package config

import (
	"fmt"
	"io"
	"path/filepath"

	yaml "gopkg.in/yaml.v3"

	golang "github.com/sqlc-dev/sqlc/internal/codegen/golang/opts"
)

type V1GenerateSettings struct {
	Version   string              `json:"version" yaml:"version"`
	Cloud     Cloud               `json:"cloud" yaml:"cloud"`
	Packages  []v1PackageSettings `json:"packages" yaml:"packages"`
	Overrides []golang.Override   `json:"overrides,omitempty" yaml:"overrides,omitempty"`
	Rename    map[string]string   `json:"rename,omitempty" yaml:"rename,omitempty"`
	Rules     []Rule              `json:"rules" yaml:"rules"`
}

type v1PackageSettings struct {
	Name                      string            `json:"name" yaml:"name"`
	Engine                    Engine            `json:"engine,omitempty" yaml:"engine"`
	Database                  *Database         `json:"database,omitempty" yaml:"database"`
	Analyzer                  Analyzer          `json:"analyzer" yaml:"analyzer"`
	Path                      string            `json:"path" yaml:"path"`
	Schema                    Paths             `json:"schema" yaml:"schema"`
	Queries                   Paths             `json:"queries" yaml:"queries"`
	EmitInterface             bool              `json:"emit_interface" yaml:"emit_interface"`
	EmitJSONTags              bool              `json:"emit_json_tags" yaml:"emit_json_tags"`
	JsonTagsIDUppercase       bool              `json:"json_tags_id_uppercase" yaml:"json_tags_id_uppercase"`
	EmitDBTags                bool              `json:"emit_db_tags" yaml:"emit_db_tags"`
	EmitPreparedQueries       bool              `json:"emit_prepared_queries" yaml:"emit_prepared_queries"`
	EmitExactTableNames       bool              `json:"emit_exact_table_names,omitempty" yaml:"emit_exact_table_names"`
	EmitEmptySlices           bool              `json:"emit_empty_slices,omitempty" yaml:"emit_empty_slices"`
	EmitExportedQueries       bool              `json:"emit_exported_queries,omitempty" yaml:"emit_exported_queries"`
	EmitResultStructPointers  bool              `json:"emit_result_struct_pointers" yaml:"emit_result_struct_pointers"`
	EmitParamsStructPointers  bool              `json:"emit_params_struct_pointers" yaml:"emit_params_struct_pointers"`
	EmitMethodsWithDBArgument bool              `json:"emit_methods_with_db_argument" yaml:"emit_methods_with_db_argument"`
	EmitPointersForNullTypes  bool              `json:"emit_pointers_for_null_types" yaml:"emit_pointers_for_null_types"`
	EmitEnumValidMethod       bool              `json:"emit_enum_valid_method,omitempty" yaml:"emit_enum_valid_method"`
	EmitAllEnumValues         bool              `json:"emit_all_enum_values,omitempty" yaml:"emit_all_enum_values"`
	EmitSqlAsComment          bool              `json:"emit_sql_as_comment,omitempty" yaml:"emit_sql_as_comment"`
	JSONTagsCaseStyle         string            `json:"json_tags_case_style,omitempty" yaml:"json_tags_case_style"`
	SQLPackage                string            `json:"sql_package" yaml:"sql_package"`
	SQLDriver                 string            `json:"sql_driver" yaml:"sql_driver"`
	Overrides                 []golang.Override `json:"overrides" yaml:"overrides"`
	OutputBatchFileName       string            `json:"output_batch_file_name,omitempty" yaml:"output_batch_file_name"`
	OutputDBFileName          string            `json:"output_db_file_name,omitempty" yaml:"output_db_file_name"`
	OutputModelsFileName      string            `json:"output_models_file_name,omitempty" yaml:"output_models_file_name"`
	OutputQuerierFileName     string            `json:"output_querier_file_name,omitempty" yaml:"output_querier_file_name"`
	OutputCopyFromFileName    string            `json:"output_copyfrom_file_name,omitempty" yaml:"output_copyfrom_file_name"`
	OutputFilesSuffix         string            `json:"output_files_suffix,omitempty" yaml:"output_files_suffix"`
	StrictFunctionChecks      bool              `json:"strict_function_checks" yaml:"strict_function_checks"`
	StrictOrderBy             *bool             `json:"strict_order_by" yaml:"strict_order_by"`
	QueryParameterLimit       *int32            `json:"query_parameter_limit,omitempty" yaml:"query_parameter_limit"`
	OmitSqlcVersion           bool              `json:"omit_sqlc_version,omitempty" yaml:"omit_sqlc_version"`
	OmitUnusedStructs         bool              `json:"omit_unused_structs,omitempty" yaml:"omit_unused_structs"`
	Rules                     []string          `json:"rules" yaml:"rules"`
	BuildTags                 string            `json:"build_tags,omitempty" yaml:"build_tags"`
}

