package create

import (
	. "ersteller-lib"
	"ersteller-lib/starter/env"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"runtime"
	"strings"
)

type DatabaseType string

const (
	DatabaseTypePostgres DatabaseType = "postgres"
	DataBaseTypeSqlite   DatabaseType = "sqlite"
)

type Params struct {
	DbType       DatabaseType
	ProjectDir   string
	ModuleName   string
	GoPath       string
	OverwriteEnv bool
}

type StarterCreator struct {
	params  Params
	thisDir string
}

func NewStarterCreator(params Params) StarterCreator {
	// Validate target directory parameter
	if params.ProjectDir == "" {
		log.Printf("StarterCreator.Create: ProjectDir is empty; nothing to do")
		panic("ProjectDir is empty; nothing to do")
	}

	thisDir := GetPathToThisDir()
	return StarterCreator{
		params:  params,
		thisDir: thisDir,
	}
}

func GetPathToThisDir() string {
	// Resolve the path to the starter main.go located at ../main.go relative to this file
	_, thisFile, _, ok := runtime.Caller(0)
	if !ok {
		log.Printf("StarterCreator.Create: unable to resolve current file location via runtime.Caller")
		panic("unable to resolve current file location via runtime.Caller")
	}
	thisDir := filepath.Dir(thisFile)
	return thisDir
}

// Create reads the starter main.go file bundled with this package
// and writes it into the target project directory as main.go.
// Minimal, side-effecting function with internal error logging to keep API unchanged.
func (s StarterCreator) Create() {
	Debug("StarterCreator.Create")
	starterMainPath := filepath.Join(s.thisDir, "..", "main.go")

	// Read starter main.go
	content, err := os.ReadFile(starterMainPath)
	if err != nil {
		log.Printf("StarterCreator.Create: failed to read starter main.go at %s: %v", starterMainPath, err)
		return
	}

	// Ensure target directory exists
	if err := os.MkdirAll(s.params.ProjectDir, 0o755); err != nil {
		log.Printf("StarterCreator.Create: failed to create target directory %s: %v", s.params.ProjectDir, err)
		return
	}

	// Write to <ProjectDir>/main.go
	targetPath := filepath.Join(s.params.ProjectDir, "main.go")
	content = s.replaceImports(content)
	must(os.WriteFile(targetPath, content, 0o644))
	log.Printf("StarterCreator.Create: wrote starter main.go to %s", targetPath)

	s.copyFile("../go.work.template", "go.work")
	s.copyFile("../../template.air.toml", ".air.toml")
	//s.copyGoMod()
	//s.executeGoModTidy()
	s.executeGetPrismaClient()

	if s.params.DbType == DataBaseTypeSqlite {
		must(os.MkdirAll(filepath.Join(s.params.ProjectDir, "db"), 0o755))
	}
	s.copySchema()

	must(os.MkdirAll(filepath.Join(s.params.ProjectDir, "scripts"), 0o755))
	s.copyFile("../../scripts/db-push.sh", "scripts/db-push.sh")

	if s.params.DbType == DataBaseTypeSqlite {
		s.executeDbPush()
	}

	s.copyFile("../.gitignore", ".gitignore")

	s.createEnvironment()
	directories := []string{
		"index",
		"page",
		"routes",
		"static",
		"ent",
	}
	for _, dir := range directories {
		s.copyDirectoryRecursive(path.Join(s.thisDir, "..", dir), path.Join(s.params.ProjectDir, dir))
	}
	s.copySchemaFiles()
}

func (s StarterCreator) copySchemaFiles() {
	s.copyFile("../../schema/ent/pagination_query.tmpl", "ent/pagination_query.tmpl")
	content, err := os.ReadFile(filepath.Join(s.thisDir, "../generate_schema.go"))
	must(err)
	//content = s.replaceImports(content)
	must(os.WriteFile(filepath.Join(s.params.ProjectDir, "generate_schema.go"), content, 0o644))
}

func (s StarterCreator) createEnvironment() {
	if err := os.MkdirAll(s.params.ProjectDir+"/env", 0o755); err != nil {
		log.Printf("StarterCreator.Create: failed to create env target directory%v", err)
		return
	}
	//s.copyFile("../env/environment.go", "env/environment.go")
	content, err := os.ReadFile(filepath.Join(s.thisDir, "../env/environment.go"))
	must(err)
	must(os.WriteFile(filepath.Join(s.params.ProjectDir, "env/environment.go"), content, 0o644))

	must(env.GenerateEnvFile(s.params.ProjectDir, s.params.OverwriteEnv))

