colParts := []string{sql.QuoteIdent(f.Name), pgType}
		if f.Nullable != nil && !*f.Nullable {
			colParts = append(colParts, "NOT NULL")
		}

		if f.Unique != nil && *f.Unique {
			colParts = append(colParts, "UNIQUE")
		}

		// Auto-generate UUID for UUID primary keys if no default is specified
		if f.Primary != nil && *f.Primary && f.Type == "uuid" {
			if f.Default == nil || *f.Default == "" {
				colParts = append(colParts, "DEFAULT gen_random_uuid()")
			} else {
				def, err := sql.ValidateDefault(*f.Default)
				if err != nil {
					return nil, err
				}
				colParts = append(colParts, "DEFAULT "+def)
			}
		} else if f.Default != nil && *f.Default != "" {
			def, err := sql.ValidateDefault(*f.Default)
			if err != nil {
				return nil, err
			}
			colParts = append(colParts, "DEFAULT "+def)
		}

		if f.References != nil {
			if err := sql.ValidateIdent(f.References.Table); err != nil {
				log.Printf("Invalid references table: %s", f.References.Table)
				return nil, err
			}
			if err := sql.ValidateIdent(f.References.Column); err != nil {
				log.Printf("Invalid references column: %s", f.References.Column)
				return nil, err
			}
			onDelete, err := sql.ValidateAction(f.References.OnDelete)
			if err != nil {
				log.Printf("Invalid on delete: %s", f.References.OnDelete)
				return nil, err
			}
			onUpdate, err := sql.ValidateAction(f.References.OnUpdate)
			if err != nil {
				log.Printf("Invalid on update: %s", f.References.OnUpdate)
				return nil, err
			}
			fk := fmt.Sprintf("REFERENCES %s(%s) ON DELETE %s ON UPDATE %s", sql.QuoteIdent(f.References.Table), sql.QuoteIdent(f.References.Column), onDelete, onUpdate)
			colParts = append(colParts, fk)
		}

		cols = append(cols, strings.Join(colParts, " "))
		if f.Primary != nil && *f.Primary {
			pks = append(pks, sql.QuoteIdent(f.Name))
		}

		if f.Comment != nil {
			comments = append(comments, fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s';", sql.QuoteIdent(s.Name), sql.QuoteIdent(f.Name), *f.Comment))
		}
	}

	if len(pks) > 0 {
		cols = append(cols, "PRIMARY KEY ("+strings.Join(pks, ", ")+")")
	}

	ddl := fmt.Sprintf(sql.DDL_CREATE_TABLE, sql.QuoteIdent(s.Name), strings.Join(cols, ",\n  "))
	if len(comments) > 0 {
		ddl += "\n" + strings.Join(comments, "\n")
	}

	return &ddl, nil
}