package cmd

import (
	"bufio"
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"runtime/trace"

	"github.com/cubicdaiya/gonp"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"gopkg.in/yaml.v3"

	"github.com/sqlc-dev/sqlc/internal/config"
	"github.com/sqlc-dev/sqlc/internal/debug"
	"github.com/sqlc-dev/sqlc/internal/info"
	"github.com/sqlc-dev/sqlc/internal/opts"
	"github.com/sqlc-dev/sqlc/internal/tracer"
)

func init() {
	createDBCmd.Flags().StringP("queryset", "", "", "name of the queryset to use")
	pushCmd.Flags().BoolP("dry-run", "", false, "dump push request (default: false)")
	initCmd.Flags().BoolP("v1", "", false, "generate v1 config yaml file")
	initCmd.Flags().BoolP("v2", "", true, "generate v2 config yaml file")
	initCmd.MarkFlagsMutuallyExclusive("v1", "v2")
	parseCmd.Flags().StringP("dialect", "d", "", "SQL dialect to use (postgresql, mysql, or sqlite)")
}

// Do runs the command logic.
func Do(args []string, stdin io.Reader, stdout io.Writer, stderr io.Writer) int {
	rootCmd := &cobra.Command{Use: "sqlc", SilenceUsage: true}
	rootCmd.PersistentFlags().StringP("file", "f", "", "specify an alternate config file (default: sqlc.yaml)")
	rootCmd.PersistentFlags().Bool("no-remote", false, "disable remote execution (default: false)")
	rootCmd.PersistentFlags().Bool("remote", false, "enable remote execution (default: false)")

	rootCmd.AddCommand(checkCmd)
	rootCmd.AddCommand(createDBCmd)
	rootCmd.AddCommand(diffCmd)
	rootCmd.AddCommand(genCmd)
	rootCmd.AddCommand(initCmd)
	rootCmd.AddCommand(parseCmd)
	rootCmd.AddCommand(versionCmd)
	rootCmd.AddCommand(verifyCmd)
	rootCmd.AddCommand(pushCmd)
	rootCmd.AddCommand(NewCmdVet())

	rootCmd.SetArgs(args)
	rootCmd.SetIn(stdin)
	rootCmd.SetOut(stdout)
	rootCmd.SetErr(stderr)

	ctx := context.Background()
	if debug.Debug.Trace != "" {
		tracectx, cleanup, err := tracer.Start(ctx)
		if err != nil {
			fmt.Printf("failed to start trace: %v\n", err)
			return 1
		}
		ctx = tracectx
		defer cleanup()
	}
	if err := rootCmd.ExecuteContext(ctx); err != nil {
		if exitError, ok := err.(*exec.ExitError); ok {
			return exitError.ExitCode()
		} else {
			return 1
		}
	}
	return 0
}

var version string

var versionCmd = &cobra.Command{
	Use:   "version",
	Short: "Print the sqlc version number",
	RunE: func(cmd *cobra.Command, args []string) error {
		defer trace.StartRegion(cmd.Context(), "version").End()
		if version == "" {
			fmt.Fprintf(cmd.OutOrStdout(), "%s\n", info.Version)
		} else {
			fmt.Fprintf(cmd.OutOrStdout(), "%s\n", version)
		}
		return nil
	},
}

var initCmd = &cobra.Command{
	Use:   "init",
	Short: "Create an empty sqlc.yaml settings file",
	RunE: func(cmd *cobra.Command, args []string) error {
		useV1, err := cmd.Flags().GetBool("v1")
		if err != nil {
			return err
		}
		var yamlConfig interface{}
		if useV1 {
			yamlConfig = config.V1GenerateSettings{Version: "1"}
		} else {
			yamlConfig = config.Config{Version: "2"}
		}

		defer trace.StartRegion(cmd.Context(), "init").End()
		file := "sqlc.yaml"
		if f := cmd.Flag("file"); f != nil && f.Changed {
			file = f.Value.String()
			if file == "" {
				return fmt.Errorf("file argument is empty")
			}
		}
		if _, err := os.Stat(file); !os.IsNotExist(err) {
			fmt.Printf("%s is already created\n", file)
			return nil
		}
		blob, err := yaml.Marshal(yamlConfig)
		if err != nil {
			return err
		}
		err = os.WriteFile(file, blob, 0644)
		if err != nil {
			return err
		}
		configDoc := "https://docs.sqlc.dev/en/stable/reference/config.html"
		fmt.Printf(
			"%s is added. Please visit %s to learn more about configuration\n",
			file,
			configDoc,
		)
		return nil
	},
}