func v1ParseConfig(rd io.Reader) (Config, error) {
	dec := yaml.NewDecoder(rd)
	dec.KnownFields(true)
	var settings V1GenerateSettings
	var config Config
	if err := dec.Decode(&settings); err != nil {
		return config, err
	}
	if settings.Version == "" {
		return config, ErrMissingVersion
	}
	if settings.Version != "1" {
		return config, ErrUnknownVersion
	}
	if len(settings.Packages) == 0 {
		return config, ErrNoPackages
	}
	if err := settings.ValidateGlobalOverrides(); err != nil {
		return config, err
	}
	for j := range settings.Packages {
		if settings.Packages[j].Path == "" {
			return config, ErrNoPackagePath
		}

		if settings.Packages[j].Name == "" {
			settings.Packages[j].Name = filepath.Base(settings.Packages[j].Path)
		}

		if settings.Packages[j].Engine == "" {
			settings.Packages[j].Engine = EnginePostgreSQL
		}
	}

	return settings.Translate(), nil
}

func (c *V1GenerateSettings) ValidateGlobalOverrides() error {
	engines := map[Engine]struct{}{}
	for _, pkg := range c.Packages {
		if _, ok := engines[pkg.Engine]; !ok {
			engines[pkg.Engine] = struct{}{}
		}
	}

	usesMultipleEngines := len(engines) > 1
	for _, oride := range c.Overrides {
		if usesMultipleEngines && oride.Engine == "" {
			return fmt.Errorf(`the "engine" field is required for global type overrides because your configuration uses multiple database engines`)
		}
	}
	return nil
}

func (c *V1GenerateSettings) Translate() Config {
	conf := Config{
		Version: c.Version,
		Cloud:   c.Cloud,
		Rules:   c.Rules,
	}

	for _, pkg := range c.Packages {
		if pkg.StrictOrderBy == nil {
			defaultValue := true
			pkg.StrictOrderBy = &defaultValue
		}
		conf.SQL = append(conf.SQL, SQL{
			Name:     pkg.Name,
			Engine:   pkg.Engine,
			Database: pkg.Database,
			Schema:   pkg.Schema,
			Queries:  pkg.Queries,
			Rules:    pkg.Rules,
			Analyzer: pkg.Analyzer,
			Gen: SQLGen{
				Go: &golang.Options{
					EmitInterface:             pkg.EmitInterface,
					EmitJsonTags:              pkg.EmitJSONTags,
					JsonTagsIdUppercase:       pkg.JsonTagsIDUppercase,
					EmitDbTags:                pkg.EmitDBTags,
					EmitPreparedQueries:       pkg.EmitPreparedQueries,
					EmitExactTableNames:       pkg.EmitExactTableNames,
					EmitEmptySlices:           pkg.EmitEmptySlices,
					EmitExportedQueries:       pkg.EmitExportedQueries,
					EmitResultStructPointers:  pkg.EmitResultStructPointers,
					EmitParamsStructPointers:  pkg.EmitParamsStructPointers,
					EmitMethodsWithDbArgument: pkg.EmitMethodsWithDBArgument,
					EmitPointersForNullTypes:  pkg.EmitPointersForNullTypes,
					EmitEnumValidMethod:       pkg.EmitEnumValidMethod,
					EmitAllEnumValues:         pkg.EmitAllEnumValues,
					EmitSqlAsComment:          pkg.EmitSqlAsComment,
					Package:                   pkg.Name,
					Out:                       pkg.Path,
					SqlPackage:                pkg.SQLPackage,
					SqlDriver:                 pkg.SQLDriver,
					Overrides:                 pkg.Overrides,
					JsonTagsCaseStyle:         pkg.JSONTagsCaseStyle,
					OutputBatchFileName:       pkg.OutputBatchFileName,
					OutputDbFileName:          pkg.OutputDBFileName,
					OutputModelsFileName:      pkg.OutputModelsFileName,
					OutputQuerierFileName:     pkg.OutputQuerierFileName,
					OutputCopyfromFileName:    pkg.OutputCopyFromFileName,
					OutputFilesSuffix:         pkg.OutputFilesSuffix,
					QueryParameterLimit:       pkg.QueryParameterLimit,
					OmitSqlcVersion:           pkg.OmitSqlcVersion,
					OmitUnusedStructs:         pkg.OmitUnusedStructs,
					BuildTags:                 pkg.BuildTags,
				},
			},
			StrictFunctionChecks: pkg.StrictFunctionChecks,
			StrictOrderBy:        pkg.StrictOrderBy,
		})
	}

	if len(c.Overrides) > 0 || len(c.Rename) > 0 {
		conf.Overrides.Go = &golang.GlobalOptions{
			Overrides: c.Overrides,
			Rename:    c.Rename,
		}
	}

	return conf
}