package main

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"

	"github.com/spf13/cobra"
)

var (
	batchSourceType      string
	batchInputs          []string
	batchTargetType      string
	batchTargetDir       string
	batchPackageName     string
	batchSchemaFilter    string
	batchFlattenSchema   bool
	batchNullableTypes   string
	batchNullableArrays  string
	batchContinueOnError bool
	batchKeepGoing       bool
	batchDryRun          bool
)

var batchCmd = &cobra.Command{
	Use:   "batch",
	Short: "Convert many input files to a target format in one run",
	Long: `Convert each input file independently to the target format.

Unlike 'convert --from-list', which merges all inputs into one output, batch
mode writes one output per input into --to-dir. The output is named after the
input file (without its extension). Directory-style targets (gorm, bun,
drizzle) get a sub-directory per input.

Inputs are given with --input, which accepts file paths and glob patterns and
may be repeated or comma-separated. Inputs are processed in sorted order and
duplicates are removed. The command exits non-zero if any input fails.

For named, multi-step workflows use 'relspec job run' instead.

Examples:
  # Convert every DBML file in a directory to JSON
  relspec batch --from dbml --input "schemas/*.dbml" --to json --to-dir out/

  # Convert specific files to GORM models, one package directory per input
  relspec batch --from json --input a.json,b.json \
                --to gorm --to-dir models/ --package models

  # Validate everything first, writing nothing
  relspec batch --from yaml --input "specs/*.yaml" --to pgsql --to-dir sql/ --dry-run

  # Report all failures instead of stopping at the first
  relspec batch --from json --input "*.json" --to yaml --to-dir out/ --keep-going`,
	RunE: runBatch,
}

func init() {
	batchCmd.Flags().StringVar(&batchSourceType, "from", "", "Source format for every input (dbml, dctx, drawdb, graphql, json, yaml, gorm, bun, drizzle, prisma, typeorm, sqlite)")
	batchCmd.Flags().StringSliceVar(&batchInputs, "input", nil, "Input file path or glob pattern (repeatable, comma-separated)")
	batchCmd.Flags().StringVar(&batchTargetType, "to", "", "Target format")
	batchCmd.Flags().StringVar(&batchTargetDir, "to-dir", "", "Output directory; one output per input is written here")
	batchCmd.Flags().StringVar(&batchPackageName, "package", "", "Package name (for code generation formats like gorm/bun)")
	batchCmd.Flags().StringVar(&batchSchemaFilter, "schema", "", "Filter to a specific schema by name")
	batchCmd.Flags().BoolVar(&batchFlattenSchema, "flatten-schema", false, "Flatten schema.table names to schema_table")
	batchCmd.Flags().StringVar(&batchNullableTypes, "types", "", "Nullable type package for code-gen writers (bun/gorm)")
	batchCmd.Flags().StringVar(&batchNullableArrays, "array-nullable", "", "Nullable array representation for the Bun writer")
	batchCmd.Flags().BoolVar(&batchContinueOnError, "continue-on-error", false, "Prepend \\set ON_ERROR_STOP off to generated SQL (pgsql output only)")
	batchCmd.Flags().BoolVar(&batchKeepGoing, "keep-going", false, "Process remaining inputs after a failure; still exits non-zero")
	batchCmd.Flags().BoolVar(&batchDryRun, "dry-run", false, "Read and validate every input and print the plan without writing any output")

	for _, f := range []string{"from", "input", "to", "to-dir"} {
		if err := batchCmd.MarkFlagRequired(f); err != nil {
			fmt.Fprintf(os.Stderr, "Error marking %s flag as required: %v\n", f, err)
		}
	}
}

// batchDirTargets are writers that emit a directory of files rather than one file.
var batchDirTargets = map[string]bool{"gorm": true, "bun": true, "drizzle": true}

// batchExtensions maps single-file target formats to their output extension.
var batchExtensions = map[string]string{
	"dbml": ".dbml", "dctx": ".dctx", "drawdb": ".ddb", "json": ".json",
	"yaml": ".yaml", "yml": ".yaml", "pgsql": ".sql", "postgres": ".sql",
	"postgresql": ".sql", "sql": ".sql", "mssql": ".sql", "sqlserver": ".sql",
	"mssql2016": ".sql", "mssql2017": ".sql", "mssql2019": ".sql", "mssql2022": ".sql",
	"sqlite": ".sql", "sqlite3": ".sql", "prisma": ".prisma", "typeorm": ".ts",
	"graphql": ".graphql", "gql": ".graphql",
}