type Env struct {
	DryRun     bool
	Debug      opts.Debug
	Experiment opts.Experiment
	Remote     bool
	NoRemote   bool
}

func ParseEnv(c *cobra.Command) Env {
	dr := c.Flag("dry-run")
	r := c.Flag("remote")
	nr := c.Flag("no-remote")
	return Env{
		DryRun:     dr != nil && dr.Changed,
		Debug:      opts.DebugFromEnv(),
		Experiment: opts.ExperimentFromEnv(),
		Remote:     r != nil && r.Value.String() == "true",
		NoRemote:   nr != nil && nr.Value.String() == "true",
	}
}

var ErrPluginProcessDisabled = errors.New("plugin: process-based plugins disabled via SQLCDEBUG=processplugins=0")

func (e *Env) Validate(cfg *config.Config) error {
	for _, plugin := range cfg.Plugins {
		if plugin.Process != nil && !e.Debug.ProcessPlugins {
			return ErrPluginProcessDisabled
		}
	}
	return nil
}

func getConfigPath(stderr io.Writer, f *pflag.Flag) (string, string) {
	if f != nil && f.Changed {
		file := f.Value.String()
		if file == "" {
			fmt.Fprintln(stderr, "error parsing config: file argument is empty")
			os.Exit(1)
		}
		abspath, err := filepath.Abs(file)
		if err != nil {
			fmt.Fprintf(stderr, "error parsing config: absolute file path lookup failed: %s\n", err)
			os.Exit(1)
		}
		return filepath.Dir(abspath), filepath.Base(abspath)
	} else {
		wd, err := os.Getwd()
		if err != nil {
			fmt.Fprintln(stderr, "error parsing sqlc.json: file does not exist")
			os.Exit(1)
		}
		return wd, ""
	}
}

var genCmd = &cobra.Command{
	Use:   "generate",
	Short: "Generate source code from SQL",
	RunE: func(cmd *cobra.Command, args []string) error {
		defer trace.StartRegion(cmd.Context(), "generate").End()
		stderr := cmd.ErrOrStderr()
		dir, name := getConfigPath(stderr, cmd.Flag("file"))
		output, err := Generate(cmd.Context(), dir, name, &Options{
			Env:    ParseEnv(cmd),
			Stderr: stderr,
		})
		if err != nil {
			os.Exit(1)
		}
		defer trace.StartRegion(cmd.Context(), "writefiles").End()
		for filename, source := range output {
			os.MkdirAll(filepath.Dir(filename), 0755)
			if err := os.WriteFile(filename, []byte(source), 0644); err != nil {
				fmt.Fprintf(stderr, "%s: %s\n", filename, err)
				return err
			}
		}
		return nil
	},
}

var checkCmd = &cobra.Command{
	Use:   "compile",
	Short: "Statically check SQL for syntax and type errors",
	RunE: func(cmd *cobra.Command, args []string) error {
		defer trace.StartRegion(cmd.Context(), "compile").End()
		stderr := cmd.ErrOrStderr()
		dir, name := getConfigPath(stderr, cmd.Flag("file"))
		_, err := Generate(cmd.Context(), dir, name, &Options{
			Env:    ParseEnv(cmd),
			Stderr: stderr,
		})
		if err != nil {
			os.Exit(1)
		}
		return nil
	},
}

func getLines(f []byte) []string {
	fp := bytes.NewReader(f)
	scanner := bufio.NewScanner(fp)
	lines := make([]string, 0)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}
	return lines
}

func filterHunks[T gonp.Elem](uniHunks []gonp.UniHunk[T]) []gonp.UniHunk[T] {
	var out []gonp.UniHunk[T]
	for i, uniHunk := range uniHunks {
		var changed bool
		for _, e := range uniHunk.GetChanges() {
			switch e.GetType() {
			case gonp.SesDelete:
				changed = true
			case gonp.SesAdd:
				changed = true
			}
		}
		if changed {
			out = append(out, uniHunks[i])
		}
	}
	return out
}

var diffCmd = &cobra.Command{
	Use:   "diff",
	Short: "Compare the generated files to the existing files",
	RunE: func(cmd *cobra.Command, args []string) error {
		defer trace.StartRegion(cmd.Context(), "diff").End()
		stderr := cmd.ErrOrStderr()
		dir, name := getConfigPath(stderr, cmd.Flag("file"))
		opts := &Options{
			Env:    ParseEnv(cmd),
			Stderr: stderr,
		}
		if err := Diff(cmd.Context(), dir, name, opts); err != nil {
			os.Exit(1)
		}
		return nil
	},
}