}

func (s StarterCreator) executeDbPush() {
	// After copying create_db.sh, run it with the project directory as the root
	scriptPath := filepath.Join(s.params.ProjectDir, "scripts", "db-push.sh")
	if runtime.GOOS == "windows" {
		log.Printf("StarterCreator.Create: skipping create_db.sh execution on Windows")
		return
	}
	if err := os.Chmod(scriptPath, 0o755); err != nil {
		log.Printf("StarterCreator.Create: failed to make create_db.sh executable: %v", err)
		return
	}

	cmd := exec.Command("/bin/sh", scriptPath)
	cmd.Dir = s.params.ProjectDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
		log.Printf("StarterCreator.Create: failed to run create_db.sh: %v", err)
	} else {
		log.Printf("StarterCreator.Create: successfully ran create_db.sh in %s", s.params.ProjectDir)
	}
}

func (s StarterCreator) copyFile(src string, dst string) {
	content, err := os.ReadFile(filepath.Join(s.thisDir, src))
	must(err)
	must(os.WriteFile(filepath.Join(s.params.ProjectDir, dst), content, 0o644))
}

func (s StarterCreator) copyDirectoryRecursive(src string, dst string) {
	must(os.MkdirAll(dst, 0o755))
	entries, err := os.ReadDir(src)
	must(err)
	for _, entry := range entries {
		srcPath := filepath.Join(src, entry.Name())
		dstPath := filepath.Join(dst, entry.Name())
		Debug("copying srcPath: ", srcPath, " to dstPath: ", dstPath)
		if entry.IsDir() {
			s.copyDirectoryRecursive(srcPath, dstPath)
			continue
		}
		content, err := os.ReadFile(srcPath)
		content = s.replaceImports(content)
		must(err)
		must(os.WriteFile(filepath.Join(dstPath), content, 0o644))
	}
}

func (s StarterCreator) copySchema() {
	content, err := os.ReadFile(filepath.Join(s.thisDir, "../../schema_template.prisma"))
	must(err)

	if s.params.DbType == DataBaseTypeSqlite {
		pgBlock := "datasource db {\n  provider = \"postgresql\"\n  url      = env(\"DATABASE_URL\")\n}\n"
		sqliteBlock := "datasource db {\n  provider = \"sqlite\"\n  url      = \"file:./db/sqlite.db\"\n}\n"
		contentStr := string(content)
		contentStr = strings.Replace(contentStr, pgBlock, sqliteBlock, 1)
		contentStr = strings.ReplaceAll(contentStr, " @db.Timestamptz(3)", "")
		contentStr = strings.ReplaceAll(contentStr, " @db.Timestamp(6)", "")
		content = []byte(contentStr)
	}

	must(os.WriteFile(filepath.Join(s.params.ProjectDir, "schema.prisma"), content, 0o644))
}

func (s StarterCreator) copyGoMod() {
	content, err := os.ReadFile(filepath.Join(s.thisDir, "../go.mod.template"))
	must(err)
	contentString := InlineTemplate(string(content), struct {
		ModuleName string
	}{
		ModuleName: s.params.ModuleName,
	})
	must(os.WriteFile(filepath.Join(s.params.ProjectDir, "go.mod"), []byte(contentString), 0o644))
}

func (s StarterCreator) executeGoModTidy() {
	goCommand := s.getGoCommand()
	cmd := exec.Command(goCommand, "mod", "tidy")
	cmd.Dir = s.params.ProjectDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	must(cmd.Run())
}

func (s StarterCreator) getGoCommand() string {
	goCommand := "go"
	if s.params.GoPath != "" {
		goCommand = s.params.GoPath
	}
	return goCommand
}

func (s StarterCreator) executeGetPrismaClient() {
	goCommand := s.getGoCommand()
	cmd := exec.Command(goCommand, "get", "github.com/steebchen/prisma-client-go")
	cmd.Dir = s.params.ProjectDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	must(cmd.Run())
}

func (s StarterCreator) replaceImports(content []byte) []byte {
	contentString := string(content)
	contentString = strings.ReplaceAll(contentString, "\"ersteller-lib/starter/", fmt.Sprint("\"", s.params.ModuleName, "/"))
	return []byte(contentString)
}

func must(err error) {
	if err != nil {
		panic(err)
	}
}