// expandBatchInputs resolves paths and glob patterns into a sorted,
// de-duplicated file list. A pattern that matches nothing is an error.
func expandBatchInputs(patterns []string) ([]string, error) {
	seen := map[string]bool{}
	var files []string
	for _, p := range patterns {
		p = strings.TrimSpace(p)
		if p == "" {
			continue
		}
		matches, err := filepath.Glob(p)
		if err != nil {
			return nil, fmt.Errorf("invalid pattern %q: %w", p, err)
		}
		if len(matches) == 0 {
			return nil, fmt.Errorf("no files match %q", p)
		}
		for _, m := range matches {
			if !seen[m] {
				seen[m] = true
				files = append(files, m)
			}
		}
	}
	if len(files) == 0 {
		return nil, fmt.Errorf("no input files given")
	}
	sort.Strings(files)
	return files, nil
}

// batchOutputPaths returns the output path for each input. It errors when two
// inputs would collide on the same output name.
func batchOutputPaths(files []string, targetType, dir string) ([]string, error) {
	key := strings.ToLower(targetType)
	ext := ""
	if !batchDirTargets[key] {
		var ok bool
		if ext, ok = batchExtensions[key]; !ok {
			return nil, fmt.Errorf("unsupported target format: %s", targetType)
		}
	}
	outs := make([]string, len(files))
	owner := map[string]string{}
	for i, f := range files {
		stem := strings.TrimSuffix(filepath.Base(f), filepath.Ext(f))
		out := filepath.Join(dir, stem+ext)
		if prev, dup := owner[out]; dup {
			return nil, fmt.Errorf("inputs %s and %s would both write %s", prev, f, out)
		}
		owner[out] = f
		outs[i] = out
	}
	return outs, nil
}

func runBatch(cmd *cobra.Command, args []string) error {
	files, err := expandBatchInputs(batchInputs)
	if err != nil {
		return err
	}
	outs, err := batchOutputPaths(files, batchTargetType, batchTargetDir)
	if err != nil {
		return err
	}

	fmt.Fprintf(os.Stderr, "\n=== RelSpec Batch Converter ===\n")
	fmt.Fprintf(os.Stderr, "Started at: %s\n", getCurrentTimestamp())
	fmt.Fprintf(os.Stderr, "Inputs: %d file(s), %s -> %s\n\n", len(files), batchSourceType, batchTargetType)

	out := outWriter(cmd)
	if batchDryRun {
		fmt.Fprintf(out, "RelSpec batch plan (dry run - nothing written):\n")
	}

	var failed []string
	for i, f := range files {
		fmt.Fprintf(os.Stderr, "[%d/%d] %s -> %s\n", i+1, len(files), f, outs[i])
		if err := processBatchItem(cmd, f, outs[i]); err != nil {
			fmt.Fprintf(os.Stderr, "      ✗ %v\n", err)
			failed = append(failed, fmt.Sprintf("%s: %v", f, err))
			if !batchKeepGoing {
				break
			}
			continue
		}
		fmt.Fprintf(os.Stderr, "      ✓ done\n")
	}

	fmt.Fprintf(os.Stderr, "\n=== Batch Complete: %d ok, %d failed ===\n", len(files)-len(failed), len(failed))
	if len(failed) > 0 {
		return fmt.Errorf("batch finished with %d failure(s):\n  %s", len(failed), strings.Join(failed, "\n  "))
	}
	return nil
}

func processBatchItem(cmd *cobra.Command, in, outPath string) error {
	db, err := readDatabaseForConvert(batchSourceType, in, "")
	if err != nil {
		return fmt.Errorf("failed to read source: %w", err)
	}
	finalizeCommentedRefs(db, stderrWarn)

	if batchDryRun {
		if err := validateWriteTarget(db, batchTargetType, batchPackageName, batchSchemaFilter, ""); err != nil {
			return fmt.Errorf("dry run validation failed: %w", err)
		}
		w := outWriter(cmd)
		fmt.Fprintf(w, "  %s -> %s (database '%s')\n", in, outPath, db.Name)
		printDryRunPlan(w, db)
		return nil
	}

	if err := os.MkdirAll(batchTargetDir, 0o755); err != nil {
		return fmt.Errorf("failed to create output directory: %w", err)
	}
	if err := writeDatabase(db, batchTargetType, outPath, batchPackageName, batchSchemaFilter, batchFlattenSchema, batchNullableTypes, batchNullableArrays, batchContinueOnError, ""); err != nil {
		return fmt.Errorf("failed to write target: %w", err)
	}
	return nil
}